Abstract:
A reclinable ambulance cot used to load a patient into the back of an ambulance is provided. The cot includes a wheeled collapsible undercarriage carrying an articulated bed frame comprised of a leg segment, seat segment, and wheeled back segment. The articulated bed frame may be moved between an inclined, fully-reclined position, a chair position, and a plurality of positions therebetween. A lockable biasing device assists in the transition by urging the bed frame segments from the chair position to the fully-reclined position. The back segment further includes a pair of loading wheels at the ends of side extensions such that when the cot is in the inclined, fully-reclined position the loading wheels are at height sufficient to facilitate loading the reclined cot into the back of an ambulance, and in particular, into the back of an ambulance having a high transport deck.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/150,466, filed Aug. 24, 1999, which is incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to reclinable ambulance cots used to load patients into the back of an ambulance. More particularly, the present invention relates to a reclinable ambulance cot used to load a patient into the back of an ambulance, wherein situating the cot into a fully-reclined position elevates a loading end of the cot to a height which facilitates the loading of the reclined cot and a patient situated thereon into the ambulance. 
     In transporting emergency patients from their homes to a hospital for treatment, it is oftentimes necessary to remove the patient from his home using an ambulance cot, such as a stretcher, or the like, wherein the patient is situated thereon in a generally supine position. As well known in the art, such cots are typically provided with an undercarriage having a rollable base which facilitates transportation of the patient situated upon the cot to an ambulance parked near the patient&#39;s home. The undercarriage may be collapsed, thereby permitting the cot, its undercarriage, and the patient situated thereon to be rolled into the back of the ambulance in a fully-reclined position for transportation to the hospital. 
     However, in removing the patient from his home, it is sometimes difficult for paramedics to reach the patient with a fully-reclined cot, such as those of the prior art. Particularly, it is difficult for paramedics to traverse stairs to/from a second floor of the patient&#39;s home with a fully-reclined cot, or where the patient&#39;s home includes narrow hallways and doorways, through which maneuvering of a fully-reclined cot is extremely difficult, and sometime, impossible. In such situations, it is desirable for the cot to have a reduced “footprint,” such as that provided by a wheelchair or the like, to facilitate maneuvering of the cot and of a patient situated thereon through the patient&#39;s home. Once the cot has been removed to a location free from any obstructions of the patient&#39;s home, such as, to a location near the back of the ambulance, it is desirable for the cot to be fully-reclinable to facilitate rolling the cot into the back of an ambulance. 
     Accordingly, there is a need to provide a reclinable ambulance cot which is movable between a fully-reclined position, where a patient situated thereon is resting in a generally supine position, and a chair position, where a patient situated thereon is in a generally upright, sitting position. U.S. Pat. No. 3,289,219 to Ferneau, et al. is illustrative of attempts made in the prior art to provide a combined ambulance cot and rolling chair which is movable between a reclined position and a chair position. 
     However, it has been observed that prior art reclinable ambulance cots do not provide an elevated loading end which is sufficient in height to facilitate rolling of the fully-reclined cot into the back of the ambulance, and more particularly, into the back of an ambulance which has a high transport deck in excess of 30 inches above the ground. With such prior art cots it is oftentimes necessary for one paramedic to lift the loading end of the fully-reclined cot to an elevation sufficient to permit rolling of the cot into the back of the ambulance while another paramedic pushes the cot into the back of the ambulance. It should be appreciated by those of reasonable skill in the art that loading a patient situated upon a fully-reclined cot into the back of an ambulance in this prior-art manner is difficult, for example, for the paramedics lifting the cot. Furthermore, such lifting increases the risk of physical injury to both the carried patient and the lifting paramedics. 
     Accordingly, there is also a need to provide a reclinable ambulance cot which is movable between a chair position and a fully-reclined position in which a loading end of the fully-reclined cot is elevated to a height that permits rolling of the reclined cot into the back of an ambulance, and in particularly, into the back of an ambulance with a high deck without the need for additional lifting of the cot by paramedics. 
