Patent Publication Number: US-6701545-B1

Title: Multiple level roll-in cot

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to ambulance cots and more particularly with improvements to multi-level roll-in cots capable of being used in different types of emergency vehicles having cot-receiving floors. 
     Ambulance cots typically comprise an essentially rectangular patient support frame with wheeled collapsible-leg assemblies enabling the stretcher to be stowed or loaded into the back of an ambulance. Examples of such prior art cots are disclosed in U.S. Pat. Nos. 4,097,941, 4,192,541, 4,767,148, 5,537,700, and 5,575,026. Although the prior art cots have been generally adequate for their intended purposes, they have not been satisfactory in all aspects. Such ambulance cots are not always suited to accommodate the medical needs of persons with large bodies. Often it is difficult to place a large-bodied patient in such conventional cots, and sometimes these cots cannot accommodate such large-bodied persons at all. In those situations, a portable stretcher is typically placed on top of such an ambulance cot in an unsecured or jerry-rigged fashion. However, for obvious reasons the lack of a means to safely and securely transport such large-bodied patient on these conventional cots can degrade the quality of medical care provided to them. 
     Once such a large-body patient is loaded into the cot, the disproportionate size of the patient and the compact nature of both conventional stretchers and ambulance cots often provide little extra space for emergency equipment, such as oxygen tanks, intravenous medications, cardio monitors and the like which are required for immediate treatment. These devices are often placed on the empty spaces of the cot&#39;s mattress without compromising the patient carried thereon. However, with such a large-bodied patient, the lack of available mattress space can lead to distractions to the emergency attendants, clutter in the transport vehicle, and general difficulty during transportation of the patient. 
     Further, the compact nature of such conventional ambulance cot provides little extra side rail surfaces by which extra attendants can grip and lift such cots into the transport deck of an emergency vehicle when carrying such a large-body patient. This lack of convenient handling/gripping surfaces therefore requires the attendants to either compromise the normal handling/gripping surfaces or find an available side-rail surface in order to increase the number of attendants lifting the cot. As a result, the attendants are often unevenly distributed or bunched up around the cot placing strain and unnecessary stress on the attendants because of the often, uneven handling/lifting of the cot. Strains and stresses are also placed on the patient as well as the stretcher undercarriage by this uneven handling/lifting of the cot during loading. Accordingly, there remains a need in the art for an ambulance cot arrangement which alleviates or at least ameliorates such difficulties. 
     SUMMARY OF THE INVENTION 
     The present invention alleviates or at least ameliorates the above-mentioned difficulties by providing a simple arrangement that conveniently provides additional side handling/lifting surfaces to a cot construction. Cot constructions of the present invention include a cot frame supported by a stable undercarriage, which permit the cot frame to be raised and lowered to a plurality of positions of use. The cot frame may be provided with integral patient support features, such as positionable back, leg, and side arm supports, or may be provided with a removable patient support structure which is detachably secured to the cot frame. Where a removable patient support structure or top is provided, the cot frame is provided with locking mechanism, which automatically locks the removable top to the cot frame when the top is seated on the frame, readily, accessible release means being provided to permit rapid detachment of the top from the cot frame. 
     In order to expand the handling/lifting ability of attendants around the cot frame, at least one transverse cot frame member slidable houses a pair of side-arm extensions according to the present invention. Such an arrangement provides the cot constructions of the present invention with extra side handling/lift surfaces without compromising the existing handling/lifting surfaces. Accordingly, the cot constructions may be loading directly into an emergency vehicle in a controlled and more-evenly spaced fashion when carrying a large-bodied patient thereon, thereby reducing the stress adds strain on the attendants, the patient, and the cot frame. 
     In one embodiment of the present invention, an elevating cot adapted to be rolled into emergency vehicles is disclosed. The cot comprises a generally rectangular cot frame having a leading end and a trailing end, and a pair of side extension arms provided to the cot frame between the leading end and the trailing end. Each of the side extension arms is adapted to slidably extend outwardly from a stowed position adjacent the cot frame to an extended position substantially perpendicular to the cot frame. 
