US2540610A - Packing machine for molten materials - Google Patents

Description

Feb. 6,1951

Filed April 23, 1949 c. o. DAVIS ET AL PACKING momma FOR MOLTEN MATERIALS 2 Sheets-Sheet 1 IN VEN TORS CLYDE O. DAVIS and c. o. DAVIS ET AL PACKING MACHINE FOR MOLTEN MATERIALS Feb. 6, 1951 2 Sheets-Sheet 2 Filed April 23, 1949 IN VEN TORS CLYDE 0. DAVIS and By U WJWLNGS Patented Feb. 6, 1951 UNITED STATES PATENT OFFIQE 2,540,610 V PAcK ING MAonINE Fon MoLTEN MATERIALS v V Clyde Davis, Woodbury, and Uel P. Jennings,

Sewell, N. J., assfignors to E. I du Pont de Ne; mom-s & Company, Wilmington, Del., a corporation of Delaware Application April 2 3, 1949, Serials Io. 89,308

Claims.

, This invention relates to packing machines for molten or partially molten materia s, and particularly to packing machines for partially molten explosives, such as amatol (mixtures of ammonium nitrate and trinitrotoluene) and the like. In the manufacture of amatol eXDlosivejit 'is necessary to secure anintimate mixture of the ammonium nitrate and trinitrotoluene compo nents, and this is convenienty accomplished by incorporating molten trinitrotoluene with a suitable amount of crysta line ammonium nitrate in a jacketed mixer customarily referred was a grainer. Stirring of the solid. ammonium ni trate and the molten trinitrotoluene is continued for a suflicient timeto insure that a homogeneous mixture of trinitrotoluene-coated solidsis produced, whereu on the mixture is dischargedinto suitable containers and the mass is allowed, to cool to the solid state. Compositions within the range of 30-50% trinitrotoluene, the balance be ing ammonium nitrate are sufflciently fluid to permit ready pouring and casting into blocks and are therefore employed as blasting materials in the form of cylindrically shaped masses solidi fied within open-ended paper shells. The device of this invention comprises a machine for ack: i g the partially molten explosive into these cylindrical retaining shells. i An object of this invention is ,to provide a ma; chine for efficiently packing molten or partially molten explosive material into containers wherein the mass is cooled to the solid state. I Another object of this invention is to provide a machine for packing partially molten aniatol explosive with safety and dispatch. V Another object of thisinvention is to provide a portable packing machine for partia ly molten amatol explosive which may be rapidly, shifted from one loading area, in the plantto another; Other objects of this invention will become apparent from the detailed descriptionand the following illustrative drawings in whichi 4 Figure l is a side elevation view in partial "section of one embodiment, o

Figure 2 is a top plan view of the device shown in Figure 1, the overhead'portion of the rope retaining system being omitted for clarity of representation, V V

Figure 3 is a detailed View of the 'elevatingnut, Figure 4 is a perspective view showing one arrangement of the retaining rope and its guiding u e s Referring to Figure 1, the packing machine of this invention comprises a main rotatable screw member I mounted on a four-legged base 2 which isprovided with axles 3 and truck wheels 4 so that the device may be easily transported from one loading location to another. 7

Screw I is provided at its lower end with shouldersfor theaccommodation of bearings 5 and 6 which rotatably support i and carry the full weight of the screw and all of its appurtenances hereinafter described. The outerraces of bearings {rand 6 are housed within the flanges I and 8 of bearing housing 9 which is secured to base 2 by bolts I0. Screw I is provided with a circular @115; II fixedly secured thereto and machined with adownwardly disposed flange ,I2 which recesses within a peripheral groove in flange 1, sealingbearing housing 9 against the entrance of foreign material from the top end. Screw I is retained in position in base 2 by one or more individual bracket members l3 which extend over the outer edge of collar I I but which are normally out of contact therewith so that the brackets do not interfere with free rotation of the screw. The lower end 'of housing 9 is closed off by plate I4 secured bybolts I5 so that the full interior space may be packed with lubricant. o o

The four legs of base 2 are each provided with welded brackets I6 which support open annular draintank H for the collection of water drainingoff from the cooling table later described. Two adjacent legs of Zsupport an upstanding extension IQ to which restraining lever I3 is piv otally secured at its lower end by pin 29. The upper end of lever I9 is continually retained against the edge or serrations of indexing plate 2| by tension spring 22 (refer Figure 1), the inner end of which is connected to member 54 carried by a cross member of base 2. not shown. Support spider 23 may conveniently comprise four angle shapes fixedly secured at degree intervals, around the upper and lower flanges of upita fyelevating nut 24. As shown in detail in Figure}, the lower flange 25 of the. nut is internally threaded so that it is freely movable up or down on screw I when the screw is retained against rotation. If desired the upper flange may be similarly threaded; however, in the construction disclosed this has not been done since the lower flange has been designed sufficiently thick to provide enough thread area to carry the full weight load. Enough clearance is allowed between the upper flange of nut 24 and the outside surface of the threads of screw I to prevent binding therebetween and to permit nut 25 to pass freely up and down the shaft as vertical adjustments require.