     Moreover, it has been observed that prior art reclinable ambulance cots do not easily transition from the chair position to the fully-reclined position. Due to the typically provided ratcheting mechanism on such prior art cots, paramedics must pull up and then lower the cot into its reclined position. This lowering operation with these prior art cots is jarring which can add further discomfort to the patient. 
     Accordingly, there is also a need to provide a reclinable ambulance cot which transitions smoothly between the chair~position and the fully-reclined position. 
     SUMMARY OF THE INVENTION 
     The above-mentioned needs are met by the present invention which provides a reclinable ambulance cot used to load a patient into the back of an ambulance. The cot of the present invention is movable between a fully-reclined position, wherein a patient situated thereon is in a generally supine position, and a chair position, wherein the patient situated thereon is generally upright in a seated position thereby providing a cot with a reduced footprint. 
     Additionally, the cot of the present invention includes a folding undercarriage pivotally mounting a support frame to a roller base. A segmented bed frame is adjustably connected to the support frame and includes a back segment, a leg segment, and seat segment. Included to back segment is a spacing bracket pivotably connected at one end thereof to the undercarriage and pivotably connected at another end thereof to the support frame. The leg segment is pivotably connected to the support frame, and provides a raisable footrest panel and a raisable footrest that may be used additionally as a pull handle. The seat segment is connected to the back segment and includes a linkage assembly that is connected to the leg segment. Accordingly, with the bed frame segments interconnected as such, moving the cot from the chair position to the fully-reclined position effect&#39;s vertical lifting of the back segment, thereby elevating a wheeled free loading end thereof to a height sufficient to facilitate loading the fully-reclined cot into the back of an ambulance, and more particularly, into the back of an ambulance having a high transport deck. 
     Furthermore, the back segment of the cot of the present invention includes an inclinable backrest frame that is pivotably connected at one end thereof to the support frame. The inclinable backrest frame is connected at another end thereof to a cross member spanning the width of the cot by a lockable extending member, preferably a gas spring. A second lockable extending member, also preferably a gas spring, is mounted within the linkage assembly of the seat segment. Accordingly, with these lockable extending members assisting in the transition of the cot between the chair position and the full-reclined position jarring of the cot is prevented. Moreover, these lockable extending members permit the cot of the present invention to be secured into an infinite number of positions between the chair position and the fully-reclined position thereby adding further to the comfort of the patient. 
     In one aspect, the present invention is a reclinable ambulance cot comprising a three-sided rectangular support frame, a roller base, and four legs pivotally mounted to the support frame and the roller base such that the legs may swing the roller base generally parallel to the support frame. Additionally, a pair of diagonal braces is pivotally mounted to the support frame and the roller base to releasably secure the legs perpendicular to the support frame. An articulated bed frame having a wheeled back segment is pivotally mounted to the support frame for movement at least between a chair position and a fully-reclined position in which the wheeled back segment is elevated to a sufficient height to permit rolling of the reclined cot into the back of an ambulance with a high transport deck. 
     In another aspect, the present invention is a reclinable cot comprising a three-sided rectangular support frame, a roller base, and four downwardly extending legs each having upper and lower ends. The lower ends of the legs are pivotally mounted to the four corners of the roller base and the upper ends of the legs are pivotally mounted to the support frame such that the legs may swing generally parallel to the support. Additionally provided is a pair of diagonal braces to normally brace the legs perpendicular to the support frame. The braces each having upper and lower links connected by an over-center hinge in which the lower links are pivotally mounted to the roller base and the upper links are pivotally mounted to the support frame, and an articulated bed frame constituted by a leg segment, a seat segment, and a wheeled back segment linked to each other. The bed frame is pivotally mounted to the support frame for movement between a chair position, in which the seat segment is horizontal and the leg and the wheeled back segments are generally vertical, and a fully-reclined position, in which all panels are inclined. In the fully-reclined position the wheeled back segment is elevated to a sufficient height to permit rolling of the reclined cot into the back of an ambulance with a high transport deck. 