     In another embodiment of the present invention, an elevating cot adapted to be rolled into emergency vehicles is disclosed. The cot comprises a generally rectangular undercarriage having wheels, a generally rectangular cot frame having a leading end and a trailing end, leg members interconnecting the cot frame and the undercarriage, and a latching device adapted to selectively secure the leg members in a plurality of elevational positions. A pair of side extension arms is provided to the cot frame between the leading end and the trailing end. Each of the side extension arms is adapted to slidably extend outwardly from a stowed position adjacent the cot frame to an extended position substantially perpendicular to the cot frame. 
     In still another embodiment of the present invention, an elevating cot adapted to be rolled into emergency vehicles is disclosed. The cot comprises a generally rectangular undercarriage having a leading end and a trailing end, wheels affixed to the undercarriage, and a generally rectangular cot frame overlying the undercarriage. The cot frame has a leading end and a trailing end. Co-acting pairs of complementary cross-forming frame members extend between and interconnect the cot frame and the undercarriage. Each of the pairs of frame members comprises a first frame member of fixed length and a second frame member having an extensible section at its lowermost end. A latching device is adapted to selectively secure the cross-forming members in a plurality of elevational positions. A pair of side extension arms is provided to the cot frame between the leading end and the trailing end, each of the side extension arms is adapted to slidably extend outwardly from a stowed position adjacent the cot frame to an extended position substantially perpendicular to the cot frame. 
     These and other features and advantages of the invention will be more fully understood from the following description of some embodiments of the invention taken together with the accompanying drawings. It is noted that the scope of the claims is defined by the recitations therein, and not by the specific discussion of features and advantages set forth in the present description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limitation in the accompanying figures, in which like references indicate similar elements, and in which: 
     FIGS. 1 a  and  1   b  are side views of a cot structure embodiment of the invention having an integral top, with parts in dotted lines for purposes of illustration; 
     FIG. 2 a  is a top plan view of the embodiment of FIG. 1, with parts broken away to show underlying parts; 
     FIG. 2 b  is an enlarged fragmented perspective view of a portion of the embodiment of FIG. 2 a,  with parts removed to show underlying parts; 
     FIG. 3 is a side view of another cot structure embodiment of the invention adapted to receive a removable stretcher top; 
     FIG. 4 is an elevational perspective view of another cot structure embodiment of the invention, with parts removed for purposes of illustration; 
     FIG. 5 is an elevational perspective view of another cot structure embodiment of the invention having a stretcher top; and 
     FIG. 6 is a top view of another cot structure embodiment of the invention, with parts in dotted lines for purposes of illustration; 
    
    
     Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiment(s) of the present invention. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIGS. 1 a,    1   b,    2   a,  and  2   b,  illustrated is a cot structure embodiment of the invention having an integral top structure, with parts broken away and others in dotted lines for purposes of illustration. The cot is indicated generally at  100 , and has a rectangular undercarriage  1  mounting pairs of caster wheels  2  at its opposite ends. The undercarriage  1  includes opposing side frame members  3  and  4 , which are interconnected by transverse frame members  5  and  6 , the latter being best seen in FIG.  2 . 
     Extending upwardly from the undercarriage  1  are pairs of cross forming frame members  7 ,  8  and  7   a,    8   a,  which serve to interconnect the undercarriage  1  with a cot frame  9 . Cot frame  9  includes opposing tubular side frame members  10  and  11  interconnected at the foot or trailing end by a transverse tubular end member  12 . At their leading or forward ends, the side rails  10  and  11  each terminate at a respective hinge pivot  14 . As best seen by FIG. 2 b,  supported between the pair of hinge pivots  14  is a transverse frame  13  having a drop frame  15  rotatably coupled thereto. Drop frame  15  includes tubular side frame portions  16  and  17  joined at their forward ends by an end frame member  18  (FIG. 2 a ). 
