Abstract:
A litter tie-down apparatus is provided for quickly and easily securing a litter safely and securely in a transporting vehicle, the apparatus having a main body strap member arranged to engage the lift handles of a litter, the strap member mounting a pair of adjustable-length securement strap members arranged for connection to a securement fixture in a vehicle, and a ratchet winder assembly is provided to shorten at least one of the securement strap members and thereby tension the apparatus and litter against movement in the vehicle. A quick release arrangement selectively operates to immediately loosen the securement straps and allow the main body member to be slided off of the lift handles of the litter for emergency evacuation of the litter and patient from the vehicle.

Description:
This application claims benefit under 35 U.S.C. 119(e) of the priority filing of U.S. Provisional application Ser. No. 60/812,334, Filed 8 Jun. 2006. 

   BACKGROUND OF THE INVENTION 
   This invention relates to litters used in the emergency transport of soldiers and other injured persons in field situations and more particularly to a litter tie-down apparatus to safely and effectively secure a patient-supporting litter in place in a vehicle to prevent from the litter from movement, rearward, laterally or vertically during operation of the vehicle in transporting the patient to a medical facility or other safe location. 
   Litters are well known patient transport devices particularly in field situations such as military battlefields and such, and typically comprise a pair of longitudinally elongated, laterally spaced apart poles which terminate in opposite end lifting handles, a sheet of flexible fabric material being secured in spanning condition between the pair of poles to form a bed-like surface upon which a patient is lain and strapped down. A pair of tending personnel, one disposed at each end of the litter, may then grasp the lifting handles and lift and carry the litter and reclined patient to a rescue aircraft or ground vehicle wherein the litter is secured in place prior to transport to a medical facility. 
   As will be appreciated by those skilled in the art, it is critical that the patient-supporting litter be positively secured in the vehicle against any free movement that may result during operation of the vehicle and cause the litter to slide about or worse, tip over, tumble or otherwise become displaced with potential further injury to the already-injured patient. As will be recognized, travel in a ground vehicle in battlefield terrain can be extremely rough and precarious and travel in an aircraft is also a rough and turbulent ride at times. 
   Accordingly it is a well known practice to tie or otherwise secure litters down in vehicles in order to secure them against undesirable movements due to the vehicle&#39;s motions. However, while the releasable securement of litters is clearly an important aspect in the vehicle transport of litter-born patients, it is also essential that the litter be able to be quickly released from its securement in the event of accident, fire or other need for emergency evacuation from the vehicle. To this end, military requirements and regulations provide that a litter, when secured in the vehicle, must be able to be freed of its tied down securement in the vehicle within 30 seconds time, to assure for timely emergency evacuation of the litter and its occupant in the event of urgent need, such as fire, explosion, crash or other occurrence requiring immediate emergency evacuation of the vehicle. 
   The present invention provides a litter tie-down apparatus that is specifically arranged to provide for quick and simplified positive securement of a litter in place in a vehicle, and also is arranged to permit quick release and disconnection from the litter whereby the litter is completely freed in very short order for facilitated emergency evacuation of the litter and its occupant from the vehicle. 
   SUMMARY OF THE INVENTION 
   In its basic concept, this invention provides a litter tie-down apparatus having a laterally elongated main body strap member arranged with opposite end loops for engaging the lift handles of a litter, the main strap member mounting a ratchet winder assembly which in turn mounts a pair of opposite securement strap members provided at their outer ends for connection to a pair of securement mount fixtures on the vehicle, the ratchet winder assembly operable to wind up at least one of the securement strap members to tighten the litter against its underlying support, the ratchet winder assembly including a quick release mechanism operable to quickly loosen the securement straps to permit the main body strap member to be quickly slid off the litter lift handles to quickly free the litter for evacuation from the vehicle. 
   It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, the provision of a litter tie-down apparatus that facilitates both securement and urgent disconnection of a litter within a vehicle, thereby overcoming the disadvantages and limitations of litter securement devices provided heretofore. 
   Another object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which utilizes a fabric main body strap member and fabric securement strap members for permitting the tie-down apparatus to be collapsed into a small, storage condition for facilitated storage when not in use. 
   Another object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which requires no adjustment of the length of the main body strap member for engagement with the lifting handles of conventional litters. 
   Another object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is arranged for alternative securement to a securement mount fixture in a vehicle by carabiner or other suitable fastener apparatus interengaging the securement strap members and available securement mount vehicles on a vehicle. 
