US3266531A - Frictionless loading method and apparatus - Google Patents

Description

Aug. 16, 1966 w. M COWN, JR 3,266,531.

FRICTIONLESS LOADING METHOD AND APPARATUS Filed March 25, 1964 5 Sheets-Sheet l I A l" M/VE/VTQ/P JAMES W. Me COWN, JR.

ATTORNEY Aug. 16, 1966 w ccow JR FRICTIONLESS LOADING METHOD AND APPARATUS Filed March 25, 1964 5 Sheets-Sheet 2 lA/VE/VTOR JAMES 14 McC'OW/V. JR.

MMW

ATTOR/VEV Aug. 16, 1966 J. w. M COWN, JR

FRICTIONLESS LOADING METHOD AND APPARATUS Filed March 25, 1964 5 Sheets-Sheet 3 TIMER LOADEI? CIRCUIT COMPENSAT/A/G C/RCU/T ATTORNEY 3,256,531 FRIIITIGNLESS LGADING lt IETI-IUD AND APPARATUS Barnes W. hIcCown, .Iiz, Iexarirana, Tern, assignor to Day & Zimmermann, Inc, Ihiiadelphia, Pa, a corporation of Maryiand Filed Mar. 25, 1964, Ser. No. 354,539 15 Ciairns. (@l. 141-1) This invention relates to a compensating frictionless loading apparatus, and more particularly, to a loading apparatus for explosives in powder or liquid form.

I-Ieretofore, all of the explosive powder loaders that I am familiar with were provided with frictional inducing surfaces, pinch points, unavoidable pressures, etc. Such loaders are inherently hazardous, especially when the powder is sensitive, such as lead azide, RDX, etc. The present invention provides a frictionless loader in the sense that there are no frictional inducing surfaces or pinch points to create a hazard and a potential explosion during loading operations.

When the powder to be loaded is disposed in a hopper, there wiil be bridging over of the powder in the throat of the hopper when flow is shut off. Whenever any means is provided to shut off the flow, such as a valve or the like, there is created a friction or pinch point which is a potential hazard. To overcome this objectionable feature, the present invention provides a hopper wherein the powder is permitted to freely flow therefrom without interruption. In a given length of time, a given amount of powder will have been discharged from the hopper into a receptacle. A control means is provided to intermittently interrupt the discharge of the flow of powder into the receptacle and divert the same to a return means which returns the powder back into the hopper. By returning the powder back into the hopper, the additional benefit of reblending of the powder is obtained.

The loader is adapted to be utilized in conjunction with any conventional loading press having a loading ram for compacting the powder in its receptacle. A timing means is provided so that the interruption or diversion of the flow from the hopper is effected in timed relationship with respect to the placing of a receptacle to receive powder from the hopper and the stroke of the loading ram. Thus, a change will be necessitated in the timing of the diversion of powder from the hopper as dictated by the height of compressed powder in the receptacle. If the compressed height of powder in the receptacle is Within normal tolerances, no changes are effected by the timing means. If the height of the compressed powder is above or below an acceptable level, a change is effected in the timing means to compensate for the high or low levels detected.

It is an object of the present invention to provide a novel loading apparatus.

It is another object of the present invention to provide a novel loading apparatus for powdered material.

It is another object of the present invention to provide a novel apparatus and method for loading powder explosives.

It is another object of the present invention to provide an explosive loading apparatus wherein powdered explosive is continuously discharged from a hopper and reblending of powder is attained by recirculating a portion of the discharged powder back into the hopper.

It is another object of the present invention to provide a loading apparatus having structure for synchronizing operation of the apparatus in conjunction with the detection of acceptable production at a consolidating station of the powder.

It is another object of the present invention to provide a novel loading method.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a front elevation view of loading apparatus in accordance with the present invention, with parts broken away for clarity of illustration.

FIGURE 2 is a sectional view taken along the line 22 in FIGURE 1.

FIGURE 3 is a sectional view taken along the line 33 in FIGURE 2.

