US 3797051 A
A foldable stretcher includes a pair of U-shaped frame members hingedly connected together to permit folding of the stretcher between a normal extended position and a folded position. A flexible support panel is secured to the U-shaped frame sections and is provided with recesses or cutouts adjacent the corners and hinge connections of the stretcher to facilitate carrying thereof. A pair of lock bolts are provided, each being positioned within the leg of one U-shaped frame section and being urged by a coil spring into the leg of the other U-shaped frame section when the stretcher is in the extended position. A pair of retaining cam elements are provided for retaining the lock bolts in a retracted position when the stretcher is in the folded position.
Description (OCR text may contain errors)
United States Patent [191 Evans [4 1 Mar. 19, 1974 FOLDABLE COT Primary Examiner-Casmir A. Nunberg Attorney. Agent, or FirmWilliamson. Bains & Moore 5 7 ABSTRACT A foldable stretcher includes a pair of U-shaped frame members hingedly connected together to permit folding of the stretcher between a normal extended position and a folded position A flexible support panel is secured to the U-shaped frame sections and is provided with recesses or cutouts adjacent the corners and hinge connections of the stretcher to facilitate carrying thereof. A pair of lock bolts are provided, each being positioned within the leg of one U-shaped frame section and being urged by a coil spring into the leg of the other 'U-shaped frame section when the stretcher is in the extended position. A pair of retaining cam elements are provided for retaining the lock bolts in a retracted position when the stretcher is in the folded position.
5 Claims, 5 Drawing Figures PATENTEB AR 1 9 B974 l ff .Z
IL/ I FOLDABLE COT BRIEF SUMMARY OF THE INVENTION Many hospitals and other institutions retain a supply of stretchers, and the length dimension of these stretchers presents a space or storage problem when the stretchers are not being used. Although there are some foldable type stretchers now available, many of these foldable types are laterally foldable and the length dimension is therefore not reduced when these stretchers are in the folded condition.
It is therefore an object of this invention to provide a novel foldable stretcher which is foldable along its transverse center line between a folded position and an extended position.
The foldable stretcher is provided with unique lock bolts which are normally urged into a locking condition when the stretcher is in the extended position whereby the stretcher is automatically locked when unfolded into the extended position. The lock means comprise spring urged lock bolts which are retained by cam elements in a retracted release position within the respective legs of the U-shaped sections when the stretcher is folded. With this arrangement, the stretcher may be readily folded into a relatively compact condition but is automatically locked when unfolded into the extended position.
These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the novel stretcher in the extended position;
FIG. 2 is a perspective view of the novel stretcher in the folded condition;
FIG. 3 is a fragmentary elevational view illustrating the interrelationship of the various components of the hinge and locking meanswhen the stretcher is in the extended position;
FIG. 4 is a fragmentary elevational view similar to FIG. 3 illustrating the interrelationship of the various components of the hinge and locking means when the stretcher is in a folded condition; and
FIG. 5 is a cross-sectional view taken approximately along lines 5-5 of FIG. 3 and looking in the direction of the arrows.
DESCRIPTION OF THE INVENTION Referring now to the drawings and more specifically to FIG. 1, it will be seen that one embodiment of the novel foldable stretcher or 10 is there shown. The foldable stretcher 10 includes a foldable frame 11 which is comprised of a pair of similar U-shaped frame sections 12. These frame sections 12 are formed of suitable tubular stock, preferably aluminum, each including a pair of substantially parallel legs 13 which are rigidly interconnected by a transverse portion 14.
These U-shaped frame sections 12 are hingedly connected together by a pair of hinges 15 each including a pair of hinge sleeves 16 which are positioned around and affixed to the free ends of the legs one U-shaped frame section. The hinges 15 also include a pair of hinge sleeves 17 which are positioned around and fixedly connected to the outer or free ends of the legs 13 of the other U-shaped frame section 12. It is pointed out that each hinge sleeve 16 has a substantially flat upper surface 16a while each hinge sleeve 17 has a substantially flat upper surface 17a.
