BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a vehicle-mountable patient support system (PSS) for supporting and manipulating the position of a litter within a vehicle in accordance with a preferred embodiment of the present invention. The PSS is illustrated in an contracted lateral position.
FIG. 2 is a rear end view of the vehicle-mountable patient support system of FIG. 1. The PSS is shown in an extended medial position used to load the litter onto the PSS.
FIG. 3 is a rear end view of the vehicle-mountable patient support system of FIGS. 1 and 2. The PSS is shown in a contracted lateral position used to transport the patient after the litter has been loaded onto the PSS.
FIG. 4 is a rear end view of the vehicle-mountable patient support system of FIGS. 1-3 wherein the portion of the PSS that supports the litter is folded upward when not in use.
FIG. 5 is a top view of the PSS of FIGS. 1-4 illustrating the litter lock mechanism disposed on the litter support rails.
FIG. 6 is a top detail view of one of the two bidirectional litter locking mechanism of the PSS illustrating the action of litter locking mechanism disposed on the litter support rails when a litter is placed on the rails and advanced to a forwardmost position.
FIG. 7 is a top detail view of one of the two unidirectional litter locking mechanism of the PSS illustrating the action of litter locking mechanism disposed on the litter support rails when a litter is placed on the rails and advanced to a forwardmost position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a preferred embodiment of the patient support system of the present invention, a pair of litter support assemblies are attached to the opposing side walls in the cargo bed of a vehicle. For simplicity, only a single support assembly will be described. It will be clear to the artisan that a second assembly, adapted for attachment to an opposing side wall in the cargo bed, is a mirror image of the first assembly described below.
With reference to FIGS. 1 and 2, a litter support system 10 in accordance with the present invention comprises front 101 and rear 106 chassis mounting portions adapted to be attached to a side wall 206 (FIG. 2) in the bed of a vehicle (not shown), front and rear lateral adjustment portions 100 attached to the respective front and rear chassis mounting portions 101 and 106 and a rectangular litter supporting portion comprising “C-channel” rails 111 and 112 attached to, and, in turn, supported by, members 104 and 109 of the lateral adjustment portion 100.
The front and rear lateral adjustment portions 100 are identical and are sometimes referred to in the art as “straight-line” mechanisms. Since the front and rear lateral adjustment portions 100 are identical, only one needs description. The rear straight-line mechanism 100 includes members 106, 107, 108, 109, and 110, shown in a collapsed or laterally contracted configuration in FIG. 1, and a fully extended configuration in FIG. 2. FIG. 2 also shows a simplified vehicle interior wall layout 206 and vehicle centerline 207 indicated by dashed lines. The patient 113 and litter 114, shown in phantom in FIG. 2, are positioned at the approximate position of maximum extension of the lateral adjustment portions 100. The wall mounts 101 and 106 are attached to the wall 206 or other support structure and are provided with pivotal attachment means 202, 204 (FIG. 2) for pivotally attaching member 110 of the lateral adjustment portion 100 to the rear chassis attachment portion 106. The individual members 107, 110, 108, and 109 comprising the rear lateral adjustment portion 100 incorporate pivots at points 201, 202, 203, 204, and 205. The patient 113, supported by a litter can be loaded onto the litter support system 10 with the rails 111 and 112 of litter support portion of the assembly 10 positioned in a medial, litter-loading position shown in FIG. 2 for optimum access and clearance with the vehicle's (ambulance's) rear doorway.
When a laterally-directed horizontal force is applied to the left C-Channel rail 112, the litter support portion (comprising support member 109 and rails 111 and 112) moves laterally (i.e., toward the right) until a stop is reached. The stop can be incorporated into the mechanism 100 or be a part of the non-movable structure. The assembly 10 is then in the transport position as shown in FIG. 3. Stops are provided in the mechanism so that it can be locked and held firmly in any number of positions desired between the loading position shown in FIG. 2 to the transport position shown in FIG. 3. By attaching the assembly 10 to the wall 206 of the vehicle bed, floor space is freed up for storage of medical equipment or supplies and an attendant.
Two identical mechanisms 100, one front and one rear as described above, are required in order to provide a stable litter support system 10 as shown in FIG. 1. The distance between the two support mechanisms would normally be approximately the same as the distance between the stirrups on a NATO-style litter but can be positioned as driven by other requirements. Stability of the two mechanisms in a direction parallel to the wall that the two litter support systems are mounted on can be accomplished by several means. For example, a structural member such as a torque tube 114 (FIG. 1) can be interposed to connect a common point on members 104 and 109 of each mechanism 100 to provide the desired lateral stability.
The two C-channel members identified in FIG. 1 as members 111 and 112 are attached to members 104 and 109. These two members 104, 109 support rails 111 and 112 which facilitate loading the patient into the litter support system 10 as well as restraining the litter during transport. When loading a litter, the stirrups on the forward end of the litter are inserted into and supported by the rearward end of the two C-channels 111, 112. The litter is then slid forward within the C-channels until the second rear litter stirrups are slid onto and supported by the C-channels (i.e., rails) 111, 112. The litter is then further advanced along the rails until it is prevented from moving further by stops 501 disposed within the C-channel of the rails 111 and 112 at the forward end thereof as shown in FIG. 5. The stirrups on the litter are then automatically locked into place preventing motion of the litter relative to the litter support portion in any direction. When unloading the litter, the stirrup locks are released and the procedure is reversed. The rearward ends of the supporting C-channels in rails 111 and 112 are preferably widened 504 at the rearward ends thereof where the litter stirrups are first inserted to facilitate ease of insertion. The release control for the locks for the litter support stirrups as well as the inboard outboard translation position are placed in a convenient location for the operator. The two C-channel rails 111 and 112 can be attached to support members 104 and 109 by a quick disconnect device that requires no tools to connect or disconnect.