FIGURE 4 is a sectional view taken along the line 44 in FIGURE 1.

FIGURE 5 is a sectional view taken along the line 55 in FIGURE 4.

FIGURE 6 is a schematic diagram.

FIGURE 7 is a schematic wiring diagram.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIGURE 1 a loading apparatus designated generally as 10. The apparatus 10 is disposed within a metallic housing 12 which is open at its top to atmosphere at a point above the roof of the building. Hence, any explosions within the housing 12 will be directly channeled upwardly through the roof of the building to the atmosphere. The housing 12 is provided with a selectively operable door 14- in any convenient manner.

Within housing 12, there is provided a horizontally disposed base plate 16. Base plate 16 supports a mounting plate 18. As shown more clearly in FIGURE 3, a mounting block 20 is provided on the plate 18 and adjustably positionable with respect thereto by means of the slotted opening through which threaded bolt 22 is secured.

A support member 24 is pivotably secured to the block 20 for pivotable movement about the longitudinal axis of pin 26. Support member 24 is provided with an upstanding wall 28 having an aperture therethrough. A mounting ring 30 is secured to the upper end of wall 28 in any convenient manner.

The mounting ring 30 is provided with a flat upper surface and a tapered aperture extending therethrough. Ring 30 receives and supports a hopper 32. Hopper 32 is conical and is provided with a controlled dimension at its throat 33. The flow passage below the throat 33 tapers radially outwardly on the hopper 32. It is within the scope of the present invention to provide a removable disk at the throat 33. A plurality of such disks may be utilized with different sized holes therethrough. When pouring explosives, it is advisable to substitute an entirely new hopper when changing from one explosive to another.

A funnel 34 is disposed below and spaced from the lower end of the hopper 32. Funnel 34- is provided with a reduced diameter portion which is disposed within the aperture 36 in the plate 18. A U-shaped notch is provided in one wall of funnel 34 for a purpose to be described hereinafter.

The mounting ring 30 is provided with a flange 38. A power cylinder is removably coupled to the flange 38 by means of bracket 39. A motive fluid, such as air, is capable of being introduced into the cylinder 40 by way of conduit 42. A piston is disposed within the cylinder 40 and adapted to be biased by the motive fluid downwardly and to the left in FIGURE 3. During such movement of the piston, spring 41 is compressed. When the pressure of the motive fluid is relieved, the spring 41 expands and returns the piston to its initial position.

A piston rod 44 is connected to the piston disposed within cylinder 4G. The end of piston rod 44 remote from the piston is movably and adjustably coupled to a shuttle 46. The shuttle 46 is U-shaped in transverse cross section as shown more clearly in FIGURE 2. The shuttle 46 is provided with an aperture 48 which is in line with the throat 33 in the discharging position of the shuttle 46. Thus, in this position of the shuttle 46, powder will be discharged from the throat 33 directly through the aperture 48 and through the funnel 34.

A recirculating means generally designated as 50 is provided to receive powder diverted by the shuttle 46 and return the same to the hopper 32 thereby effecting a reblending of the powder. Such recirculating means includes wheel 52 in the general form of a truncated cone. Wheel 52 has a rim 54 defined by an axially extending Wall and radially inwardly directed parallel walls, one of which terminates in a radially inwardly tapered tip 58. Within the rim 54, there are provided a plurality of pockets 56. As shown more clearly in FIGURES 2 and 3, the rim 54 is of such a size and is positioned in a manner so that it may receive powder from the shuttle 46 and convey the same through an arc of approximately 180 degrees at which point the powder collected will be returned into the hopper 32.

The wheel 52 is provided with a hub 60. Hub 60 is removably coupled to one end of shaft 62. Shaft 62 extends through opposite walls of a housing 66. A gear 64 is secured to the shaft 62 and is in meshing engagement with a worm 72. Worm 72 is tangent to the gear 64 and connected to one end of a pneumatically rotated shaft.