Each hinge sleeve 16 has a pair of elongate substantially straight spaced apart hinge elements 18 fixedly secured to the upper flat surface thereof while each hinge sleeve 17 has a pair of similar elongate substantially straight spaced apart hinge elements 19 affixed to the upper flat surface 17 thereof. Referring again to FIG. 5, it will be seen that the hinge elements 19 are positioned interiorly of the hinge elements 18. It will also be seen that the inner end of the hinge elements 18 and the inner end of the hinge elements 19 are bent to form an arcuate portion or eye as best seen in FIGS. 3 and 5.
The openings defined by the bent ends of the hinge elements are disposed in registering relation with respect to each other, and elongate hinge pin 20 extends therethrough. It is pointed out that the hinge pin 20 of one hinge element is disposed in substantially axial alignment with the other hinge pin 20 so that the U- shaped frame sections are pivotal about transver axis which is located at the transverse centerline of the frame. With this arrangement, the frame 11 is foldable between an extended position, as illustrated in FIG. 1, and a folded position, as illustrated in FIG. 2. It will be noted that when the stretcher is in the extended position, the legs and the hinge sleeves are disposed substantially in abutting relation with respect to each other. However, when the stretcher is in the folded position as shown in FIG. 2, U-shaped frame sections lie upon each other in substantially parallel relation thus reducing the length dimension of the stretcher by onehalf.
Means are also provided for releasably locking the stretcher in the extended position and this means comprises a pair of elongate cylindrical locking bolts 21' which are positioned within the legs of one of the U- shaped frame sections 12. These elongated locking bolts are longitudinally shiftable within their respective leg and each is engaged at its rear endby helical spring 22 which is positioned against a stop pin 23 that extends through the associated leg. Thus each locking bolt is normally urged longitudinally outwardly from a retracted condition within the associated leg.
In this regard, it will be seen that when the stretcher is in the extended condition, each locking bolt 21 will extend outwardly from the retracted position within its associated leg and into the adjacent leg of the other U- shaped frame section. A stop pin 24 extends transversely of the other leg to limit the movement of each stop bolt in a locking or extended direction.
Means are also provided for retracting each locking bolt from its extended locking condition to the retracted condition. Each leg of the U-shaped frame section which accommodates the locking bolt therein is provided with a pair of diametrically opposed elongate slots 27 therein. An actuator collar 25 is positioned around each slotted leg and a pin 26 extends through the locking boltand slots 27 therein and is secured to the actuator collar 25 therein. With this arrangement, each actuating bolt can be retracted against the bias of a helical spring 22 by retracting the associated actuator collar 25.
Means are also provided for retaining and locking bolts 21 in a retracted release condition, and this means includes a pair of retaining cam elements 28, each being secured to one of the hinge sleeves 16. It will be noted that the retaining cam elements 28 are of flat construction each having a curved arucate camming surface 29 whose periphery extends through an are slightly larger than 180. Each cam element 28 has a lower flat surface secured to the associated hinge sleeve 16, as by welding or the like, and projects longitudinally therefrom. Each cam element 28 also projects through a slot 30 in the adjacent leg of the other frame section and through a slot 31 in the sleeve of the last mentioned leg. It will be seen that when the actuator collars 25 are retracted to retract the locking bolts 21 to the retracted release condition, the U-shaped frame sections may then be folded. When this folding occurs, the arcuate camming surface 29 of each cam element immediately engages the arcuate camming surface 21a of the associated locking bolt to continuously engage the locking bolt as the frame sections are shifted to the complete folded condition. Conversely, when the frame sections are unfolded to the extended position, the cam retaining elements 28 will retain the locking bolts in the retracted condition until the sections are fully extended, at which time the locking bolts are urged forwardly into the locked condition by the helical springs 22.
The foldable stretcher also includes a generally rectangular shaped flexible support 32 which may be formed of a suitable strong fabric material. The flexible support panel 32 is provided with peripheral sleeves 33 which are formed by folding the marginal portions of the flexible support over the U-shaped frame sections, the folds being stitched in a well-known manner to form the sleeves 33. lt will be seen that the flexible support panel 32 is recessed at the respective corners 34 and is also recessed, as at 35, adjacent the hinge connect'ions 15. These recesses permit ready and easy gripping of the frame of the foldable stretcher to facilitate carrying the stretcher when supporting a person thereon. I
The stretcher is also provided with suitable elongate retaining straps 36 which are stitched to the support panel 32 and which have opposite ends thereof extending therefrom. The straps 36 are each provided with a self locking buckle 37 at one end thereof to permit the straps to be used to retain the patient in supported relation on the stretcher. Referring now to FIG. 2, it will be seen that one of the-straps may be used to releasably secure the stretcher in a folded condition.