     The drop frame  15  is releasable engaged by the pair of hinge pivots  14 , which also limits the range of motion of drop frame  15 . In particular, rotation of drop frame  15  is arrested by latch mechanism  19 , which is best seen in FIG. 2 b.  Latch mechanism  19  permits the drop frame  15  to be moved from the extended position, as seen in FIGS. 1 and 2, to a middle position, which is shown in dotted lines in FIG. 1 b,  or to a collapsed position also shown in FIG. 1 b.    
     The drop frame  15  is locked either in the extended position or middle position by a spring biased latch  20  engaging a respective one of slots  99  provided in each pivot hinge  14 . A release handle  21  provided to the drop frame  15  releases the sliding latch  20  from the engaged slot  99 , such that the drop frame  15  may be repositioned. It is to be appreciated that positioning the drop frame  15  in the middle position provides a lower lifting handle position for improved ergonomics. 
     The drop frame  15  is provided with a pair of loading wheels  22  projecting downwardly from the outermost ends of side frame sections  16  and  17 . The wheels  22  are interconnected by a rod  23  mounting a generally U-shaped tubular bail  24 , which is spring biased to the downwardly extending position seen in FIGS. 1 a  and  1   b.  The tubular bail  24  is biased by springs  25 , and is adapted to engage a tongue-like floor fitting  26  mounted on the floor of the emergency vehicle. The bail  24  also may be deflected upwardly by a release arm  27  positioned adjacent both sides of the cot frame, which permits the attendant to release the bail  24  from engagement with the floor fitting  26  when it is desired to remove the cot from the vehicle. 
     It will be understood that the basic cot frame  9  may be provided with various adjustable features, such as folding side arms  28 , a multiple-position backrest, indicated generally at  29 , and an adjustable leg section for placing the patient in a shock position, indicated generally at  30 , all of which are conventional features. As best seen by FIG. 2 a,  the backrest  29  has a generally u-shaped frame member  31  hingedly connected at its ends to a traverse frame member  126  (FIG. 2 a ), respectively, by means of pivot fittings  32 . The backrest  29  is movable from a reclined position shown in FIG. 1 a,  to an upright position illustrated in FIG. 1 b.    
     The backrest  29  is assisted from the reclined position to the upright position, and a plurality of positions therebetween indicated by the arrow line in FIGS. 1 a  and  1   b,  by a lifting device  33 . The lifting device  33  is pivotally attached at an upper end  34  to a set of mounts  35 . Mounts  35  are attached to the patient surface and the backrest frame  31  end position. Preferably, the lifting device  33  is a gas-assisted cylinder or alternatively, either a hydraulically or a mechanically assisted cylinder. In the illustrated embodiment of FIG. 1 b,  manipulation of a lever  36 , also provided at the upper end of the lifting device  33 , causes gas-assisted cylinder  37  to raise or lower the backrest  29  as desired. That is, depressing or raising the lever  36  operates a detent on the gas-assisted cylinder  37 , which releases a locking mechanism internally on the cylinder and permits movement of the backrest  29 . When the lever  36  is released, it moves back to a centered, at rest, position permitting a detent (not shown) on the cylinder to rise, locking the backrest  29  in place. The lower end of the lifting device  33  is connected to the cot frame  9  by a rotatable mount (not shown) so that it may rotate downward as it retracts permitting the backrest  29  to be placed in the reclined position. 
     The adjustable leg section  30  is formed by u-shaped frame members  41  (partially shown in FIG. 2) hingedly connected at its ends to a transverse hollow tubular member  42  by hinge members  43 , as seen in FIG.  2 . At the opposed end of the frame member  41 , a footrest  44  is mounted. The footrest  44  is adapted to be raised and lowered by latch members  46  of known construction. Other features also may be provided, such as an auxiliary bail-like end frame member  40  underlying end frame member  12 , which is positioned to be easily grasped by an attendant. 