The housing 66 is connected by flanges and bolts to a standard 68. Standard 68 is provided at its lower end with a base 70 removably coupled to the mounting plate 18. At its upper end, the standard 68 is provided with a plate 73 which has an aperture through which the shaft for the worm 72 extends. Said last-mentioned shaft extends into a pneumatic motor 74. Said shaft is in effect the output shaft for transmitting rotary motion from the motor 74. A hydraulic or electric motor could be used in lieu of the pneumatic motor 74 if desired.

As shown more clearly in FIGURE 1, a support plate 76 is supported by the housing 12 below the base plate 16. A table 78 is rotatably supported by hearings on the plate 76 and coupled to a gear reducer 82 of the motor 80. Motor 80 rotatably drives the table 78 to intermittently position a primer cup 79 or the like below an aperture in the plate 16 which in turn is in line with and below the reduced diameter portion of the funnel 34. The table 78 may be provided with pockets into which the primer cups are disposed.

As shown more clearly in FIGURES 1, 4 and 5, a timer housing 84 is provided. Housing 84 is provided with a removable cover 86 having a transparent window 88 therein. A partition 90 is removably supported within the housing 84 by means of brackets. A shaft 87 extends through the partition 90 and has a gear 89 coupled to one end thereof between the partition 90 and the cover 86.

A portion of the high and low compensating circuits are adapted to cooperate with the gear 89 to rotate the same incremental amounts in opposite directions. Such portions are identical. Accordingly, only the portion of the high compensating circuit will be described in detail with corresponding primed numerals provided for the corresponding structure of the low compensating circuit.

A pawl 91 is supported for contact with the gear 89 to rotate the same in a counterclockwise direction in FIGURE 4. Pawl 91 is supported by piston rod 92 which extends through a bushing 95. Piston rod 92 is coupled to a piston within cylinder 93. The last-mentioned piston is spring biased upwardly in FIGURE 4. A motive fluid, such as air, may be introduced through conduit 94 to bias the piston downwardly against the spring pressure to move the pawl 91 into contact with the gear 89. A single action solenoid may be used in lieu of the air operated cylinder 93. An adjustable limit stop 96 is provided on the partition to limit the stroke of the piston rod 92.

The shaft 87 is an integral part of an adjustable potentiometer 98 supported by the shaft 87 on the opposite side of the partition 90 from the gear 89. Within the housing 84 to the left of the partition 90 in FIGURE 5, there will be housed numerous components of an electrical circuit including relays, switches, and the like which will be described hereinafter.

In FIGURE 6, there is illustrated a compensating circuit 99 and a loader circuit 100 in diagrammatic form. Circuit 99 includes microswitches 108 and 110. Switch 108 will be actuated by the consolidating ram of the press for compacting the powder within the primer cup 79. Switch 108 is adapted to be actuated when the amount of powder within the cup 79 is in excess of a permissible limit or range. Switch 108 is coupled to a solenoid 104 which controls a valve in the conduit 94.

When solenoid 104 is actuated, air or other motive fluid will flow through conduit 94 into cylinder 93 to effect rotation of the gear 89 in a counterclockwise direction in FIGURE 4 to thereby adjust the potentiometer 98 in one direction. A low limit microswitch 110 is adapted to be actuated when the compressed powder is below the permissible limit or range. In a similar manner, switch 110 will operate solenoid 106 which will control the flow of air or other motive fluid through conduit 94 to effect rotation of the gear 89 in a clockwise direction in FIGURE 4 to thereby adjust the potentiometer 98 in an opposite direction.

The contact terminals of the potentiometer 98 are coupled to a solid state timer 148. When actuated, timer 148 operates relay 102 which in turn controls activation of solenoid 116. Solenoid 116 controls the flow of air or other motive fluid through conduit 42 to effect movement of the shuttle 46 against the pressure of spring 41. In FIGURE 6, the wheel 52 and hopper 32 are diagrammatically illustrated.

