The parachute is made of light, tough Japanese paper. The thickness of the paper is not unlike that of the rice paper used for cigarettes. The parachute is composed of seven sectors, the length of a sector being 16 inches with an arc approximately 12 inches. These sectors are sewn together with a fine cotton or fiber thread. The parachute strings are tied to the ends of the seam. When completely assembled the parachute has a form not unlike that of an open umbrella; often with an inverted cone at the center, due to the drawing forward of the central parachute strings which are attached to the apex of the parachute. There are eight parachute strings, seven of them extending from the seams where the sectors are sewn together and the eighth being attached to the center or focus of these seams. The strings are knotted together at a distance permitting the free opening of the parachute.
Fig. 148. - Introduction of light into shell.
Figure 134 shows a parachute which has opened and is functioning properly, having been expelled from its case.
It is obvious that careful and delicate manipulation in packing is necessary in order to insure the opening of the parachute in a proper manner so that the strings will not become entangled, thus preventing the proper functioning of the article. There is no standard method of folding the parachute, each manufacturer following his own plan, which accordmg to his experience has given the best result. There is, however, a general procedure which is shown in figures 149 and 150.
Fig. 149. - Plaiting folds of parachute.
First the parachute is inspected for imperfections. This is done by the operator's drawing the parachute quickly through the air by means of the strings, thus inflating it and giving it a test. The perfect parachutes are then rubbed thoroughly inside and out with pulverized pumice stone.
This is necessary in order that the parachute shall open smoothly when expelled from the container.
The next operation is to tie the parachute strings to the asbestos cord. The operator before tying the strings again inspects the parachute in a manner similar to that which has been described above. The asbestos cord is now tied to the parachute strings by simple knots. The parachute is then ready for folding and the operator doing this work again inspects it in the same manner as above.
Fig. 150. - Folded parachuate.
The operator holds a parachute at its apex, and first runs his fingers as a comb downward through the strings to see that they are not entangled. The seams of the various segments are drawn and accordeon plaited, very much in the manner of an umbrella folded before being rolled.
The parachute is encircled by the hand and the folds smoothed down into a cylindrical form and then folded double. The strings are now caught up and coiled around three fingers of the hand and the coil is placed against the side of the folded parachute. After the strings have been carefully arranged the bundle is again folded over the strings, making a compact package, which is shown in figure 150, ready to be inserted into the case.
This is a compressed cork disk 1 3/4 inches in diameter by 3/8 inch thick, which is forced into the top of the shell to hold the contents in place.
Fig. 151. - Cork cap.
This is a stamped-tin disk with several prongs which are forced into the cork cap after it has been inserted into the container. This disk is shaped and painted to designate the color of the light as follows:
Fig. 152. - Identification cap assembled.
Indented indicates white; smooth crown shape, green, and corrugated, red.
The blank cartridge used for the rifle light consists of the ordinary 30-caliber supplied with a reduced charge. Each rifle light has a blank cartridge attached to its side, so that men in the field do not have to be supplied with a special cartridge in order to fire the rifle lights. Figure 129 shows the arrangement of cartridge banded to the side of the rifle light.
This consists of a 1 1/4- by 1 3/4-inch strip of 30-pound Kraft paper, which encircles the cartridge to protect it from becoming gummed up with the adhesive tape used to bind it to the rifle light.
This consists of 1/2-inch-wide electrician's adhesive tape, 8 inches long, and serves to hold the cartridge to the light-case shell.
Rifle lights are packed in cardboard cartons, six lights per carton. Figure 153 shows the method of packing the carton. These carton9 when filled are sealed with gum paper and dipped in molten low-grade paraffin. Five cartons are dipped per charge.
The packing cartons are then packed in a shipping carton, measuring 6 by 6 3/4 by 23 inches and carrying five packing cartons, it, too, being sealed with gum paper and dipped in molten crude paraffin.
Fig. 153. - Packing carton and designating caps.
Plate 8. - Parachute-rifle-light flow sheet.
Plate 9. - Parachute-rifle-light material chart.