US2600530A - Packing machine for powder materials - Google Patents

Description

J1me 1952 G, c. GRIFFIN ETAL PACKING MACHINE FOR POWDER MATERIALS 2 SHEETS-SHEET 1 Filed March 22, 1951 June 1952 G. c. GRIFFIN ETAL PACKING MACHINE FOR POWDER MATERIALS 2 SHEETS-SHEET 2 Filed March 22, 1951 Patented June 17, 1952 UNITED STATES PATENT OFFICE PACKING MACHINE FOR POWDER MATERIALS Application March 22, 1951, Serial No. 217,004

Claims.

This invention relates to a machine for packing or tamping nonfree flowing powders and more particularly to a mechanical packer for loading explosive dynamite powders in large size dynamite cartridges.

Large size dynamite cartridges may vary anywhere from 2 to 8 inches in diameter and from 8 to 21 inches in length. For example, cartridges typical of the class are as follows: 4 x 16 inches, 5 x 16 inches, 8 x 21 inches, etc. This type of cartridge is used principally for quarrying, open pit blasting and to some extent in tunnelling. Ammonia dynamites, semi-gelatins and straight dynamites are customarily used to fill these cartridges. These explosive materials are powdery or granular in physical appearance but are not free flowing. In the filling operation it is necessary that each cartridge have a definite weight of explosive, and further that the cartridge be sufficiently rigid to withstand tamping into shot holes. To accomplish these requirements, tamping or packing of the powders becomes an essential part of the filling operation.

Tamping of small size dynamite cartridges, viz., 1%; x 8 inches, by use of vertical tamping machines such as the Hall machine, described in U. S. P. 1,031,644, never became a problem. However, with the introduction of the large size dynamites, the Hall machine was useless, and hence the loading and tamping had to be done by hand, i. e., the empty paper shell was set in a holder, fitted with a funnel, filled with the explosive mixture and tamped with a wooden tamping stick to the required density. Aside from the fatiguing effect of hand tamping and the constant exposure to fumes of E. G. D. (ethylene glycol dinitrate) the method has the main disadvantage of being too low for commercial production. Many mechanical devices have been introduced in order to overcome this problem. One type of machine, known as a vibrating packer, utilized ultra high frequency oscillations as the shaking medium. The packer resulted only in settling powders of the type described, and was completely useless for proper tamping of large size dynamite cartridges. A large size semi-automatic packer known as a Kimber machine and described in U. S. P. 813,435 utilized a horizontal multiple series of tamping sticks, but was extremely costly to build, required numerous safety precautions in its operation. and was expensive to maintain in mechanical repair. Air-actuated shakers were unsatisfactory for the purpose due mainly to air line pressure fluctuation and consequent velocity changes of the shaking mechanism. Auger packers, utilizing a spiral worm type feed, were considered unsafe for handling explosive powders.

It is an object of this invention to provide a low cost mechanical means for packing nonfree flowing powders into container shells.

Another object of this invention is the production of a low cost mechanical packer for tamping explosive dynamite powders in large size dynamite cartridges.

The objects of the present invention are accomplished by the use of a jolting type packer positively driven off a rotating crankshaft to a reciprocating piston which operates at a frequency critical for efficient filling and maximum tamping action.

Essential parts of our packing machine are more apparent by referring to the accompanying drawings in which:

Figure 1 is a side elevation of the packer showing a partial section of a dynamite cartridge in its holder during the upward stroke of the machine;

Figure 2 is a top elevation of the hopper supporting bracket taken along the line 2, 2 of Figure 1.

Referring in greater detail to Figure 1 of the drawings, shell platform I is supported by metal plate 3 and attached thereto by wood screws (not shown). Metal plate 3 is removably attached to head of piston 4 by means of hexagon nut 2. Cover plate 21 is removable for access to hexagon nut 2. Shell i normally rests freely without at tachment of any kind in holder 8 which is removably attached to base pad 6. The base pad Ii is separated from direct contact with shell platform i by resilient rubber layer I. Draw bolts 9 maintain attachment of shell base pad 6 to shell platform I. Shell holder 8 is replace able for holders of varying diameters depending upon the size of shells being loaded.

Piston 4 moves through sleeve iii and is attached to connecting rod II by means of wrist pin l 2. crankcase 38 houses crankshaft i3 which rotates in main bearings I i. Connecting rod II is driven by crankshaft l3 through crankshaft bearing l5. Counterbalanced flywheel I6 is connected to an extension of crankshaft I3 located outside of crankshaft 38. Lubrication of crankshaft and main bearings is accomplished by maintaining a minimum level of oil in crankcase 38. Casing 34 encloses the driving mechaanism of the packer. Rubber bellows l1 extending between metal plate 3 of reciprocating shell platform i and stationary piston housing it acts to keep any powder out of contact with the movable mechanism.