In FIGURE 7, there is illustrated a schematic Wiring diagram. A load is coupled by Way of conductors 118 and 120 to the terminals of a source of electrical power such as a volt A.C. 60 cylce single phase source. Conductor 118 is provided with an on-off switch 124. Conductor 126 extends between the conductors 118 and and contains a high manual normally open switch 128 and the solenoid 104. Conductor 130 extends from conductor 118 to a terminal for switch 108.

A manual normally open switch 134 is provided in conductor 136 coupled across conductors 118 and 120. Conductor 136 contains solenoid 106. A switch 110 is coupled across conductors 130 and 136. Switch 110 is a microswitch responsive to a low charge in the receptacle such as a primer cup.

A conductor 138 is coupled across conductors 118 and 120 and contains solenoid 116, the switch 140 operated by a solenoid 102, and switch 142. Switch 142 is one-half of a double pole switch of which switch 114 is the other half. A solid state timer 148 is coupled across the conductors 118 and 120 by conductors 144 and 146, connected respectively to the contacts 2 and 3 on the timer 148. It will be noted that the potentiometer 98 is coupled across contacts 4 and 5 on the timer 148. The solenoids 104 and 106 are coupled to the pointer of the potentiometer 98 to increase or decrease the resistance between contacts 4 and 5 as alluded to above and as will be explained hereinafter. Switch 114 is coupled across contacts 7 and 8 of the timer 148. The solenoid 102 is coupled across the contacts 1 and 9 of the timer 148.

In the timer 148, contacts 3 and 4 are coupled together, contacts 4 and 7 are coupled together, contacts 8 and 9 are coupled together, and contacts 1 and 3 are coupled together.

Operation of the structure described heretofore, assuming switch 124 is closed and wheel 52 is rotating, is as follows:

Powder is continuously permitted to discharge through the throat of the hopper 32. With the shuttle 46 in the position illustrated in FIGURE 3, such powder passes through the aperture 48, through the funnel 34, through the aperture in plate 16 into a receptacle such as a detonator or primer cup 79 disposed therebelo'w. After a predetermined interval of time, timer 148 times out whereby solenoid 102 is energized to open switch 140 thereby deenergiz'ng solenoid 116.

When solenoid 116 is deenergized, the pressure of the motive fluid on the piston in cylinder 40 is removed whereby the spring 41 expands and moves the shuttle 46 to an inoperative position. In the inoperative position of the shuttle 46, the aperture 48 is to the right of a straight line extending from the throat 33 to the aperture 36. Hence, all powder discharged from the throat 33 into the shuttle 46 will be transferred by gravity into one of the pockets 56 on the continuously rotating wheel 52. Thereafter, such powder will be discharged from its respective pocket back into the hopper 32. The amount of powder which flows from the throat 33 through the aperture 48 is a function of time since the flow rate is continuous. As soon as the next cup 79 is positioned to receive powder, switches 114 and 142 will have been mechanically actuated to a closed position by an element of the loading press. For example, on a Jones loading press, such element may be a part of the Geneva movement device. Since switch 140 is normally closed, solenoid 116 will be energized. When solenoid 116 is energized, the valve controlling flow in conduit 42 will be open whereby motive fluid such as air will be introduced into cylinder 40 to reciprocate shuttle 46 to the position illustrated in FIGURE 3.

Immediately following the station where an increment of powder is dispensed as described above, there is a press consolidating station wherein the powder is consolidated to a required pressure. At this station, there is provided high limit microswitch 108 and low limit microswitch 110 which are actuated by the consolidating ram when the compressed powder height is outside of a predetermined range. As long as the compressed powder height is maintained within a predetermined range, acceptable production is being accomplished and neither switch 108 nor 110 is activated. If the compressed powder height is so high as to be outside the acceptable range, switch 108 is activated to effect energization of solenoid 104.