Spider 23 carries cooling table 26 which may be securely welded thereto and is also provided with brackets 21 for the support of lower shell spacer 28 secured thereto by bolts 29.

Cooling table 26 is annular in shape and completely enclosed, the top and bottom plates defining it being separated a sufficient distance to form a hollow chamber 39 for the circulation of cooling water through its interior. This cooling water is continuously introduced from annular supply reservoir 3| through two flexible hose lengths 32, while warm water from chamber 3|] drains 01f into tank I! through a number of short flexible hose lengths 33, only one of which is shown. Water collecting in tank I! is led off to any conveniently located waste water building drain through hose 34.

Supply reservoir 3| is supported on four-legged spider 35 to which it is fixedly joined by welding or in any other convenient manner. Spider 35 is supported loosely on a shoulder of screw just above the threaded portion, the full weight of spider 35 and its appurtenances being carried by bearing plate 36 which is integrally joined to the spider legs, so that, with hoses v32 disconnected, the entire upper assembly may be lifted off if removal ever becomes necessary.

Upper spacer plate 31 and the four shell spacer uides 38 are secured to the lower arms of spider 35 by bolts 39. The lower ends of guides 38 engage with companion holes or slots (not shown) near the inner edge of lower spacer 28, so that the upper and lower spacers are always retained in the same relative positions with respect to one another regardless of the various positions taken by spider 23 in the course of its rotation. As shown in Figure l the coolingwater for the apparatus is supplied by a plant water line or extension 40 which is fitted with a valve 4| for adjusting the delivery rate.

As shown most clearly in Figure 2, upper shell spacer 31 is provided with a series of V-shaped serrations 42 around its periphery, eighteen in number being depicted, although it will be unde stoodthat a greater or lesser number may be provided, depending upon the degree of cooling required by the material which is being solidified and also upon the dimensions of the machine; Lower shell spacer 28 is provided with serrations 43 which are identical in size and number to the serrations of spacer 31 and are also always maintained in precise alignment therewith by guides 38.

Cylindrical paper shells 44, which are to be loaded with explosive, are retained in position by contact with the edges of serrations 42 and 43 and are restrained against outward displacement by endless rope 45.

Referring to Figures 1, 2 and 4, rope 45 is threaded around a series of guiding pulleys which maintains proper placement during loading op erations and at the same time keeps the rope taut. In Figure 4 the containers are represented as being cut off at the plane of rope contact to show more clearly the encircling relationship of rope 45, although in practice the rope is preferpage.

ably positioned at about the midpoint between the spacer plates, as shown in Figure 1, for best stability.

The rope pulley system is supported on a guide frame comprising upright angle shapes 35 and 41 which may be secured at their lower ends to adjacent legs of base 2 by welding or by suitable bolts. Cross piece 48 joined to the upper ends of the uprights provides additional strength and stiffness to the frame. Uprights and t! are slotted as shown at 49 in Figure l to permit vertical adjustment of single sheaves 5S and 5| to vary the level of rope contact with shells 44. The rope length is next threaded around single sheaves 52 and 53 and the two ends passed over double sheave 54, the free loop carrying block 55 provided with weight 56 which tensions rope 45 sufliciently so that the rope maintains shells 44 in firm engagement with serrations 42 and 63.

In operation, the machine is kept loaded with shells within the approximately 270 degree angle included by the lower reach of rope 45. Assuming that rotation of table 26 is in a clockwise direction as viewed from the top, the shells are successively positioned beneath the discharge funnel 5 of grainer kettle 58 as restraining lever I9 is manually engaged with the successive serrations 59 on the periphery of indexing plate 2|. The vertices of serrations 59 lie in the same radial plane as the vertices of serrations =32 and 43, so that engagement of lever l9 brings each of the several shells into precise location beneath the discharge funnel. In the embodiment described the friction of the threads of elevating nut 24 with screw is sufiicient so that there is no relative motion therebetween as tablezli is indexed to successive positions, and screw I therefore rotates with nut 24 without any slip- With constructions of lower weight it may be necessary to provide flange 25 and screw with a mating key and keyway to prevent unwanted vertical displacement between these elements during the course of table rotation.

As each of the shells 44 is presented to funnel 51, the machine operator opens discharge gate 60 by depressing lever 6| connected to bell crank 52, and fills the shells to the top level with the flu d explosive. The material at the bottom of the shells is thus'brought into direct contact with the cold surface of table 26, whereupon it instantly freezes into a solidified mass which prevents any molten material from leaking around the bottom edges of the container. This solidi- I fication process is continued as succeeding shells are filled during the following indexings so that,

when the shell finally reaches the point where the filled shells escape the restraint of rope 45,

and empty shells are loaded into the machine prior to the reimposition of rope restraint. During the rotation of table 26, drain hoses 33 are free to trail around the full length of tank ll, thereby continuously removing the water from chamber 30, which is concurrently replaced by cooler water supplied from tank 3|.

