US2515323A - Tamping machine - Google Patents

Description

July 18, E950 J. sTuARTJI TAMPING MACHINE Filed Jan. 23, 1947 3 Sheets-Sheet l JOSEPH STUART 1: Fl G I INVENTOR.

BY WQF AGENT In v um C mm G TN Sn im Jufly 18, 1959 3 Sheets-Sheet 2 Filed Jan. 23, 1947 JOSEPH STUART 11 INVENTOR.

My P

AGENT J. STUART, II

TAMPING MACHINE July 18, 1950 3 Sheets-Sheet 3 Filed Jan. 23, 1947 JOSEPH STUART 11 FIG.5

INVENTQR.

AGENT Patented July 18, 1950 TAMPING MACHINE Joseph Stuart, II, Wilmington, DeL, assignor to Hercules Powder Company, Wilmington, DcL, a corporation of Delaware Application January 23, 1947, Serial No. 723,833

8 Claims.

This invention relates to an improved tamping machine, and more particularly, to a reciprocating hydraulic tamping machine for filling and packing cartridges with dynamite or other explosive materials.

In the packaging of dynamite, particularly in the packaging or filling of large diameter cartridges with dynamite, difiiculty has heretofore been encountered in obtaining a, uniformly packed product of a density readily controllable over awide range. It is desirable that successive dynamite cartridges be of uniform density in order that the explosive effect of these cartridges may be depended upon to be consistent.

The object of this invention is to provide a machine by which cartridges can be uniformly packed with explosive materials.

A further object of this invention is to provide a machine to automatically fill cartridges with an explosive material by a, hydraulically actuated tamping means.

A further object of this invention is to provide a machine which will provide a uniform application of pressure to the explosive material being packed in cartridges.

A further object of this invention is to provide a machine which will produce a cartridge filled with an explosive packed to a depth and density readily controllable at the discretion of the operator.

Other objects of the invention'will appear hereinafter, the novel features and combinations being set forth in the appended claims.

Generally described, this invention includes a tamping device hydraulically actuated, controls for the actuation of the tamping device, a storage member for an explosive material in alignment with the tamping device, a cartridge support assembly, and controls for the actuation of the support assembly.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification, wherein Figure l is a partially broken front elevation of the machine; Figure 2 is an enlarged front elevational view in partial section of the adjustment control shown in Figure 1; Figure 3 is an enlarged partial section of the tamping cylinder assembly taken along line 3-3 of Figure 1; Figure 4 is a schematic diagram illustrating the hydraulic and electric systems for. operating and controlling the invention. Figure 5 is a partially broken front elevation of an alternative embodimerit of the invention.

With reference to Figure 1, I0 is the frame of the machine, the cross members of which support the tamping cylinder assembly H and the funnel [2. The tamping rod i3, preferably made of hard wood and secured to the piston rod M by suitable securing means, is reciprocated vertically by a pressured oil supply to the tamping cylinder assembly I I through the upward pressure connection 15, tending to give upward movement to the piston rod l4 and the controlled oil pressure through the adjustable pressure connection It tending to give a downward movement to the piston rod M when the opposing force applied through the opposite pressure connection is removed.

The piston rod I l is enlarged at its upper end forming a, control block H to provide a means of actuating the plunger roller l8 and plunger IQ of control valve 20. Control valve 20, the vertical location of which determines the height to which the explosive material is packed in a cartridge 2|, is positioned vertically by adjustment means such as provided by the jack 22. The function of the control valve 20 is further described with reference to the hydraulic and electric systoms of Figure 4 in a subsequent paragraph. Resilient pads 23 are located on the frame it! and tamping cylinder assembly I l to absorb the shock upon being struck by the control block I? at the extremes of its travel.

