US2516444A - Treated paper parachute - Google Patents

Description

Patented July 25, 1950 2,516,444 7 TREATED, PAPER PARACHUTE Ralph Anzalone, Baldwin, N. Y., assignor to Leonard P. Frieder, New YorlgN. Y. I

No Drawing. Application November 17,1945,

Serial No. 629,322

My present invention relates to paper parachutes and methods of making same; and more particularly to paper parachutes of the kind which have to be folded or packed in containers of various sorts from which they are ejected or withdrawn when they are put in use for supporting loads, although as will-be apparent later, the invention is not limitedto anyparticular kind of paper parachute.

Asisuch, the present invention: is a continuation-in-part of my prior and co-pending invention, Serial No. 456,037, filed August25, 1942. now abandoned, and having the same title.

Among the objects of the present invention-are to provide a paper parachute whereinthe canopy or sail will not be or become damaged in. folding or packing andwhich will. open quickly and with a highdegree of certainty when freed to retard the-descent of a load.

Another object of the present invention is to provide a method of treating the canopy or sail of a paper parachute, or the paper from which it is madato protect the material from drying out and becoming fragile, particularly along folds in the material.

A further object is to provide. a method of treating. paper parachutecanopies or canopy. material, which. will not only protect them, but which will also serve to preserve the material particularly as against drying out and consequent loss of the desired strength characteristics, thereby insuring quick and certain opening and, incidentally, additionally will protect the material from damage when the canopy unfolds or opens to take on its load.

While the invention is not limited in its application to paper parachutes which are to be packed in containers, .so far as is now known it has its greatest utility in constructing such parachutes for use in supporting pyrotechnic flares, signals, and other similar-things under such conditions that the parachutes. or at least the canopies thereof, are tightly packed in containers, from which they are fired or otherwise ejected, and/or from which they are withdrawn when they are put into use to retard the descent of their loads. In certain respects the invention may be used in whole or in part in connection with parachutes constructed of materials other than paper, but wherein similar troublesome characteristics are met.

The method of practicing the invention varies according to the circumstances of manufacture, including the equipment. available. In its simplest form, where the canopies or sails are rela- 1 Claim. (Cl. 244-145) tively small, and a dipping tank is available, the canopies are dipped into a solution such as is hereinafter described, the excess solution is removed from them by some mechanical means such as mangles, centrifuging, etc., and thereafter they are allowed to dry. In other instances, the solution may be sprinkled or sprayed ontothe canopy. In this respect the sprinkling or spraying is to be considered as the equivalent for the purposes of the present invention, of the dipping step of the process above described. The treatments maybe applied to the canopy as'above set forth after thepieces composing" it have'been assembled and suitably fastened together in cases where the canopy is not composed of a single piece of material.

In larger scale operations, the webof material from which such canopy or pieces thereof are laterto be cut, may be drawn through a tank containing the treating solution or past a suitable installation of devices for spraying or sprinkling the solution onto one or both sides of the web. This web may then be run through suitable rolls or such other mechanical devices as may be de- ,sired for mechanically removing therefrom solution in excess of that amount substantially saturating the web; and thereafter the web may be suitably dried. It may in some instances be advisable to run the treated web through a festoon dryer, particularly if the treated web is to be rolled upand. stored for subsequent or future use.

The solution used for treating the canopies or the material. from which they are to be ,made may vary within certain limits hereinafter more particularly set forth, the essential requirement being that the active ingredient of the solution, which inthis case is glycerine, be introduced into the parachute materialinan amount desired for achieving the optimum results. .In this connection, it is recognized that itis old and well known generally to treatpaper with glycerine. However all such teachings of the treatment of paper with glycerine have failed to recognizecertain essential factors, which-are possibly peculiar to the requirements of the use of paperas a parachute material-or material from which the canopies of such parachutes may be made. It'has been found,"for example, that in order to achieve the best results in accordance with the present invention, a relatively small and substantially predetermined amount of glycerine per unit of area of paper is highly desirable in order to achieve the desired results in accordance with this invention,'-these results being as set forth hereinabove, the preservation of the desired characteristics of the paper against drying out and/or against damage from folding so that the unfolding and suitable opening of the parachute is insured, and the enhancement of the strength factor of the paper considered from the point of view of the strength of the paper when put into use, so that the initial shock, due to the parachute taking up and retarding the descent of its load and particularly the shock upon the initial opening of the parachute will not cause a rupturing of the material of the parachute as will defeat the desired purposes thereof. In this connection it may be pointed out that the certain and sure opening of a parachute, particularly one for use with pyrotechnic devices, is highly important. For example, if the parachute is slow in opening, the velocity of fall of the load prior to the opening may be such that the initial shock upon opening may be sufficient to damage or wholly destroy it and thus permit the too rapid descent of the load. The extreme condition is one in which the parachute wholly fails to open, possibly due to the adhesion of some of the folds to others due to the character of the paper itself or to some treatment thereof, permitting the load to fall rapidly to earth while it is still burning. This may have the effect of an incendiary, due to the character of the loads used in pyrotechnics. It has been found that when the paper of which the parachutes are made is treated in accordance with the present invention, as distinguished from thetreatment heretofore applied to paper in accordance with the prior art, which is either wholly indefinite as to the amount of glycerine to be used, or uses an amount of glycerine greatly in excess of that here found to be proper, that the desired characteristics as above set forth are obtained and retained in the parachutes to a maximum extent. It has further been found that paper treated in accordance with this invention and used as parachute material, is definitely superior both to untreated paper and to paper having substantially larger percentages of glycerine per unit of area.