     Referring to FIGS. 1 a  and  1   b,  the pairs of cross-forming frame members  7 ,  8  and  7   a,    8   a  are pivotally connected by a pivot rod  47  at the point of intersection of the pairs of cross-formning frame members  7 ,  8  and  7   a,    8   a.  In addition, the cross-forming frame members  8  and  8   a  telescopically receive tubular extensions  48  and  48   a  at their lowermost ends, which are pivotally connected to the transverse frame member  5  by fittings  49  and  49   a,  respectively. At their uppermost ends the cross-forming frame members  8  and  8   a  mount fittings  50  having guide pins  51  slidably received in elongated guide members  52  each provided with an elongated pin receiving slot  53 . 
     As best shown by FIG. 4, which has the same undercarriage arrangement of the embodiment of FIGS. 1 a  and  1   b,  pins  51  are interconnected to a latching device  65  adapted to selectively secure the cross-forming frame members  8  and  8   a  in a number of elevational positions. The latching device  65  is formed of a stabilizer  54  and locking bar  56 . The stabilizer  54  includes a hollow passageway  55  that loosely receives the elongated locking bar  56 . The locking bar  56  is connected at one end to a yoke  57  pivotally mounted on the transverse frame member  13 . The locking bar  56  twists through substantially 90° intermediate its ends to provide a vertically disposed portion in engagement with the yoke  57  and a horizontally disposed portion extending through the passageway  55  in stabilizer  54 . The passageway  55  has a latch pin  58  extending vertically therethrough for selective engagement with a series of notches or teeth  59  formed in the locking bar  56 . A spring  60  is positioned to urge the notches in the locking bar into engagement with the pin. The locking bar  56  may be displaced laterally by means of loop-like release members  61  and  62 , which are positioned to be grasped by the cot attendant either at the forward end of the cot or along one side thereof. 
     The lowermost ends of the cross-forming frame members  7  and  7   a  are pivotally connected to transverse frame member  6  of the undercarriage  1  by fittings  63 . At their uppermost ends, the cross-forming frame members  7  and  7   a  are pivotally connected to the transverse frame member  13  of the cot frame by fittings  63   a.  The cross-forming frame members  7  and  7   a  may be reinforced intermediate their ends by sleeves  64 , as seen in FIG. 3, an embodiment having substantially the same undercarriage arrangement of FIGS. 1 a  and  1   b.    
     With latching device  65 , the cot frame  9  of the various embodiments of the invention may be selectively secured in a plurality of elevational positions or collapsed against the undercarriage  1 . This is accomplished by releasing the locking bar  56  and permitting the cross-forming frame members  8  and  8   a  to move to the outermost ends of the slots  53  in the elongated brackets  52 . At the same time, extensible sections  48  and  48   a  telescope within the lowermost ends of cross-forming members  8  and  8   a.  As the cot  100  is elevated, the sets of cross-forming frame members  7  and  7   a  will elevate the cot frame relative to the undercarriage  1  in a generally horizontal plane. However, as the fully elevated positions of the cot frame are approached, e.g., such as the two innermost notches on the locking bar  56 , the cot frame  9  will be inclined upwardly at its leading end, as illustrated in FIGS. 1 a,    1   b,    3 , and  4 . This upward inclination occurs due to the extensible cross-forming frame members  48  and  48   a,  and the relation of the pivot rod  47  to the points of intersection of the pairs of frame members  7 ,  8  and  7   a,    8   a.  This upwardly inclined position elevates the loading wheels  22  to a higher position than if the cot frame remained horizontal and permitting the transfer of the cot into an emergency vehicle having an unusually high floor level. 
