US 2360371 A
Description (OCR text may contain errors)
Oct. 17, 1944.
A. H. SCHWICHTENBERG 2,360,371
FOLDING LITTER Filed July 1, 1941 2 Sheets-Sheet l 44 55/? 7- /7. 60/7 1400 TEA/554 6 raw/v.5):
1944- A. H. SCHWICHTENBERG 2,360,371
FOLDING LITTER Filed July 1, 1941 2 Sheets-SheetZ a imF/VE/S Patented Oct. 17, 1944 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.
The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.
Thi invention relates to litters and more particularly to litters of the folding type wherein the side rails are hinged so that the entire structure may be reduced to a relatively short and compact bundle.
One of the objects of this invention is to provide a litter which is suitable for airplane and field use. This, of course, necessitates a litter which is light in weight but yet strong and rugged in construction. To meet these requirements, the side rails are made of tubular steel and are provided with a hinge having great lateral rigidity.
Another object is to provide a litter in which the canvas cover can be easily removed and a new one substituted with the minimum of time and effort. To accomplish this change, it is only necesary to remove four nuts and the supportings legs whereupon the damaged cover may be slipped off of the side rails and a new one slipped on.
Another object is to provide a litter of simple construction which is cheap and economical to manufacture.
With these and other objects in view, the in-' vention consists of certain novel features of construction as will be more fully described and pointed out in the appended claims.
In the drawings:
Figure 1 is a bottom View of the assembled litter showing the general arrangement thereof:
Figure 2 is a side elevation of the same;
Figure 3 is an end view of my litter;
Figure 4 i a fragmentary view showing the details of my novel hinge construction;
Figure 5 is a fragmentary view showing the details of the supporting legs and the method of attaching the same to the side rails of the litter;
Figure 6 is a cross sectional elevation taken on the line VIVI of Figure 4. and
Figure 7 is a cros section of the side rail taken on the line VII-VII of Figure 5.
The general arrangement and construction of my improved form of litter is shown in Figure l, where 1 indicates generally the tubular steel side rails of the litter, 2 represents the fabric cover extending between the side rails, 3 indicates generally the spreader bars for maintaining the.
spacing between the side rails and 4 indicates generally the folding hinges located in the middle of each of the side rails l. The side rails l are constructed of thin-walled steel tubing, thereby affording a rail of great stiffness and strength which, at the same time, is very light in weight. These rails are hinged in the middle as at 4 in order that the litter may be folded into a short bundle for carrying. Canvas handgrips 5 are cemented to the ends of the side rails so as to provide a better gripping surface for the hands of the bearers than that afforded by the naked steel tubing. Canvas is used in place of rubber for the reason that it does not deteriorate as rapidly and is generally more suitable for this purpose than rubber. The fabric cover 2 is preferably made of a good grade of canvas duck and is hemmed lengthwise as at 6 to form longitudinal pockets or hems l for receiving the side rails I. Cut-outs 8 are provided in the vicinity of the hinge l in order to permit folding at this point without any interference from the cover. Reinforcing strips of webbing 9 are sewn to the cover 2 as shown in Figure 1, these strips extending diagonally across the litter from the end of one spreader bar to the end of the other. Grommets I0 and l I are fitted into apertures provided in the cover 2 to allow for the passage of the bolt and bracket holding each of the supporting leg l2 to the side rails. These grommets may be more clearly seen in Figure 5 where the details of the leg construction are shown. As will be observed from Fig. 1, the supporting legs I2 for the litter are so located along the side rails that they will nest together when the litter is folded. That is, the right hand legs (Fig. 1) will not strike against the left hand legs when the side rails are folded, but will fall to the right thereof so as not to interfere with the compact folding of the litter. This is due to the fact that the legs on the right hand section of the stretcher are placed closer to the pivotal hinges 4 than are the legs on the left-hand section of the stretcher.
The spreader bars 3 are-formed of two bars l3 and I4 Of approximately equal length, which are pivotally fastened to the side rails of the bolts l5 and which are pivotally connected to each other in the center by the bolts Hi. The shape of these spreader bars may be more readily seen in Figure 3, where it will be observed that strengthening ribs l1 and I8 are formed on the bar I3 and I4 respectively, to stiffen the latter and to prevent them from buckling when placed under a compression load. It will also be observed from this figure, that the rib I'l isplaced on the upper side of bar l3, while the rib I8 is placed on the lower side of bar [4. This is necessary in order that the bars may nest together when folded without any interference from the ribs. An abutment I9 is formed on each of the bars I3 to prevent the bars going beyond the position shown in Figure 1. When in their open position (Fig. 1), the bars lie slightly beyond the dead center position so as to prevent their folding up inadvertently. When the bars are in this open position the abutments I9 on bars I3 strike against flat surfaces on bars I4 and so prevent any further movement of the bars to the left in Figure 1. The spreader bars may be readily folded by placing the litter in a vertical position with the right-hand ends of the side rails (Figure 1) on the ground and pulling down on the upper spreader with the hands while pushing down on the lower spreader with one of the feet.