Referring now to FIG. 4, when the litter support assembly 10 is not being used, both C-channels 111 and 112 can be removed from the support members 104 and 109. More preferably, support members 104 and 109 (only litter support member 109 is shown in FIG. 4) are pivoted upward about point 205 for storage. After the assembly is folded into a stowed position as shown in FIG. 4, member 109 can be restrained from unwanted rotation with respect to member 108 by a detent assembly disposed on member 109 and 108, the detent assembly being operable for the releasable engagement of respective members and restraint of rotation of member 109 with respect to member 108.
FIG. 5 is a top view of the patient support system 10 generally illustrating the automatic locking system used to secure a litter to the assembly 10. The litter locking system consists of four spring loaded lock mechanisms 11, 12, 13, 14 and two permanent stops 501. NATO-style litters generally have four supporting feet or stirrups disposed on, and projecting downwardly from, the lower surface thereof. Each of the four locks is positioned to engage one of the four stirrups on the underside of the litter. More specifically, each of the C-channels 111 and 112 is fitted with one unidirectional lock 11, 12 at the forward end thereof, and one bidirectional lock 13, 14 at the rear end thereof in order to engage and restrain the forward and rearward stirrups respectively. The spacing between the locks 12 and 13 and between locks 11 and 14 is approximately equal to the longitudinal spacing between the stirrups of a NATO-style litter. Once engaged, the locks 11, 12, 13, 14 prevent the litter from moving upward or rearward with respect to the cargo bed. Forward motion is prevented by the permanent stops 501 disposed at the forward end of the C-channels. In order to remove a litter from the support system 10, the bidirectional locks 13, 14 must be manually disengaged.
The locking system incorporates two types of lock mechanisms. The bidirectional locks 13 and 14 restrain motion of a litter stirrup in both the upward and rearward directions, while the unidirectional locks 11 and 12 prevent upward motion only. FIG. 5 depicts the bidirectional locks 13 and 14 disposed at the rearward end of the C-channels 111 and 112, and the unidirectional locks 11 and 12 disposed at the forward end of the C-Channels 111 and 112. The system is designed to be operated from the rearward end of the support system 10 where the bidirectional locks 13 and 14 are attached. If it is necessary to operate the locks 13 and 14 from the front end of the support system 10, this configuration can be reversed. Once the stirrups are fully engaged by the respective locks, the locks 11, 12, 13, 14, together with the permanent stops 501, prevent any motion of the litter with respect to the support system 10.
A top view of the right, rear bidirectional lock 14 is shown in FIG. 6. It is clear to the artisan that the left rear bidirectional lock 13 is a mirror image of the lock 14. From its default position (shown in solid lines), the lever 601 is limited to rotation in the counterclockwise direction as indicated by the dashed arc. The lever 601 is shaped in such a way as to both maximize the surface area that contacts the vertical face of the litter stirrup, and minimize the size of the required cutout in the side of the C-channel 111 through which cutout the lever 601 extends into the C-channel. As a litter stirrup (not shown) approaches the lever 601 from the right, it first contacts the angled face 604, and rotates the (spring-loaded) lever 601 in a counterclockwise direction completely out of the path of the stirrup. Once the leading edge of the stirrup has passed the tip of the lever, a spring mechanism 602 returns the lever, to its locked position. When the lever returns to occupy a cutout in the stirrup, the stirrup is prevented from moving either upward or rearward. When the litter is to be removed from the litter support assembly 10, bidirectional locks 13 and 14 are disengaged from the stirrup by pulling (or pushing) on the release cord hand grip 502, shown in FIG. 5 which applies tension to the release cord or cable 503 around the pivot wheel or pulley 603 causing a counterclockwise rotation of the lever 601. The lever disengages the litter stirrup as it is withdrawn from the center of the C-channel 111. Because the release cable 503 is also connected to the bidirectional lock 13 on the adjacent C-Channel 112, the locks 13 and 14 will simultaneously disengage and release their respective litter stirrups. The lever drawn in phantom lines represents this fully open (disengaged) position of lever 601 when tension is applied to the cable 503. Once the litter has been removed, the release cord hand grip 502 is released, and the spring mechanism 602, returns the lever to its default position.
A top view of a forwardly disposed unidirectional lock 11 is shown in FIG. 7. Unidirectional locks 11 and 12 are affixed to the outer wall of the forward ends of the C-channels 111 and 112 and are identical. The lock 11 comprises a spring-loaded lever 701 that projects into the C-channel in rail 111 through a cutout as shown. From the default position (shown in solid lines), the lever 701, is free to rotate in both clockwise and counterclockwise directions when urged to do so by an applied force. As a litter stirrup approaches the lever 701, it applies a force that urges the lever to rotate in a counterclockwise direction. Once the leading edge of the stirrup has passed the tip of the lever 701, a spring mechanism 702 returns the lever 701 to its default position. With the lever positioned within a slot in the stirrup, the stirrup will be prevented from moving upward. The lock is disengaged by pulling the litter rearward until the stirrup has rotated the lever 701 completely out of the C-channel in the clockwise direction.
Although a straight-line mechanism is described herein as comprising the lateral adjustment portion 100, the present disclosure contemplates the use of similar mechanisms for the lateral adjustment portion 100 that perform the same function. One example is an arrangement of telescoping square tubes. While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
Patent Application
20080023976