The cartridge 2! to be filled by explosive material is fitted over the outlet of a storage means such as funnel I2 containing the explosive material and held in place by a, support means such as a support block 24 which is in turn raised into position by the air cylinder piston rod 25 of air cylinder 26. The movement of the air cylinder piston rod 25 is regulated by the control of air to the inlet and outlet connections 21 by means of a four-way valve 28 shown in Figure 4. The funnel I2 is supported by a cross member of frame EU, said cross member being in hinged attachment to frame it to facilitate removal of funnel 62 when necessary to be substituted by one whose outlet is of a size to accommodate another cartridge size. V

With reference to Figure 2, a preferable vertical adjustment means of control valve 20 is shown in partial section. The turning of adjustment wheel 29 with its threaded shaft 30 extending in threaded attachment to lift pin 3| will raise or lower control valve 20, through the connecting linkage composed of rod 32 and bracket guide 33.

as Guide sleeve 35, attached to guide plate 35, is

suitably attached to lift pin 3|. As the turning of adjustment wheel 29 vertically actuates the control valve 20, guide sleeve 34, along with the attached guide plate 35 in guided slidable relationship to the rods 36, acts as a support and as a stop at the limits of travel of lift pin 3|. The valve bracket 31 is secured in fixed relationship to bracket guide 33, slidably retained by guide block 38 and guide block cover 39. Control valve 26, of a suitable design known to the art, is attached to valve bracket 31 in such a position as to place the plunger roller I9 of plunger I9 in the path of travel of control block I 1 shown in Figure 1. When in contact with the reciprocating control block I1, the plunger roller I8 actuates the attached plunger I9 into the control valve body to a position to prevent ingress of air by way of control valve inlet connection 46 and egress of air from control valve outlet connection 4|. When not in contact with control block I1, the plunger roller I8 and plunger I9 are on the extreme outward position to permit both ingress and egress of air in control valve 20. A more complete description of the function of the control valve in the regulatory system of this invention will be subsequently disclosed.

With reference to Figure 3, the tamping cylinder assembly I I is composed of piston 42 with cup packing 43 held in clamped attachment thereto by clamping means provided by packing retainers 44 held in the position shown by threaded relationship with retainer stud 45. Piston rod I4, rigidly secured by suitable means to the packing retainers 44, extends from both sides of piston 42 and being of smaller diameter than the inside diameter of cylinder 46, an upper fluid pressure chamber 41 and a lower fluid pressure chamber 46 are formed on the upper and lower side respectively of the piston 42. Cylinder heads 49 are attached to both ends of cylinder 46 with ad- Justably attached packing gland nut 56 holding packing I tightly in a cavity formed between cylinder' head 49 and piston rod I4 in order to effectively prevent the escape of fluid from chambers 48 and 41.

Figure 4 is a schematic diagram showing the hydraulic system for operating the upward and downward strokes of the tamp rod, the air system for operating the air cylinder, and the electrical control system for securing automatic or manual operation of the invention.

In the example illustrated the source of power is an electric motor 52, supplied with electrical energy from a current source 53 through starter box 64. The starter box 54 in turn is controlled 'by a time relay 55 actuated by the time pressure switch 56 or by manual operation of the pushbutton station 51. The time pressure switch 56 is intermittently supplied with a charge of air under pressure by the cam operated valve 58 which is actuated by a lobe on cam 59. The valve 58 is supplied with air under pressure through intake 60.

The cam 59 is turned by an extension of the pump shaft 6| and positioned so that a charge of air will be supplied to time pressure switch 56 when the end of the downward stroke of tamp rod I3 has been reached by a lobe of cam 59 actuating a plunger of valve 58 inwardly to a posi-' tion to allow air from intake 66 to be admitted to time pressure switch 56. With the plunger roller I8 and plunger I9 of control valve 20 in an inward position when in contact with control block I1 and preventing the egress of air from control valve outlet connection 4|, the pressure is maintained in the time pressure switch 56. If the plunger I9 is allowed to maintain this position for a longer interval than that for which the time pressure switch 56 is set, the time pressure switch will actuate the time relay 55 at the moment permitted by entry of pressured air from valve 58, in turn activating the starter box 54 to stop the motor 52. This will stop the pumping action of reciprocating pump 62, thus no reciprocating fluid pressure will be supplied to the tamping cylinder assembly I I through adjustable pressure connection I6, by downward pressure cylinder 63 of pump 62 or to the upward pressure connection I5 by an upward pressure cylinder 64 and the end of the tamp rod l3 will be locked in a position within the neck of the funnel I2 when the cartridge 2| is full. In the cycle of operations, pressure supplied by the downward pressure cylinder 63 will force the piston 42 downward and at the same time aid in forcing the return of fluid through the upward pressure connection I5 to the upward pressure cylinder 64 and vice versa.