   Yet another object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is arranged to provide for release from litter-securing condition and separation from a litter in an amount of time well within the time limitations required by military regulation governing emergency evacuation requirements for litters from vehicles. 
   A further object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is arranged to be released from a litter being supported simply by loosening the securement strap members and sliding the main body strap member off of the lifting handles of the litter without need of disconnection of the tie-down apparatus from the mount fixtures of the vehicle. 
   A further object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is arranged to adjustably accommodate connection to available mounting fixtures in a vehicle disposed at different heights and positions relative to a litter being secured. 
   A still further object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is arranged to provide simplified, non-complicated installation of the tie-down apparatus and simple, non complicated release and disconnection of the tie-down apparatus to reduce training requirements and facilitate easy, straightforward use and operation of the apparatus especially in emergency situations in which safety to both patient and tending personnel requires expediency. 
   A still further object and advantage of the present invention is the provision of a litter tie-down apparatus of the class described which is of simplified construction for economical manufacture and reliability in use. 
   The foregoing and other objects and advantages of the present invention will appear from the following detailed description, taken in connection with the accompanying drawings of a preferred embodiment. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a foreshortened, top perspective view of a litter being secured in a vehicle by a pair of tie-down strap members embodying features of the present invention. 
       FIG. 2  is a top perspective view on an enlarged scale of the litter tie-down apparatus of  FIG. 1  showing the construction in closer detail. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A litter tie-down apparatus embodying features of the present invention is illustrated in  FIGS. 1 and 2  of the drawings. Although the apparatus is being shown in a preferred form herein, it is to be understood that the particular structural arrangements shown are illustrative of arrangements suitable for the purpose, and that other suitable arrangements may be provided as alternatives if so desired or needed for the particular purpose. 
     FIG. 1  is a foreshortened perspective view illustrating a typical litter L which as is well known, includes lifting handles L′, L″ projecting from each longitudinal end of the litter.  FIG. 1  shows the litter tie-down apparatus  10  of this invention engaging the lifting handles at the opposite ends of a litter as will be explained. 
   As seen in  FIGS. 1 and 2 , the tie-down apparatus includes a main body strap member  12  arranged to mount or terminate in end loop members  14  arranged to receive therethrough the lifting handles L′, L″ as seen in  FIG. 1  of the drawings. Although in its preferred form the strap member is formed of heavy duty, reinforced fabric material in which the end loops  14  are formed by overlapping and stitching of the material, the main body strap member  12  may if desired be alternatively formed of rigid material such as synthetic thermoplastic resin material formed with loops  14  as will be apparent. 
   As shown, the main body strap member  12  supports a ratchet assembly  16  engaging on its winder drum  16 ′ a first securement strap member  18  having a preselected overall length sufficient to extend from the ratchet winder mechanism to a securement fixture M mounted in a vehicle (not shown) as will be apparent in  FIG. 1 . The outer, free terminal end of the first securement strap member  18  mounts a selected fastener member  20  such as snap hook  20  illustrated. The strap member  18  may if desired also include a loop  22  formed at the terminal end mounting the fastener member  20  in order to receive an alternate fastener member, such as a carabiner (not shown) for alternative connection of the strap end portion to a securement fixture on a vehicle if so needed or desired. The first securement strap member  18  is slidably retained against the main body strap member  12  as by a strap confinement loop  24  secured on the main body strap member  12  adjacent the loop member  14 . 
   As seen best in  FIG. 2 , the base portion of the ratchet winding mechanism  16  fixedly mounts the end of a strap member  26  which in turn mounts at its opposite outer terminal end an adjustable buckle mount member  28  which in turn receives and adjustably secures an end portion of a second securement strap member  30  which is arranged to extend from the opposite end of the main body strap member. The strap member  30  is slidably retained against the main strap member by a strap confinement loop member  32  similar to the loop member  24  previously described. As seen best in  FIG. 2 , the outer terminal end of second securement strap member  30  also mounts a connector member  20  arranged for connection to a securement mount fixture M in a vehicle as described in connection with first securement strap member  18 . Similarly, the outer end portion of the second securement strap member  30  may also include a loop member  22  for an alternate connector such as a carabiner if so desired. 