In use, the foldable cot may be stored in a folded condition as shown in FIG. 2'. When in the folded condition, the retaining cam elements 28 very effectively retain the locking bolts in the retracted release condition. When it is desirable to use the stretcher, it is merely necessary to release the retaining strap 36, which is used to retain the stretcher in the folded condition, and thereafter unfold the stretcher to the extended position.
When this occurs, the retaining cam elements retain the locking belts in the retracted condition and are cammed out of obstructing relation with respect to the locking bolts to permit the latter to be urged quickly into the legs of the other U-shaped frame section. This locking action is automatic and highly efiicient. Thus it will be seen that the U-shaped frame sections of the foldable stretcher may be folded through an arc of approximately between extended and folded positions.
This folding and unfolding operation requires a minimum of manipulation since the user is required only to retract the locking bolts by retracting the associated actuator collars 25 at the initial stage of the folding operation. No manipulation is required with respect to the lock mechanism when the device is unfolded to the extended position. It has been found that a single user may effectively and easily fold the stretcher to the folded condntion by standing the stretcher on one end adjacent a wall support or the like and retracting the actuator collars to permit the initial folding of the frame sections. In this regard, the section being folded may be supported by a wall during the initial folding stages, and the user may thereafter complete the folding operation by merely swinging the frame sections together. The unique construction of the hinge and lock means permits this folding and unfolding operation to be accomplished with a minimum of effort by a single user.
The stretcher 10 is of lightweight constraction and may be easily handled when storing and also when the stretcher is being folded or unfolded. It will therefore be seen that I have provided a novel foldable stretcher, which is not only of simple and inexpensive construction, but one which functions in a more efficient manner than any heretofore known comparable device.
What is claimed is:
1. A foldable stretcher comprising,
a pair of U-shaped rigid frame sections each including a pair of elongate substantially parallel hollow legs, and a transverse portion rigidly interconnecting said legs;
a pair of hinges each hingedly connecting the end of a leg of one frame section with the adjacent end of a leg of the other frame section to permit relative pivoting of the frame sections between extended and folded positions about an axis extending substantially through the transverse center line of the stretcher when the latter is in the extended position; 7
each leg of one frame section being disposed in longitudinal alignment with a leg of the other frame section when said sections are in the extended position, said frame sections when in thefolded position being disposed in side by side substantially parallel relation;
a generally rectangular shaped flexible support panel having peripheral portions thereof secured to the legs and transverse portions of each frame section;
a pair of elongate locking bolts each being positioned in a leg of one frame section, andbeing longitudinally shiftable relative thereto between retracted release and extended locking positions, said bolts when in the retracted position, each being disposed in one leg of a frame section, and when in the extended locked position, each bolt projecting beyond the associated one leg to the adjacent leg of the other section to releasably lock the sections in the extended position;
resilient means urging locking bolts to the extended locking position,
and retaining means on the legs of one frame section engaging the locking bolts when the latter are retracted and the frame sections are in the folded position to retain the bolt against extension, and during unfolding of the sections to the extended position, said retaining means being progressively shifted by the legs on said one frame section out of engagement with said locking bolts whereby the locking bolts will be automatically urged to the extended locking position by said resilient means when the frame sections are in the extended position.
2. The foldable stretcher as defined in claim 1 wherein said retaining means comprises a pair of retaining elements each being mounted on the leg of one frame section and each having an arcuate cam surface engagable with the associated locking bolt to urge the same into the leg of the other frame section when said sections are in the folded position.
3. The foldable stretcher as defined in claim 1 wherein each of said hinges comprises a plurality of hinge elements positioned exteriorly of said legs.
4. The foldable stretcher as defined in claim 1 and a pair of actuator elements each being shiftably mounted on a leg of one of said frame sections for longitudinal shifting movement relative thereof, each actuator element being connected with one of said locking bolts whereby upon longitudinal shifting movement of an actuator element in one direction, the associated locking bolt will be shifted in a retracted direction to permit folding of said sections from an extended position.
5. The foldable stretcher as defined in claim 1 and stop means in the legs of the other frame section to limit longitudinal movement of lock bolts in a locking direction.