     These and additional objects, features and advantages of the present invention will become apparent to those reasonably skilled in the art from the description which follows, and may be realized by means of the instrumentalities and combinations particularly pointed out in the claims appended hereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like reference numerals represent like parts, and wherein: 
     FIG. 1 is a side view of a reclinable ambulance cot according to a preferred embodiment of the present invention, showing the cot in a chair position; 
     FIG. 2 is a side view of the reclinable ambulance cot of FIG. 1, showing the cot in a fully-reclined position; and, 
     FIG. 3 is a rear view of the reclinable ambulance cot of FIG. 1, showing the cot in a chair position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to FIGS. 1-3, according to an embodiment of the present invention a reclinable ambulance cot  10  is shown. Preferably, both sides of the cot  10  are identical, and as such with reference to FIGS. 1 and 2, only one side of the cot  10  will be described herein. The reclinable ambulance cot  10  includes a collapsible undercarriage, generally indicated by  20 , supportably connecting a roller base  30  to a support frame  40 . Roller base  30  includes a generally rectangular frame having members  32 , connected in an end-to-end fashion, and conventional wheels  34  rotatably mounted within brackets  34   a ,  34   b  to frame members  32  at their respective ends of intersection. Preferably, the front brackets  34   a  are rotatably mounted to frame members  32  to facilitate steering and maneuvering of cot  10 , whereas the rear brackets  34   b  are fixedly mounted to frame members  32 . 
     The support frame  40  is rectangular in shape with three sides having frame members and a fourth side open to permit patient loading. The support frame  40  is generally comprising a pair of base members  42 , and cross member  55  (FIG.  3 ). Each of the pair of base members  42  may include a side shield  43  fixedly secured, such as, for example, by bolts, and an upright member  44  pivotably connected by fixed pin  45   a  and by locking pin  45   b . It is to be appreciated that locking pin  45   b  is coaxial with fixed pin  45   a . Upright member  44  pivots about the common axis of fixed pin  45   a  and locking pin  45   b  to move between an upward position, such as is shown in the FIGS. 1 and 2, wherein upright member  42  is generally coplanar with and extends upwardly from side shield  43 , and a downward position as indicated by the dashed line in FIG. 2, wherein upright member  44  is positioned over side shield  43 . Locking pin  45   b  is any conventional locking mechanism that is adapted to lock upright member  44  in either the upward position or the downward position. Alternatively, locking pin  45   b  may be adapted to lock upright member  44  in any angularly-offset position between the upward position and the downward position. Cross-member  55  is fixedly secured between a pair of side rail  53 , and is offset therefrom by a preselected distance, such as, by brackets  56 . 
     Undercarriage  20  includes two pairs of fixed-length legs  22 ,  57  pivotally mounted to the support frame  40  and the roller base  30  such that the legs  22 ,  57  may swing the roller base  30  generally parallel to the support frame. The first pair of fixed-length legs  22  pivotably connects a front end of roller base  30  to base member  42 . The second pair of fixed-length legs  57  pivotably connect a rear end of roller base  30 , preferably rear roller base member  32   a , to cross-member  55 . A pair of braces  24  is pivotally mounted diagonally to the support frame  40  and the roller base  30 . The pair of braces  24  releasably secures the legs  22 ,  57  perpendicularly to the support frame  40 . The pair of diagonal braces  24  normally brace the legs  22 ,  57  perpendicularly to the support frame  40 , in which the braces  24  each have both upper and lower links  23   a  and  23   b , respectively, connected by an over-center hinge  21 . Since each lower link  23   b  is pivotally mounted to the roller base  30  and each upper link  23   a  is pivotally mounted to the support frame  40 , breaking the over-center hinge  21  will permit the support frame to collapse along with roller base  30  into a retracted, compact orientation. A hand-operated level  97  is operatively connected to a conventional breaking mechanism (not shown) to facilitate the breaking or releasing of the braces  24  thereby permitting the roller base  30  to swing parallel to the support frame  40 . One such conventional breaking mechanism is disclosed by U.S. Pat. No. 3,289,219 to Ferneau et al., which is herein incorporated by reference. 