The pushbutton station 51 connected to the starter box 54 is used at the discretion of the operator to stop or start the movement of the tamping rod I3. Movement of the tamping rod I3 can be made "automatic as subsequently described or manual which involves the operator's manipulation of the pushbutton station 51 .by the proper setting of the automatic-manual selector station 65. The manual setting is used when the operator desires to raise the tamp rod to its uppermost position after the tamp rod has been automatically stopped with the end of the tamp rod II within the neck of the funnel I2.

The pressure cylinders 63 and 64 of the reciprocating pump 62 each displace in one stroke of piston 66 or 61 of said respective cylinders the volume of fluid necessary to actuate the tamping rod in a given direction to its extreme position. As the cartridge 2| becomes filled with dynamite from the funnel I2 the downward stroke of the tamp rod necessarily becomes shorter and the excess fluid pumped is relieved through pressure relief valve 68 set at a desirable relieving pressure commensurate with the density of pack required. The by-passed fluid from the pressure relief valve 68 flows into a fluid tank 69.

The upward stroke of the tamp rod is performed by fluid forced into the tamping cylinder assembly by the piston 61 and the excess fluid pumped is relieved through pressure relief valve 16. The by-passed fluid from the pressure relief valve lllflows into the fluid tank 69. It should be noted that in the preferred pumping arrangement shown, the pistons 66 and 61 are connected to a common arm of crank shaft 6| whereby on an outward pressure exhaust stroke of piston 66 an opposite intake stroke of piston 61 takes place and vice versa. A supply line to each pressure cylinder from the tank 69, with a suitable loaded check valve 1| therein to prevent discharge back into the tank on a compression stroke, serves to supply makeup fluid to the system to replenish that which may be lost.

The air supply 12 is connected to the four-way valve 28 which is manually controlled at the discretion of the operator to provide either upward or downward movement to the air cylinder piston rod 25 by way of inlet and outlet connections 21 of air cylinder 26.

The automatic operation of the invention is as follows, referring to Figure 4: the funnel I2 is kept su plied with explosive material to be tamped or packed into the cartridge ii. The selector station 65 should be set for automatic operation. By pressing the "start" button of pushbutton station the tamping rod I3 is given the desired vertical reciprocating motion and pushes before it explosive material from the funnel l2 into the cartridge 2|. With each stroke of the tamping rod is the level of the packed explosive material in cartridge 2| rises and it is evident that as the strokes become shorter a longer pause will take place at the end of each stroke during which interval the excess fluid pumped by the cylinders 63 and 643 will be discharged through the respective relief valves 88 and into tank 69.

At the discretion of the operator a loosely or tightly packed cartridge can be produced merely varying the pressure at which the relief valve 68 is set to relieve the actuating pressure to adjustable pressure connection it.

When the cartridge ii is filled to the desired depth and the 'control valve 20 located in the proper position in the vertical path of control block H, to maintain the plunger roller l8 and plunger IS in contact with the control block ii at the end of its downward stroke and in an inward pressure holding position for a sufilcient interval to actuate the time pressure switch 88, the time relay 55 and starter box 56 are actuated to stop the electric motor 52 and reciprocating pump 62 supplying the tamping actuating medium. Termination of the tamping operation is thus accomplished with the end of thetamp rod within the neck of the funnel ii. The control valve 26 is raised or lowered to the desired location by manipulation of adjustment wheel 29. The time during which pressure must be maintained before the circuit is closed in the time pressure switch 55 is adjustable and details of construction and operation of a switch of this type is well known to those versed in the art.

