US 2620493 A
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1952 H. w. BRELSFORD 2,620,493
INSULATED AIR MATTRESS Filed Oct. 9, 1948 1N VEN TOR.
Wa /4W Patented Dec. 9, 1952 Claims.
My invention relates to sleeping equipment and has particular reference to an insulated air mattress.
Inflatable mattresses are generally employed for sleeping and resting purposes whenever weight or bulk become factors to consider. Thus, on camping trips they are commonly employed not only because of their light weight, but because of their small volume compared to conventional mattresses. Also for lawn or beach use, they are convenient to carry, either inflated or deflated, because of their light weight.
Conventional air mattresses, however, have a serious drawback compared to regular mattresses in that they lack comparable insulating values. A regular stuffed mattress may have an effective thickness of from two to six inches of cotton, wool or similarstufling, whereas an air mattress has only the modest insulating effect of anenclosed volume of air an inch or more in thickness.
Nor can this .poor insulating effect be easily overcome by the use of conventional sleeping robes. If a down sleeping bag is used on top of the air mattress, .the weight of the sleeper compresses the down to such a small thickness that the major portion of the insulation of the down is lost. The same effect occurs with other compressible substances such as kapok and to a much lesser extent with blankets such as wool blankets. The poor insulating characteristic of .airmattresses, which is especially noticeable under outdoor winter conditions, may be overcome onlyv by supplying bulk in the form of blankets, mattresses, etc., thus effectively defeating the salient advantages of air mattresses, namely, lightness and compactness.
I have devised an air mattress. that has insulating values equal orsuperior to a like thickness of stuffed mattress. I achieve this result without sacrificing the light weight or small volume of air mattresses. Thus, air mattresses constructed in accordance with my invention will have adequate insulating characteristics even under severe winter outdoor conditions. Further, the light weight and high insulating characteristics of my mattress make it feasible to employ the air mattress as the bottom portion of a sleeping bag, providing a soft support, as well as great warmth.
My invention includes the placing of a light weight compressible, insulating material in the interior of an air mattress. When the air mattress is inflated, the compressible insulation such as down,'down and feathers mixture, kapok, milkweed down, etc., expands to completely fill the interior of the air mattress, thus achieving maxi- UNITED STATES PATENT OFFICE INSULATED AIR MATTRESS Harry W. Brelsford, Santa Barbara, Calif. Application October 9, 1948, Serial No. 53,669
'fiated asillustrated in Fig. 1, the lengthwise tubes l5.
mum insulating values. The weight of the sleeper will not compress the insulation because of the support of the air mattress. When the mattress is deflated the insulation may compress to a very minute thickness, thus adding little to the bulk of the rolled or folded air mattress. By employing light weight (but highly efficient) insulation, the weight increase is negligible.
It is, therefore, a principal object of my invention to provide a lightweight air mattress with good insulating characteristics.
Another object is to provide an air mattress having compressible and expansible insulation disposed in the inflatable chambers thereof.
. Still another object is to provide a sleeping bag having the ground engaging portion thereof formed of an air mattress with insulation disposed within the inflatable chambers of the air mattress.
Other objects and advantages of my invention will be apparent in the following description and claims considered together with the accompanying drawings forming an integral part of this specification, and in which:
Fig. 1 is a perspective view of an air mattress embodying my invention;
Fig. 1A is a perspective view of the air mattress of Fig. 1 as rolled up in a deflated condition;
, Fig. 2 is a section view along the line IIII of Fig. 1;
Fig. 3 is a sectional view through a tubular type of air mattress embodying my invention;
Fig. 4 is a longitudinal sectional view through the tubular air mattress of Fig. 3;
Fig. 5 is a fragmentary perspective of a tuft type of air mattress embodying the invention;
Fig. 6 is a perspective view of a sleeping bag wherein the ground engaging the portion thereof is comprised of an air mattress embodying-the invention; and
Fig. '7 is a sectional view of the air mattress of Fig. 6, but showing the upper portion spaced from the air mattress thereof as in actual use.