     Cot  10  further includes an articulated bed frame, generally indicated by  50 , which is adjustable between a chair position, such as shown in FIG. 1, and a fully-reclined position, such as shown in FIG.  2 . Bed frame  50  comprises three main segments namely, a wheeled back segment  52 , a leg segment  62  and a seat segment  72  operably connected to each other between the pair of base members  42 . Back segment  52  includes the pair of side rails  53  which are pivotably connected to rear ends of the pair of base members  42 , such as at first pivot point  91 . As such, with the wheeled back segment  52 , the seat segment  72 , and the leg segment  62  operably connected to each other in this fashion, when the cot is in the chair position, the seat segment  72  is generally horizontal and both the leg segment  62  and the wheeled back segment  52  are generally vertical relative to the base  30 . A wheel  81  is affixed to a free end  53   a  of each side rail  53 , defining a loading end of the cot  10  thereof. The wheels  81  may be rotatably connected to one another, such as by axle  82  as shown in FIG.  3 . 
     Back segment  52  further includes a frame-like backrest member  54  that is connected at a hinged end  54   b  (FIG. 3) thereof between the pair of side rails  53 , such as at second pivot point  92 . A first extending member or biasing spring  83  is connected at a first end to backrest member  54  adjacent a free end  54   a  thereof, and is connected at a second end to cross-member  55 . Biasing spring  83  provides a positive, tensile biasing force when activated. For example, biasing spring  83  is preferably a gas spring having a lockable valve therein, such as the locking gas springs sold under the trademark BLOC-O-LIFT by Stabilus of Gastonia, N.C. Preferably, biasing spring  83  is a model 2482MM-C0275N 135/99 BLOC-O-LIFT brand gas spring manufactured by Stabilus providing a 275-newton tensile biasing force when the locking mechanism thereof has been released. Lock release  84  is connected to backrest member  54  such that, depressing release  84  releases the locking mechanism within biasing spring  83 , thereby causing backrest member  54  to pivot about second pivot point  92  into an upright position shown with dashed line in FIG. 2 or any position therebetween shown by the arrow in FIG. 2 under the influence of the biasing force of spring  83 . Once release  84  is released, the locking mechanism within biasing spring  83  prevents further extension thereof, thereby locking backrest member  54  in the upright position or any of an infinite number of positions therebetween. Moving backrest member  54  to the flat position as shown in FIG. 1 is accomplished by depressing release  84  and exerting a counter force against the biasing force of the biasing spring  83 . Once the backrest member  54  is back in the flat position, releasing release  84  will lock the backrest panel in the flat position. 
     Leg segment  62  includes a pair of side members  63 , and each connected at an upper end thereof to front ends of the pair of the base members  42 , such as at third pivot points  93 . A foot support panel  64  is positioned between the pair of side members  63 , near respective lower ends thereof, and is pivotably connected thereto, such as at fourth pivot points  94 . A secondary retractable footrest  61  pivotally mounted to the pair of side members  63  is also provided which can be elevated and secured in place by a pair of locking arms  67 , illustrated in FIG. 2, to provide a footrest to a reclined patient and to act as a pull handle. The footrest  61  is stowed flush against the side members  63  as illustrated in FIG.  1 . 
     Seat segment  72  is positioned between the pair of base members  42  and is pivotably connected at a rear end thereof to the hinged end  54   b  of backrest member  54 , such as at second pivot points  92 . A front end of the seat segment  72  is connected to a rear end of the foot support panel  64  of the leg segment  62  by a leg support panel  65 , which is pivotably connected at a first end thereof to the seat segment  72 , such as at fifth pivot point  95 , and which is pivotably connected at a second end thereof to the rear end of the foot support panel  64 , such as at sixth pivot point  96 . 