When solenoid 104 is energized, motive fluid such as air is permitted to flow through conduit 94 into cylinder 93 to move the piston rod 92 and pawl 91 downwardly in FIGURE 4. Such downward movement of the pawl 91 rotates the gear 82 in a counterclockwise direction in FIGURE 4 thereby decreasing the resistance in the potentiometer 98. Such decrease in the resistance of potentiometer 98 dezrea es the time interval for the energization of solenoid 116 which in turn decreases the time interval wherein the shuttle 46 is in the position shown in FIGURE 3. As a result thereof, the amount of powder discharged into the primer cup is decreased.

If the compressed powder height is below the predetermined range, switch 110 will be activated which in turn will energize solenoid 106. Solenoid 106 controls the flow of motive fluid in conduit 94 which in turn can effectuate rotation of the gear 89 in a clockwise direction in FIGURE 4. Rotation of gear 89 in a clockwise direction in FIGURE 4 results in an increase in the resistance of potentIometer 98 thereby increasing the time interval for energization of solenoid 116. Thus, it will be seen that energization of the switches 108 and 110 have opposite effects on the amount of powder discharged through funnel 34 into a receptacle such as a primer 6 cup 79 and compensate for the compressed powder height at the loading press consolidating station.

Solenoid 104 may be energized at any desirable time by manually closing switch 128. Likewise, solenoid 106 may be energized at any time by closing switch 134. Manual switches 128 and 134 may be energized at any time When it is desired to move the timer 148 to mid range should the compressed powder heights crowd too close to the limits of the predetermined range while still indicating acceptable production.

On tests conducted heretofore, consistency within two three milligrams was attained. Compensation can be controlled within two milligrams or closer by adjusting the limit stops 96 and 96'. When converting from loading of one type of powder to another, the only changes required are changes to the throat size in the hopper 32 or replacement of the entire hopper when loading explosives. Through experiments, it has been found that the diameter of the throat 33 should be .062 inch minimum for lead azide, 0.78 inch minimum for delay powder, and .102 inch minimum for RDX. The hopper 32 and shuttle 46 are preferably made from stainless steel type 304. All other components may be made of mild steel and chromeplated (.001.002 inch) except standard 68 which may be aluminum channel and plate. Other materials may be substituted as desired to suit the users need.

If desired, a manually operated switch 150 may be provided at a remote point. When it is desired to empty the loader of explosive powder, a receptacle may be placed below the funnel 34 and switch 150 activated to energize solenoid116. When all of the powder has been discharged from the hopper 32 into the receptacle, switch 150 will be opened. Whenever the loading apparatus is not in use, switch 124 should be in an open position. Also, the hopper 32 and related elements should be in the phantom position illustrated in FIGURE 3. The provision for means enabling the hopper to be rotated to the inoperative position shown in phantom in FIGURE 3 facilitates cleaning and removal of the hopper 32 and provides for easy access to the funnel 34. The U-shaped notch 35 enables the shuttle 46 to rotate to the phantom position in FIGURE 3.

While the above description is set forth in connection with an explosive powder, it is within the scope of the present invention to utilize the loading apparatus in connection with other types of powders and in other industries such as the pharmaceutical industry. While the description set forth above is described in connection with the use of powder in the hopper 32, obviously the apparatus may be utilized in conjunction with a liquid.

In case of an electrical power failure, the pneumatic motor 74 will continue to rotate wheel 52 thereby recirculating powder back into the hopper to avoid powder spillage. Each of the cylinders 40, 93 and 93 are oneway cylinders with spring return on their pistons so that the associated piston rods will be biased to an inactive position if there is a failure of the air pressure.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. Loading apparatus comprising a hopper, a shuttle means below said hopper, said shuttle means having a first position for enabling powder from said hopper to be discharged into a receiving receptacle, said shuttle means having a second position wherein said shuttle means directs powder discharged from said hopper to a recirculating means which returns such powder to the hopper, and means for selectively controlling the movement of said shuttle means between said first and second positions.

2. Apparatus in accordance with claim 1 wherein said last-mentioned means includes a motor means for moving said shuttle means to its first position and a spring for moving said shuttle means to its second position.