A highly satisfactory solution for carrying out the present invention is glycerine in a volatile liquid vehicle. This vehicle may comprise one or more volatile, organic solvents which are miscible with glycerine. A preferred material for use as such vehicle is a commercial grade of ethyl alcohol. In preparing the solution, from about 1 to about 4% parts of glycerine are mixed with and dissolved in 100 parts of the volatile solvent as aforesaid.

While the broad limitsas aforesaid for the glycerine in the solution are about 1 to about 4 /2 parts per 100 parts of solvent, it has been found that a preferred composition suitable for treating many ordinary commercially practical types of paper usable in the making of paper parachutes for pyrotechnic use is about 1% parts of glycerine per 100 parts of solvent. In general, the proportion of glycerine should be chosen with regard to the degree of hydration of the paper being used on the principle that higher percentages of glycerine will be employed, within the above limits, for the lower hydrated types of paper.

Experience has hown that average grades of paper such as are usable for the making of canopies or sails of parachuteswill take up about a predetermined amount of the solution, substantially roportional to the weight of the paper- Thus, if the excess solution, or the solution in 4 addition to that amount sufficient to effect substantially complete saturation of the paper, is then mechanically removed in any suitable manner as above generally set forth, there will be substantially a predetermined amount of solution remaining in the paper following these treatment and excess removal steps. Inasmuch as the solution is'made with a volatile solvent which is miscible with glycerine, substantially a predetermined amount of glycerine will be uniformly distributed throughout the parachute material per unit of area upon the evaporation of the volatile solvent. This will and has been proven in practice to effect the desired result of preservation of the paper, so as to facilitate and practically to insure the proper opening of the para chutes without causing the characteristic of stickiness or tackiness, which would result if a larger and undesirable proportion of glycerine were used. It also, through some mechanism or theoretical operation, which theory is not relied upon here and as to which, hence, no explanation will be given, serves actually to increase the effective strength of the paper in use over that of untreated paper when used for this purpose.

Some of the other volatile organic solvents which may be used in conjunction with or in place of the ethyl alcohol in accordance with the present invention, are carbon tetrachloride and ethylene dichloride. Others will occur to those skilled in the art.

The treatment aforesaid may in some instances be augmented ,to provide for surface lubrication by a light dusting of the surface or surfaces of the paper with a non-hygroscopic dry, pulverulent substance, such as powdered talc. It is also contemplated that other dry pulverulent materials, having lubricating characteristics, may be used in place of the talc within the purview of this invention.

While there is described herein but a few of the possible variations fairly coming within the purview of the present invention, it is contemplated that other variants will occur to those skilled in the art from the above teachings. I do not wish to be limited, therefore, except by the scope of the appended claim, which is to be construed validly as broadly as the prior art permits.

What is claimed is:

A paper parachute including a paper canopy, adapted to be tightly packed in afolded condition without damage by such folding and packing and without deterioration instrength at the folds after being kept in said folded condition, and adapted to unfold freely for use, said paper canopy being uniforml impregnated throughout its extent with a substantially predetermined amount of glycerine, the amount of glycerine per unit area of the paper and the uniform distribution of the glycerine throughout the paper being equivalent to the amount and distribution of glycerine which would remain in the paper after first saturating it with a solution consisting of from about 1 to about 4 /2 parts of glycerine and parts of commercial ethyl alcohol by applying to the paper more of such solution than sufficient to effect substantially complete saturation and mechanically removing the solution in excess of saturation, and then evaporating the alcohol from the paper.

RALPH ANZALONE.

(References on following page) REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 313,107 Ramsdell Mar. 3, 1885 748,179 Fowler Dec. 29, 1903 1,209,143 Gober Dec. 19, 1916 Number Number