     Each one of a pair of linkage brackets  74  is fixedly secured to its respective side member  63  of leg segment  62  and is connected to one of the pair of side rails  53  of back segment  52  by a respective linkage bar  76 . More particularly, a first end of each linkage bar  76  is pivotably connected to its respective linkage bracket  74  and a second end of each linkage bar  76  is pivotably connected to its respective side rail  53 . Accordingly, a four-bar linkage system is defined consisting of linkage bars  76 , side members  63 , base members  42  and side rails  53 , having pivotably, pinned connections with one degree of relative movement between adjacent links. 
     Linkage bars  76  connect back segment  52  with leg segment  62  such that as back segment  52  is pivoted about first pivot point  92  in the direction shown generally as moment arrow “M” (FIG.  1 ), foot support panel  64 , leg support panel  65 , seat segment  72  and backrest member  54  move into a generally planar alignment or inclined, fully-reclined position as shown particularly in FIG. 2, such that a patient situated thereon assumes a generally supine position. It is to be appreciated that during this movement the brackets  56  pivot about cross- member  55  above legs  57  thereby effecting a vertical lifting of side rails  53 . This vertical lifting of the side rails  53  above legs  57  raise the attached wheels  81  to an elevation sufficient to roll the loading end of the cot  10  onto a high transport deck, indicated by dashed line  99  in FIG. 2, of an ambulance. Accordingly, bracket  56  and legs  57  together extend wheels  81  at least 30 inches and more preferably, 33 inches above a loading surface  100 . 
     Two lockable extending members or lift biasing springs  85  are each pivotably connected to, and thereby connect, one of the pair of linkage bars  76  with one of the pair of side rails  53 . The pair of lift biasing springs  85  is constructed in a similar fashion as biasing spring  83  described above. It is to be appreciated that using the pair of lift biasing springs  85  reduces weight and part count while improving ergonomics and function. The use of lift biasing springs  85  allow infinite adjustment and part reduction over the prior art six-position ratchet bar style locking and positioning mechanisms, such as provided in U.S. Pat. No. 3,289,219 to Ferneau et al. Preferably, the pair of lift biasing springs  85  are model 6465KM0400N 103/98 gas springs manufactured by Stabilus under the trademark BLOC-O-LIFT, and provide up to 400 newtons of tensile biasing force when a locking mechanism provided therein is released. Release arm  84   a  is operatively connected to and activates release mechanisms within lift biasing springs  85 , as described hereinabove with respect to springs  83 . Lift biasing springs  85  assist relative movement of linkage bars  76  relative to side rails  53  to increase the angle therebetween, thereby smoothly urging the bed frame  50  from the chair position shown in FIG. 1 to the fully-reclined position shown in FIG. 2 or to any other infinite number of positions therebetween without jarring the patient carried thereon. 
     Backrest member  54  includes a substantially planar backrest panel  58  for supporting the patient situated thereon and a second cross-member  59  to support the backrest panel  58 . Provided through panel  58  are one or more slotted, openings  58   a  near the cross-member  59 , such that a restraining strap (not shown) used to restrain the patient against the cot  10  can pass through the opening  58   a , front-to-back, and tied around the cross-member  59 . As such, cross-member  59  is preferably spaced away from panel  58 . Additionally, pillows, pads or cushions may be secured to foot support panel  64 , foot support panel  65 , seat segment  72  and backrest member  54 , and any combination thereof, to provide a comfortable resting place upon which the patient is situated. 
     Although the present invention has been described in terms of a specific embodiment which is set forth in detail, it should be understood that this is by illustration only and that the present invention is not necessarily limited thereto, since alternative embodiments not described in detail herein will become apparent to those skilled in the art in view of the above description, the attached drawings and the appended claims. Accordingly, modifications are contemplated which can be made without departing from either the spirit or the scope of the present invention.