Referring 0t Figs. 1, 1A and 2, an air mattress Ill 'may include upper and lower envelope portions H and I2 tied together at intervals along lines by threads l3, which act as connectors for the two portions. The envelope portions II and 'l 2 may be formed of any type of airtight material and the threads I3 may be fused or welded to the upper portions in an air-tight manner. An inflating tube l4 may be provided atone corner of the air mattress and when the mattress'is inthreads define The air mattress construction, as just described, is generally conventional in construction. However, in providing an air mattress in accordance with my invention, the tubular segments (5 may be filled with a light weight compressible insulation I6 such as duck or goose down, down and feathers mixture, kapok, milkweed down, etc. As the air mattress is inflated, the insulation will expand to fill the volume of the tubes I5 and, accordingly, a very efficient insulation will be provided. The insulation will be'engaged by the threads l3 and prevented from shifting due to rough handling while inflated or due to extremel rapid inflation or deflation.
Illustrated in Figs. 3 and 4 is a modifiedform of my invention as applied to a tubular type of air mattress. This type of construction is commonly employed when the air mattress is con structed of thermo plastic, organic plastic materials of which the vinyl compoundsare examples. Accordingly, the air mattress may include-upper and lower envelope. portions. I! and I8 that aresealed together at their edges H3 and along intermediate strips 2| to define distinct tubes 22. This joining is accomplished by a simple application of heat to the thermal plastic material-and at the same time applying. a slight pressure. An air nipple may-beprovi'ded and a manifold may deliverain to all tubes- The tubes may be filled with compressible insulation 23-to providean-Iinsulated air mattress. The insulation may be prevented from shifting 'by theprovision of positioners which may be lengthwise threads-2 4 in the center of each tube which threads may have regular tufts formed thereon as at 25 bytying thereto a small quantity of material such as feather, down, fabrics, etc. Thus, the insulation'wi-ll-engage these tufts 25 and can be prevented from moving in the tubes because of this engagement. The ends of'the threads 24 may be heat welded into the outer joining seam I9: of the mattress.
Illustrated in Fig. 5 is an application of my invention to the tuft type of air mattress generally designated by the letter 2-6 and employing upper and lower envelope portions 21=and 28 tufted at intervals by oppositely disposed pairs of buttonszs. Thebu'ttons may engage each other or may be tied together as by threads 3| and the juncture of the envelope portions with the buttons may be rendered airtight by them;- plicationof a suitable'coating such as liquid rubber;
Referring to Figures 6 and '7, my invention may be applied to a sleeping bag 32 which may include an air mattress 3-3 constructed in accordance'with my invention, as the ground engaging portion, and may include an upper robe or cover 34 secured to the mattress 33. The air; mattress 33 may include upper and lower envelope portions 35 and 36 connected together by'strips of material 31 that are preferably perforated to allow the free passage of air. The tubular sections defined by the strips '31 may be filled with ditional' bottom member is required for the sleepingbag 32 inasmuch as the mattress 33 supplies both comfort in sleeping. and adequate insulation.
The upper robe 34 may be of the usual sleeping bag construction employing overlapping tubes 39 1y necessary. The upper robe 3t-may be securely fastened to the air mattress 33 at one edge as at 4| and may be secured by means of a slide fastener 42 along one edge and the bottom.
It is a feature of my sleeping bag construction that the outermost tubes of the air mattress 33 may be slightly larger than the remaining of the tubes, thus resisting any tendency of the sleeper to roll off of the air mattress, and in effect centering his body automatically. An inflating nozzle 42 may be provided which may include the usual cap or valve to retain the air within the mattress.
The manufacture of the various air mattresses may be in accordance with the present practices except for the modification of inserting the insulation prior to sealing the ends of the air mattress. Thus, any conventional material may be employed such as sheet rubber, rubberized fabric,.
various of the elastic plastics such as vinyl chloride, vinyl chloride-acetate, and poly-vinyl butyral. Also, various of the synthetic rubbers or other elastic materials could be used. The air mattress envelope may be completely formed except that one end may be left open. The insulating material may then be inserted through this open end and when this has been completed the air mattress. may be sealed. In the event of the insertion of the thread 24- of Fig. 4, special care must be taken so that both ends of the thread are sealed into the joint. v
.In operation, my air mattress may be used as any ordinary air mattress and air may be supplied by mouth or by pump, although this latter instrumentality is desired to avoid the collection of moisture withinthe air mattress. The inflation of-the mattress permits the insulation to expand, thereby achieving its maximum insulating values. The inflation of the air mattress likewise. provides a comfortable resting mattress in that the user thereof is spaced from the ground. When the user is finished with the mattress, the cap on the inflating nozzle may be removed and the mattress deflated. It will then roll into a small compact bundle as illustrated in Fig. 1A,'with very little increase in either bulk or weight due to the presence of the insulation.