A superstructure for shell platform 1 comprises a. rubber covered ring and support rods l9, the latter adjustable for height by means of adjusting nuts 2| and lock nuts 22. A hopper funnel is inserted through a substantially circular opening made in panel 33 of a hopper supporting bracket 23, and is maintained in rigid attachment with the latter by means of adjustable bolts 26. One end of hopper supporting bracket 23 is pivoted at hinge 24, with the opposite end contacting ring 20 at panel 33 on the upward stroke of ring 20. A holder 28 for hopper supporting bracket 23 is pivoted from ceiling at hin e 29 and serves to block bracket 23 out of contact with ring 20 during a change of shell 5. Mouth of hopper funnel 25 faces one side and is framed with resilient rubber padding 3|. A rubber sleeve 32 circles the neck of hopper funnel 25 at a point where it contacts circular opening in panel 33 of hopper supporting bracket 23. Additional rubber padding not shown in the drawings is placed on the underside of panel 33 in hopper bracket 23 at a point where it rests on ring 20 when bracket is lowered to the operating position.

In operating the packer of our invention an empty shell 5 is placed in shell holder 8 where it is free to bounce in a vertical direction when the machine is set in operation. Holder 28 is moved outwardly releasing block from one end of hopper bracket 23 thus permitting the latter to swing downwardly and the neck of hopper funnel 25 to enter the open end of shell 5. The depth to which the neck of hopper funnel 25 enters shell 5 determines the level to which shell 5 may be filled with the explosive powder. This level is adjustable for shells of varying lengths and diameters by adjusting nuts 2| and replacing shell holder 8 with a holder of the desired diameter. The machine is now set in operation and the explosive powder introduced into hopper funnel 25. The rotary cranking motion of crankshaft I3 through connecting rod ll imparts a reciprocating movement to piston 4 and thus shell platform I moves with a reciprocating type action. This action is utilized in two ways. In the first place, the reciprocating action of shell platform I causes powder 31 to be tamped in shell 5 and secondly, this action is utilized to pound at hopper funnel 25 through ring 20 and so prevent clogging of the explosive powder to the sides and neck of the hopper funnel 25. When the level of the powder in shell 5 reaches the narrow neck of hopper funnel 25 the continued jolting action causes a plug of the powder to form at the very end of the neck. As soon as hopper bracket 23 is lifted out of ring 2|] for the purpose of inserting a new shell 5 this plug acts as a stopper preventing additional powder in hopper funnel 25 from flowing out the neck of the funnel. When the hopper bracket 23 is again lowered and the ring 20 which is still in motion contacts the bracket, the jolting action frees the plug and the powder continues to flow into empty shell 5. In practice the machine is never stopped between changes of shells.

The principle of the tamping action achieved by the packer of our invention depends upon the fact that the upward movement of shell platform I shown by the arrow in Figure 1 of the drawings, attains a higher velocity than the rate of acceleration of the shell downward due to gravity. Thus shell platform I completes a downward stroke and has started on the upward stroke when it again meets the shell which is still falling. The effect of this action results in an intermittent upward whacking or jolting force applied to the base of the shell, thus causing the powder contained therein to pack to a greater density. It is a critical part of this invention therefore that the shell be free to bounce within its holder, a practice which is the exact reverse to what has been used heretofore, where the containers to be filled were rigidly attached to the platform or holder carrying them.

It is evident from the above description of the principle of the tamping action in the packer of our invention, that the speed at which the shaker is driven for the range of shell weights being tamped is also a critical factor in attaining proper tamping of the shell. Associated with the speed factor, but to a lesser degree, is the length of stroke of the piston of our packer. We have discovered that proper tamping of these cartridges is assured only when the packer operates at a speed of 300 R. P. M. and a piston stroke of 1 ,1 inches. A variation of more than 2 from these figures results in unsatisfactory tamping results.

At a speed of 300 R. P. M. and 1 inch piston stroke we have been able to pack 4 x 16 inch dynamite cartridges at the rate of 4 cartridges per minute. Using former hand tamping methods this rate drops to about 1 cartridge per minute maximum. Thus a substantial increase in the rate at which these cartridges are produced must be attributed to the use of our packer. With the smaller diameter large size cartridges, as many as 4 cartridges can be tamped simultaneously. The only change necessary is to replace the hopper funnel 25 with a smaller 4-necked funnel which fits the open ends of the smaller diameter cartridges.

While the method of driving the packer of our invention is not shown in the figures of the drawings, many methods are available. We have found the use of a 1; H. P. electric motor with suitable reduction through V-belt drive to a pulley located on extension of crankshaft 13 to be entirely satisfactory.

In the operation of our packer using the embodiment shown in Figure 2 of pivoting hopper bracket 23 from a side wall, we hav found it necessary to maintain some counter-balancing means to prevent the hopper bracket 23 from bouncing too high off the rubber coated ring 20. A simple means of accomplishing this is to have the operator place his hand on this end of the bracket during the filling of the shell. The use of a circular tension spring mounted at the hinge end of the hopper bracket 23 is also satisfactory. A further embodiment of hopper bracket 23 not shown in th drawings but indicated in Figure 2 thereof, is to have a. part of the bracket suspended from the ceiling directly above hopper funnel 25 instead of being pivoted to a side wall. Such an arrangement contemplates cutting bracket 23 along the line A, B and attaching the left portion from points 35 and 36 to a standard peg and slot arrangement at the ceiling. This provides the necessary travel of the hopper holder in a vertical direction. In this instance the weight of the bracket and hopper funnel 25 acting directly downwards is sufficient to overcome the tendency of the bracket to bounce too high from ring 20.