     Referring now to FIG. 3, illustrated is another cot structure embodiment of the invention having no top patient supporting structure, with parts broken away and others in dotted lines for purposes of illustration. Since many of the features of the embodiment of FIG. 3 are similar to those discussed in reference to FIGS. 1 la,    1   b,    2   a,  and  2   b,  only the differences will be discuss for brevity, in which like symbols indicate similar elements. In the illustrated embodiment of FIG. 3, the cot frame  9  is adapted to receive a removable top  38 , such as a stretcher/chair stair illustrated in commonly assigned U.S. Pat. No. 4,767,148, which is herein fully incorporated by reference. 
     As shown in FIG. 3, the cot frame  9  is provided with leading and trailing sets of seats, indicated generally by  67  and  68 , respectively. Seats  67  and  68  are adapted to receive correspondingly positioned frame members (not shown) of the removable top  38 . It will be understood that the removable top  38 , irrespective of whether it is a simple stretcher, a stretcher/stair chair or other form of cot, will be provided with opposing longitudinal frame members arranged to be seated on and secured to the sets of seats  67  and  68  of the cot frame. Seats  67  and  68  comprise horizontally disposed pairs of supporting plates (not shown), having a pair of vertically disposed brackets  71  and  72 . Brackets  71  each have a C-shaped slot  73  therein. Brackets  72  also each have a C-shaped slot  74 , but in this instance they are preceded by inclined cam rails  75  which serves to lock transversely extending frame members of the removable top  38  in the slots  74  until they are lifted from the slots, permitting the removable top  38  to be separated from the cot frame  9 . 
     In the embodiment of FIG. 1, the backrest  29 , as well as the remaining upper surface of frame  9  in this embodiment is covered with a support surface covering for accommodating a support mattress and/or a patient, which is illustrated by  201  in FIG.  2 . For the embodiment of FIG. 3, the support surface covering may be optional as cot frame  9  is adapted to removably attach the conventional removable stretcher. 
     Turning now to other features of the present invention, as best illustrated by FIGS. 2 a,    4 ,  5 , and providable to any of the foregoing cot constructions, a pair of side extension arms  102  and  102   a  is shown. Side extension arms  102  and  102   a  are slidable housed within an interior cavity of the transverse tubular member  42  (FIG.  4 ). Each of the arms  102  and  102   a  may be extended from a stowed position as illustrated by side extension arm  102   a,  outwardly from the cot frame  9  to an extended position, as illustrated in FIG. 2 a  by side extension arm  102 . The side extension arms  102  and  102   a  when extended are substantial perpendicular to its respective side frame member  10  and  11  between the foot and trailing ends of the cot frame  9 . In the extended and stowed positions, the side extension arms  102  and  102   a  are maintained so positioned by releasable securing methods, such as detents, spring biasing, locking pins, chocking collars, and the like. 
     Additionally, in another embodiment, each of side extension arms  102  and  102   a  may be provided with a pull out position, which exposes a hinge member  111 , as illustrated by FIG.  5 . The hinge member  111  of each side extension arms  102  and  102   a  is normally accommodated within the tubular member  42 . However, when slidable exposed by fully extending a side extension arm, for example,  102  to the pull out position, hinge member  111  permits arm  102  to be folded 90° from its substantially horizontal extended position illustrated by arm  102   a.  In this folded position, side extension arm  102   a  may be rotated thereabout as illustrated. 
     In the stowed position, the side extension arms  102  and  102   a  provide a small profile in order to be unobtrusive to attendants working around the cot frame  9 . In the extended position, the side extension arms  102  and  102   a  provide a convenient handling surface for attendants to situate themselves around the cot frame  9  in order to control the movement and lifting of the undercarriage into an emergency vehicle. It is to be appreciated that these side extension arms  102  and  102   a  provide the cot frame  9  with added handling points by which extra attendants may help to lift a large body person situated on the cot frame to and from the emergency vehicle. 