I have found, for example, that 1 /2 pounds of down will adequately insulate a fulllength air mattress and thus will add but little weight to the mattress.
'The net result of my invention, therefore, is thetprovision of an air mattress that has all of the insulating value of a conventional air mattress of the same or greater'thickness without sacrificing either-the Weight or bulk of an equivalent size plain air mattress. Furthermore,.the airtight construction of the mattress makes the mattress ideally'suited-for wet conditions inasmuch as it is also waterproof. These advantages achieve-their greatest usefulness when the air mattress *is employed as the ground portion of the sleeping bag so that the waterproof, insulating, and soft, supporting characteristics of my air-mattressv may be-em-ployed. I r a I am familiar with the fact that ordinary cushions provided with air vents have also been provided with airyalves so as to give a pneumatic type of cushion rest. However, in all such devices the stufling of the cushion. is such that it causes the 'air to enter the cushion and co'nsequentl'y a very heavy'construction results. My air mattress, by comparison, is extremely light in weight as well as being deflatable to assume a very small'bulk.
While I have described presently preferred. em-
bodiments of my invention, it will be obvious to those skilled in the art that various modifications could be made without departing from the true spirit and scope of my invention. Accordingly, the disclosure of this application is merely illustrative and is not limiting or definitive.
1. An air mattress comprising an airtight envelope, means for admitting and releasing air to and from the envelope, and a downy insulation disposed within the envelope and which is expansible to flll the envelope when inflated and which insulation compresses to a minute volume when subject to compressive forces, said insulation offering no support to the envelope when inflated and permitting compact rolling or folding of the envelope when deflated.
2. An air mattress comprising an airtight envelope, connectors securing opposite walls of the envelope, means for admitting and releasing air to and from the envelope, and a downy insulation disposed within the envelope and engaging the connectors to thereby become postioned within the envelope, said insulation being expansible to fill the envelope when inflated and said insulation being compressible to a minute volume when subject to compressive forces, and offering no support to the envelope when inflated and permitting compact rolling or folding of the envelope when deflated.
3. An air mattress comp-rising an airtight envelope divided into a plurality of tubular sections, a pcsitioner disposed lengthwise in each section and secured to the envelope, means for admitting air to and releasing air from the envelope, and a downy insulation disposed within each section and engaging the positioner, said insulation being expansible to fill each tubular section of the envelope when the section is inflated and being compressible to a minute volume when subjected 4 to compressive forces, and offering no support to the envelope when inflated and permitting com- 6 pact rolling or folding of the envelope when deflated.
4. A sleeping bag comprising a ground engaging portion and an upper robe, said ground engaging portion comprising an airtight and waterproof envelope, means for inserting air into and releasing air from the envelope, and a downy insulation disposed Within the envelope and which is expansible to flll the envelope when inflated and which insulation compresses to a minute volume when subjected to compressive forces, said insulation offering no support to the envelope when inflated and permitting compact rolling or folding of the envelope when deflated.
5. In a sleeping bag, a ground engaging section comprising an elongated airtight envelope, having opposite Walls, connectors disposed between the walls, and forming a plurality of lengthwise tubular sections, and air inlet connected to the envelope, and a downy insulation disposed within the tubular sections, characterized by the outermost tubular sections being larger than the others, said insulation being expansible to flll each tubular section when the envelope is inflated and being compressible to a minute volume when subjected to compressive forces, said insulation offering no support to the envelope when the envelope is inflated and permitting rolling or folding of the envelope when the envelope is deflated.
HARRY W. BRELS-F'ORD.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,332,983 Sylvester Mar. 7, 1920 1,352,231 Wehrenberg Sept. 7, 1920 1,648,373 Vilas Nov. 8, 1927 2,253,801 Neal Aug. 26, 1941