3. Apparatus in accordance with claim 1 wherein said recirculating means includes a device mounted for rotation through a closed loop, said device including pockets for receiving powder directed thereinto from said shuttle means, and said device being adapted to discharge any powder in the pockets into the hopper.

4. Apparatus in accordance with claim 1 wherein said last-mentioned means includes compensating structure for adjusting the time interval at which said shuttle means is in its first position as a function of the amount of powder compressed at a subsequent compacting station.

5. Apparatus in accordance with claim 1 wherein said last-mentioned means includes an adjustable potentiometer adapted to increase or decrease the time interval at which said shuttle means is disposed in its first position.

6. Loading apparatus comprising a hopper, said hopper having a discharge throat which is unobscured and through which matter may be continuously discharged, means below said throat for selectively diverting some of the matter discharged through said throat, and movable mechanical means for receiving such diverted matter and returning the same to said hopper.

7. Apparatus in accordance with claim 6 wherein said mechanical means includes a rotatable wheel within which a portion of said hopper is disposed.

8. Apparatus in accordance with claim 6 wherein said diverting means includes a reciprocable shuttle having a portion disposed within the confines of said mechanical means in one position of said shuttle.

9. Apparatus in accordance with claim 6 including a feedback compensating means for controlling the diverting of such matter whereby the amount of such matter discharged from said throat and not returned to said hopper may be controlled as to quantity by controlling the time period during which diversion of such matter is not being accomplished.

10. Loading apparatus comprising a housing, a hopper within said housing, a reciprocable shuttle below said hopper, said hopper having a discharge throat unobscured at all times, said shuttle having an aperture adapted to be aligned with said throat in one position of said shuttle, a wheel rotatably supported in a manner so that a portion of said shuttle and hopper are within the confines of said wheel, said wheel having pockets on its inner periphery to receive matter from said shuttle in another position of said shuttle, a funnel below said shuttle, and means for selectively moving said shuttle for controlling the time period during which said shuttle aperture is in line with said throat.

11. Apparatus in accordance with claim 10 wherein said last-mentioned means includes a compensating circuit for increasing or decreasing the time interval during which said shuttle aperture is in line with said throat.

12. In a method of loading a powder from a hopper into a receptacle comprising the steps of continuously discharging powder through a throat in said hopper, collecting powder from said throat in a receptacle, diverting powder from said throat, moving the receptacle, returning the diverted powder to said hopper, ceasing the diversion of powder, and collecting powder in another receptacle.

13. A method in accordance with claim 12 including controlling the time interval for said step of diverting powder in response to the amount of powder collected in said first receptacle.

14. A method in accordance with claim 12 wherein said step of returning the powder to the hopper includes collecting the diverted powder on the inner periphery of a rotating wheel, and dumping the so-collected powder back into the hopper by causing the hopper to be positioned within the inner periphery of said wheel.

15. A method in accordance with claim 12 including the step of controlling the period of time during which the powder is being collected in said other receptacle by varying the resistance of a potentiometer in a compensating circuit in response to the compressed height of powder collected in said first-mentioned receptacle.

References Cited by the Examiner UNITED STATES PATENTS 1,394,097 10/ 1921 Lachapelle 222318 X 3,087,517 4/1963 Magnuson et al. 141-1 3,107,703 10/1963 Smith 141-129 X LAVERNE D. GEIGER, Primary Examiner.

H. BELL, Examiner.

Claims (1)

12. IN A METHOD OF LOADING A POWDER FROM A HOPPER INTO A RECEPTACLE COMPRISING THE STEPS OF CONTINUOUSLY DISCHARGING POWDER THROUGH A THROAT IN SAID HOPPER, COLLECTING POWDER FROM SAID THROAT IN A RECEPTACLE, DIVERTING POWDER FROM SAID THROAT, MOVING THE RECEPTACLE, RETURNING THE DIVERTED POWDER TO SAID HOPPER, CEASING THE DIVERSION OF POWDER, AND COLLECTING POWDER IN ANOTHER RECEPTACLE.

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