In order that there shall be no tendency of the side rails to bend inwardly at the hinges 4 when the patient is placed on the litter, I have em-.
ployed a novel form of hinge having great strength against horizontal bending loads as well as against vertical bending loads. The details of this hinge may best be seen in Figure 4 of the drawings. As there shown, a bifurcated hinge member 20 is welded to the under side of the left hand half 2I of the side rail I. A mating hinge member 22 is welded to the under side of the right hand half 23 of the side rail, this member being of such thickness as to flt snugly within the bifurcation of member 20. A hinge bolt 24 joins the hinge members near the bottom thereof as shown. The member 22 is rounded to a radius 25 in order that it may clear the under side of the left hand portion of the side rail I when the rail is folded up. A short piece of steel tubing 26 having an inside diameter equal to the outside diameter of rail I is slipped over the end of the left hand half 2i of the rail and is welded thereto as shown. Th right hand end of piece 26 surrounds the end of the right hand half 23 of the rail, the piece 26 being split along the bottom and having the sides straightened out as at 21. The details of this construction may be more readily seen by referring to Figure 6. It will be noticed that the sides 21 are left to toe in slightly at the bottom, as shown in Fig. 6, in order that the right hand rail may snap into the piece 26 when the rails are opened up. A short piece of tubing 28 having an outside diameter equal to the inside diameter of the side rail I is inserted in the end of the right-hand half 23 of the rail (Figure 4) with a portion of this tubing extending within the interior of the left-hand portion 2I of the side rail I. This latter portion of the tubing 28 is rounded off at 29 to permit the lefthand portion of tubing 28 to clear the inside wall of the side rail when the rails are folded up.
From the above description it will be evident that three features of the hinge construction safeguard against bending in a horizontal direction, viz., the meshing of the flanges 20 and 22, the piece 26 which surrounds the sides of the right hand section 23 and the short tube 28 which bears against the sides of the interior wall of the left hand section 2!. Downward bending at the joint is likewise prevented by three features of construction, viz., th location of the hinge pin 24 below the side rail, the piece 26 which lies over the top of the right hand section 23 and the short tube 28 which bears against the bottom of the interior wall of the left hand section 2 I.
It is also to be noticed, that the piece 23 tends to shield the hinge and so prevent injury to the patient from pinching parts of his body therein.
Provision has been made for facilitating the quick removal of the fabric cover 2 from the side rails whenever the cover has been damaged and a new one needed. Its ready removal is made possible by the novel arrangement for attaching legs I2 to the side rails, the details of which are best shown in Figure 5. As there shown, a bolt I 5 extends through the side rail from top to bottom, holes being drilled in the side rail for this purpose. to the top of the rail to hold the bolt fast therein. The grommet II) of the cover slips over the lower end of the bolt I5 as shown. The leg I2 is made in the shape of a U with the upper ends of the U bent over to form flanges 3| and 32. The flange 3I is provided with a hole for accommodating the bolt I5. The flange 32 is received in a bracket 33 which is welded to the under side of the rail I as shown in Figure 7. The elongated grommet II is located in the canvas cover 2 in a position to slide over the bracket 33. It will now be apparent that in order to loosen the cover from the side rails, it is only necessary to remove the legs I2 from the bracket 33 and the bolt I5. This may be done by unscrewing the nut 34 for each leg and removing the washer 35 and the spreader bar whereupon the leg may be slipped off the bolt I5. The flanged end 32 of the leg may then be slid out of the bracket 33 and the leg removed. The grommets of the cover 2 may then be pulled off of the brackets 33 and the bolts I5 and the cover slid off the side rails I. The grommets Ill and [I may be easily removed from the bolt and bracket due to the ample width of the pocket or hem 1 formed in the cover. Thus, the cover, while securely fastened to the side rails when the litter is in use, may be easily and quickly removed therefrom when a new cover is found necessary.
From the foregoing, it will be seen that I have constructed a litter which is light in weight and, at the same time, extremely strong and rugged in character. The litter may be folded into a compact bundle for convenience in carrying from place to place and also for economy of space when packed in an airplane or truck. The simple design of my litter also makes for rapid and inexpensive construction thereof.
Having thus described my invention, what I claim as new and what I desire to secure by Letters Patent is:
1. A folding litter comprising a pair of side rails, a fabric cover having a pair of wide, longitudinally extending hems for receiving said rails, each of said hems being provided with a plurality of apertures therein, a plurality of supporting legs each having a pair of horizontally extending flanges on'the upper end thereof, one flange of each of said pairs having a hole therein, and means for removably fastening each of said legs to the underside of said rails, said means including in each case a first element permanently secured to the underside of one of said rails and projecting through one of the apertures provided in one of said hems where said element is provided with an aperture for receiving one of said flanges, a second element permanently secured to said rail in spaced relationship with respect to said first element, said second element being adapted to extend below said rail where it projects through another of the apertures provided in said one hem and through the hole formed in the other of said flanges, and removable retaining means for holding said leg and said cover in place on said second element.
2. A folding litter comprising a pair of side The head of the bolt 30 is tack-welded' rails, a fabric cover having a pair of wide, 10ngitudinally extending hems for receiving said rails, each of said hems being provided with a plurality of apertures therein, a plurality of transverse spreader bars extending between said rails, a plurality of supporting legs, each having a pair of horizontally extending flanges on the upper end thereof, one flange of each of said pairs having a hole therein, and means for removably fastening each of said legs and said spreader bars to the underside of said rails, said means including in each case a first element permanently secured to the underside of one of said rails and projecting through one of the apertures provided in one of said hems where said element is provided with an aperture for receiving one of said flanges, a second element permanently secured to said rail in spaced relationship in respect to said first element, said second element being adapted to extend below said rail where it projects through another of the apertures provided in said one hem and through the hole formed in the other of said flanges and in the end of one of said spreader bars, and removable retaining means for holding said spreader bar, said leg, and said cover in place on said second element.
ALBERT H. SCHWICHTENBERG.