     Referring back to FIG. 1 b,  it is to be appreciated that each of the folding side arms  28  and  28   a  is rotatably connected to the cot frame  9  by a respective pair of side arm mounts  101  and  101   a.  The side arm mounts  101  and  101   a  are mounted to their respective longitudinal side frame member  10  or  11 . The side arms  28  and  28   a  each rotates about their respective longitudinal side frame members  10  and  11 , thereby providing 180° rotational freedom from a vertically-up position, as illustrated, to a vertically-down position illustrated by the dotted lines in FIG. 1 b.  A side-arm release  103  is provided to each of the side arm mounts  101  and  101   a.  With reference to FIG. 6, when a technician pulls the side-arm release, spring biased holding pins (not shown) are lifted from a set of recess in the latch block  105  and  105   a  mounted at the end portion of the respective folding side arm that is rotatably mounted to the side frame member. It is to be appreciated that with the set of recesses, the folding side arms may be releasably positioned substantially horizontal to the cot frame  9  or approximately 90° from vertical. 
     Each folding side arm  28  and  28   a  may be positioned above or below their respective side extension arm  102  and  102   a.  Situating the folding side arms  28  and  28   a  below their respective side extension arms, as illustrated by  102 , the folding side arms are structural reinforced by the side extension arms such that two or more attendants may use the folding side arms as a lifting surface. Such a lifting configuration is useful in situations when handling a person of an extreme amount of weight (i.e., greater than 300 lbs). Situating the folding side arms  28  and  28   a  above their respective side extension arms, as illustrated by  102   a  by dotted line, the folding side arms are provided with structural support. Such a supporting configuration is useful to increase the support surface area of the cot support surface to accommodate person requiring additional cot space (i.e., obesity). Further, the supporting configuration is useful if necessary to hang emergency equipment/medical devices, and/or personal belongs of the victim. 
     Referring to FIG. 6, illustrating other embodiments of the invention, if desires, one or both side arm supports  28  and  28   a  may be provided with an additional support surface covering  201   a.  Moreover, the end cap portion  104  of each side extension arm  102  and  102   a  may be shaped in a number of various configurations, which are illustrated in FIG. 2 a  as for example and not to be limited by, dotted lines  106 ,  108 ,  110 , and  112 . As shown, provided is a plug-end or doughnut-shaped portion  104 , a T-shaped end portion  106 , a mushroom shaped end portion  108 , an angled-bracket end portion  110 , and a U-shaped or umbrella handle end portion  112 , each of the various end cap portion configurations providing their own unique advantages. 
     As illustrated by FIG. 6, a pair of double-sided extension arms may be provided to the cot frame  9 , which are illustrated by dotted lines  114  and  114   a.  In this configuration, an additional transverse hollow tubular member  42   a  is included in the cot construction, wherein the pair of transverse members  42  and  42   a  slidably house within their interior cavity the arm portions  116  of each double-sided extension arm  114  and  114   a.  As also illustrated, the arm portions  116  of each double-sided extension arms extend substantially perpendicular to its respective side frame members  3  and  4 . In the stowed position, a handle portion  118  being the portion which spans between the arm portions  116  of the double side extension  114 , is situated adjacent its respective side frame member  3  or  4 , substantial flush, thereby providing a unobtrusive profile. 
     Further, to provide the above described cot construction embodiments with an increased load bearing capacity, a central strength member  120  is provided to the cot frame  9 . Preferably, the central strength member  120  is an I-beam construction. The transverse members of the cot frame  9  such as, for example, frame member  13 , transverse members  42  and  42   a,  and additional traverse frame members  122 ,  124 , and  126  are mounted (e.g., bolted, welded, etc.) to the central strength member  120 . It is to be appreciated that centrally supporting and/or connecting these transverse members to the strength member  120  permits increased load bearing of the cot  100  by distributing more evenly the weight throughout the cot frame  9 . Accordingly, the cot  100  of the present invention is capable of supporting loads upon the cot frame up to about 600 lbs. 
     In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. Any modification of the present invention which comes within the spirit and scope of the following claims should be considered part of the present invention.