'Amatol explosive is requiredi-n packages of a number of difierent sizes to suit the particular requirements of the trade. The loading. machine of this invention is adapted to accommodate shells varying in outside diameter-from about 2 to about '8" and in length from about 6" to about 30" when spacer plate serrations of /2 radial depth are-utilized. Vertical adiustment for varying lengths is accomplished by restraining screw 1 against rotation while turning elevating nut 26 up or down the requisite distance to position the upper ends of the shells closely adjacent to the loading opening of funnel 51. This adjustment is facilitated by providing the top end of screw I with flats 63 for the engagement of a box wrench to prevent the rotation of l as elevating nut 24 is screwed up or down the threaded length by manual rotation of table 26. V

In explosives use all parts of the machine are preferably fabricated from non ferro-us metals, such as aluminum, brass or bronze, to safeguard against sparking hazards. Aluminum is particularly preferred for the cooling table, because the amatol will not stick to aluminum, and the danger of reaction of copper and ammonium nitrate is eliminated.

The device of this invention has proved highly practical in use. With two operators, it has been found that a production rate of 125 shells 4%" in diameter and 12" long can be readily maintained per hour without appreciable spilling of the fluid charge. Using the eighteen position machine described, approximately 1500 lbs. of explosive per hour may thus be loaded, the cooling time per shell being about 2% minutes in the course of the travel circuit from the filling funnel to the discharge point. 1

It will be apparent to persons skilled in the mechanical arts that this invention may be modified in a number of ways without departure from principle. Thus, in ome cases, only one spacer plate, located near the mid line of the containers, may be entirely satisfactory. Also, an elastic cord pinned to the uprights described may be substituted for the retaining rope, in which case the pulley system may be greatly simplified or even entirely eliminated.

It will be also understood that the machine of this invention may be Widely varied in arrangement and construction, wherefore we desire to be limited only within the scope of the appended claims.

We claim:

1. A packing machine for loading molten and partially molten explosive materials into containing shells comprising a base member, an upright rotatable screw supported within said base member, an annular cooling table threadedly engaged with said screw and normally rotatable therewith, a first locating means rotatable with said table for retaining the lower portions of. saidshell against radial inward movement with respect to said table, a second locating means rotatable with said table and in vertical alignment with said first locating means for retaining the upper portions of said shells against radial inward movement with respect to said table, flexible means integral with said machine for retaining said shells in contact with both of said locating means, and means for passing a coolant through said cooling table to thereby solidify the filling at the bottom of said shells and prevent any substantial leakage therefrom.

2. A packing machine for loading molten and partially molten explosive materials into containing shells comprising a base member, an up- 7 right rotatable screw supported within said base member, an annular cooling table threadedly engaged with said screw and normally rotatable therewith, said cooling table being provided with an interior channel for'the circulation of coolant therethrough and meansfor the supply of coolant to and the withdrawal of ooolantfrom said table, a first locating means rotatable with said table for retaining the lower portions of said shells against radial inward movement with respect to said table, a second locating means rotatable with said table and in vertical alignment with said first locating means for retaining the upper portions of said shells against radial inward movement with respect to said table, and flexible means integral with said machine for retaining said shells in contact with both of said locating means.

3. A packing machine for loading molten and partially molten explosive materials into containing shells according to claim 2 wherein said flexible retaining means comprises a continuous tightly drawn rope the shell restraining'reach of which is supported by vertically adjustable pulleys while the remaining length is led away from contact with said shells by other pulleys so that, during at least a portion of said cooling tables rotation, said shells will be released from inward radial restraint.

4. A packing machine for loading molten and partially molten explosive materials into containing shells comprising a base member, an upright rotatable screw supported within said base member, an annular cooling table threadedly engaged with said screw in such a manner that rocation of said table turns said screw without substantial relative movement therebetween when said screw is free from extraneous restraint, said cooling table being provided with an interior channel for the circulation of coolant therethrough and means for the supply of coolant to and the withdrawal of coolant from said table, a first locating means rotatable with said table for retaining the lower portions of said shells against radial inward movement with respect to said table, a second locating means rotatable with said table for retaining the upper portions of said shells against radial inward movement with respect to said table, guiding means maintaining said first locating means in vertical alignment with said second locating means, and flexible means integral with said machine for retaining said shells in contact with both of said locating means.

5. A packing machine for loading molten and partially molten explosive materials into containing shells comprising a base member, an upright rotatable screw supported within said base member, an annular cooling table threadedly engaged with said screw in such a manner that rotation of said table turns said screw without substantial relative movement therebetween when said screw is free from extraneous re-- 8 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Guion Feb. 22, 1887 Cline May 13, 1890 'Lewin May 16, 1933 Davis et al Apr. 9, 1935 Fritz Aug. 20, 1935

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