   Preferably means is provided to retain the ratchet winder assembly  16  in position disposed substantially centrally on the strap member  12  between the opposite loops  14  adjacent its longitudinal terminal ends. In the embodiment illustrated, confining loop members  34  are secured on the main body strap member  12 , one on each side of the ratchet assembly  16  and arranged to freely overlie the corresponding straps  18 ,  26 , whereby to prevent longitudinal movement of the ratchet assembly on the main body strap member  12  by abutment with one strap  34  or the other caused by tension or pulling movement on the respective securement straps  18 ,  30  as will be appreciated. These confining loop members  34  also prevent displacement of the ratchet mechanism  16  during ratcheting operation to wind the securement strap  18  onto the winding drum  16 ′ as is known in these devices. As seen in  FIG. 2 , the confining loop members may if desired be provided as lengths of strap material secured to the base body strap member  12  and arranged to be wrapped over and around the straps and body member and be releasably secured in place as by corresponding first  36  and second  36 ′ components of a conventional hook and loop type fastener arrangement. 
   Referring briefly again to the strap winding ratchet mechanism  16 , the apparatus includes a ratchet-operating handle member  36  arranged to engage the winding drum through a ratchet assembly whereby operation of the ratchet handle member effects indexed rotation of the drum  16 ′ in a direction to wind the strap  18  onto the drum. The ratchet arrangement, as is well understood in these devices, prevents undesired, reverse rotation of the drum member with consequent unwinding of the strap member. The ratchet strap winding mechanism also includes a release mechanism  38  which is operable, when pulled upon, to disengage the ratchet connection to allow free, reverse rotation of the winding drum when so desired. In the embodiment illustrated, the release member  38  of the ratchet is engaged by a release strap member  40  arranged with a loop section configured to engage the release member  38  and capture within its interior the handle member  36  as seen clearly in  FIG. 2 . By grasping the release strap member  40  and pulling upon it towards the right in  FIG. 2 , the release member  38  is pulled to disengage the ratchet system and free the drum member to permit unwinding of the strap  18  wound thereabout. 
   From the foregoing, reference is now primarily directed to  FIG. 1  of the drawings wherein it will be understood that a litter L, which would in these circumstances have an injured person secured on it, is positioned in a designated position in a transport vehicle. The litter tie-down apparatus is installed onto the litter by passing the litter handles L′, L″ through the corresponding loops  14  at the ends of the main body strap member  12 . The free end of the strap member  30  is then directed to a designated securement fixture M on a vehicle and engaged therewith by the connector member  20  or other securement fixture if provided through loop  22 . The length of the strap member  30  is then adjusted to snug the strap by adjusting the length of the strap  30  through the strap adjustment buckle member  28  as is apparent in  FIG. 2 . It should be mentioned that once this length has been established for a given vehicle, this adjustment of the strap  30  will likely not have to be done again in subsequent operations when that vehicle is used. 
   The other securement strap member  18  is extended to a corresponding securement fixture M on the vehicle and connected thereto as by the end connector member  20  or carabiner type arrangement described hereinbefore. With the opposite terminal ends of the strap members  18 ,  30  thus secured to fixed mounts M on the vehicle, the handle of the ratchet member is grasped and operated to wind the opposite end length of the strap  18  onto the winder drum  16 ′ until the assembly is tightened sufficiently to positively secure the end of the litter against movement. The opposite longitudinal end of the litter is then secured by a second litter tie-down apparatus  10  as will be apparent. The litter is thus tensionably secured positively and safely in designated position in the vehicle for operation of the vehicle to transport the injured person for medical attention at a facility. 
   As is well understood in the military, military requirements and regulations provide that litters, when secured in vehicles, must be freed from their tie-down support within 30 seconds for emergency evacuation of the litter and its occupant from a vehicle in the event of urgent need, such as a fire, explosion or other occurrence requiring the urgent evacuation of the vehicle. In this regard, to release the litter from its secured condition, a person need only grab the release strap member  40  and pull on it outwardly and then upwardly whereby to release the winder ratchet mechanism and simultaneously pull upwardly on the ratchet assembly, causing the winder drum to freely pay out the strap  18 , thereby loosening the tension on the securement strap and main body. The main body member may be slid off of the lift handles L′, L″ without need of disconnecting the securement strap end fittings  20  from their mount. This release operation thus entails only a few seconds from a fully secured tie-down condition to a fully released condition completely separated from the litter structure. Accordingly, both ends of the litter may be released and the litter freed for removal in an exceedingly quick period of time in such an emergency. 
   From the foregoing it will be apparent to those skilled in the art that many changes other than those already described may be made in the size, shape, type, number and arrangement of parts described hereinbefore without departing from the spirit of this invention and the scope of the appended claims.