While a hand method of feeding explosive powder into hopper funnel 25 has been illustrated for th present form of packer, it is within the spirit of this invention to use other means such as a conveyor belt feed for filling the cartridges to be tamped.

It would be an obvious improvement of the present invention to adapt the packer to a multiple scale in which a battery of shakers having individual drive, but a common feed system, is contemplated.

It i to be understood that the scope of the present invention is not limited to the details specifically set forth in this disclosure, wide vari ations therein being possible without departing, from the spirit of the invention.

Having thus described our invention what we claim is:

l. A packing machine for loading and tamping non free flowing explosive materials into container shells, which comprises a base member, a crankshaft normally rotatable and supported within said base member, a connecting rod eccentrically driven from said crankshaft, a piston attached to one end of said connecting rod, a shell platform threadably engaged with the head of said piston and movable therewith, a holder for said shell detachably mounted on said platform permitting fre vertical movement of said shell, at least two rods threadably attached to said platform and supporting a ring structure, a movable hopper supporting bracket normally contacting said ring structure, a hopper funnel lo cated in an aperture in said supporting bracket, the neck of said hopper funnel passing through said ring structure, and mechanical motor means for applying rotary movement at a predetermined rate to said crankshaft.

2. A packing machine for loading and tamping non free flowing explosive materials into container shells, which comprises a base member, a crankshaft normally rotatable and supported within said base member, a connecting rod eccentrically driven from said crankshaft, a piston attached to one end of said connecting rod, said piston reciprocating at a speed of between 285 and 315 revolutions per minute with a 1 inch stroke, a

shell platform threadably engaged with the head of said piston and reciprocating therewith, a holder for said shell detachably mounted on said platform and permitting free vertical movement of said shell, at least two rods threadably attached to said platform and supporting a ring tructure, a movable hopper supporting bracket normally contacting said ring structure, a hopper funnel located in an aperture in said supporting bracket, the neck of said hopper funnel passing through said ring structure, and mechanical motor means for applying rotary movement at a predetermined rate to said crankshaft.

3. A packing machine for loading and tamping non free flowing explosive materials into container shells, which comprises a base member, a crankshaft normally rotatable and supported within said base member, a connecting rod eccentrically driven from said crankshaft, a piston attached to on end of said connecting rod. said piston reciprocating at a speed of 300 revolutions per minute with a 1 inch stroke, a shell platform threadably engaged with the head of said piston and reciprocating therewith, a holder for said shell detachably mounted on said platform and permitting free vertical movement of said shell, at least two rods threadably attached to said platform and supporting a ring structure, a movable hopper supporting bracket normally contacting said ring structure, a hopper funnel located in an aperture in said supporting bracket, the neck of said hopper funnel passing through said ring structure, and mechanical motor means for applying rotary movement at a predetermined rate to said crankshaft.

4. A packing machine for loading and tamping non free flowing explosiv materials into container shells, which comprises a base member, a crankshaft normally rotatable and supported within said base member, a connecting rod eccentrically driven from said crankshaft, a piston attached to one end of said connecting rod, a shell platform threadably engaged with the head of said piston and movable therewith, a holder for said shell detachably mounted on said platform and permitting free vertical movement of said shell, at least two rods threadably attached to said platform and supporting a ring structure, a movable hopper supporting bracket normally contacting said ring structure, one end of said hopper supporting bracket pivoted to a vertical support, a hopper funnel located in an aperture in said supporting bracket, the neck of said hopper funnel passing through said ring structure, and mechanical motor means for applying rotary movement at a predetermined rate to said crankshaft.

5. A packing machine for loading and tampina non free flowing explosive materials into container shells, which comprises a base member, a crankshaft normally rotatable and supported within said base member, a connecting rod eccentrically driven from said crankshaft, a piston attached to one end of said connecting rod, a shell platform threadably engaged with the head of said piston and movable therewith, a holder for said shell detachably mounted on said platform and permitting free vertical movement of said shell, at least two rod threadably attached to said platform and supporting a ring structure, a movable hopper supporting bracket normally contacting said ring structure, said hopper supporting bracket attached to a horizontal support and in vertical alignment with said ring structure, a hopper funnel located in an aperture in said supporting bracket, the neck of said hopper funnel passing through said ring structure, and mechanical motor means for applying rotary movement at a predetermined rate to said crankshaft.

GRANT CORBIN GRIFFIN. WALTER GEORGE IVANY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 218,658 Bolton et a1 Aug. 19, 1879 469,992 Cox Mar. 1, 1892 993,230 Englen May 23, 1911 1,872,686 Cundall Aug. 23, 1932

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