With the cartridge 2i filled to the desired depth and the tamp rod automatically held inoperative by the termination of movement of the fluid in the system, the operator may turn the control handle of the four-way valve 28 to direct the air supply to cylinder 28 so that the air cylinder piston rod 25 will be forced downward carrying with it the support block 2%. The loaded cartridge it may be taken out of the machine and an empty cartridge 26 placed on the support block 26 ready to be raised into position under the funnel by manipulation of the four-way valve 28. In order to start the tamping operation the start" button or pushbutton station 577 is pressed and the operation described above is repeated.

If manual operation is desired the automaticmanual switch 65 is set at manual and the tamping operation can then be started or stopped at the will of the operator by using the pushbutton station 5?.

.In the alternative embodiment of the invention shown in Figure 5, the frame it has been elongated to receive a plurality of vertically dis= posed and horizontally spaced tamping cylinder assemblies ll, funnels 62, air cylinders 26, related control mechanism and so forth described hereinabove with reference to the preferred embodiment.

The elongated valve bracket 58 extends across the front of the invention and is supported at each end by a bracket guide 83 oi the adjustment control shown in and described with reference to Figures 1 and 2 oi the preferred embodiment of the invention. A control valve 2a is attached to ity. An outstanding feature of this device is the.

high degree of safety with which it can be operated and controlled over a wide range of tamping pressures imposed upon the dynamite in thetamping operation.

What I claim and desire to protect by Letters Patent is:

1. In a machine for tamping dynamite into cartridges, the combination with a frame of a tamping means including a, tamp rod and a doubleacting hydraulic cylinder assembly; means for hydraulically actuating said tamping means including a hydraulic fluid reservoir, a hydraulic fluid pump connected by supply lines to said cylinder assembly with opposed cylinders having pistons therein connected to a common crank arm operable to alternately supply fluid to and exhaust fluid from each end of said cylinder assembly, adjustable relief valves adapted to relieve the pressure in said supply lines into said reservoir at a predetermined pressure, a'makeup supply from said reservoir to each pump cylinder. and a rotative motive power for said pump; control means for said hydraulic actuating means; a storage member for said dynamite in coaxial alignment with said tamp rod and adapted to retain the material to be tamped; a cartridge support assembly; and means of supply and control of a pressured fluid to said support assembly.

2. In a machine for tamping dynamite into cartridges, the combination with a frame of a tamping means including a tamp rod and a double-acting hydraulic cylinder assembly; means for hydraulically actuating said'tamplng means; control means for said hydraulic actuating means including a control valve disposed in the path of and responsive to contact with said tamping means, vertical adjustment means for said control valve, and means responsive to said control valve adapted to stop the tamping of said cartridge when a predetermined level has been reached in filling said cartridge; a storage member for said dynamite in coaxial alignment with said tamp rod and adapted to retain the material to be tamped; a reciprocable cartridge support assembly; and means of supply and control of a pressured fluid to said support assembly.

8. In a machine .for tamping dynamite into cartridges, the combination with a frame of a tamping means including a tamp rod and doubleacting hydraulic cylinder assembly; means for hydraulically actuating said tamping means; control means for. said hydraulic actuating means including a control valve disposed in the path of and responsive to contact with said tamping means, vertical adjustment means for said control valve, a means responsive to said control valve adapted to stop the tamping of said cartridge when a predetermined level has been reached in filling said cartridge; 2. storage member for said dynamite in coaxial alignment with said tamp rod having an outlet adapted to retain one end of said cartridge in coaxial alignment with said tamp rod; a cartridge support assembly; and

' is mechanically actuated thereby; a stationary storage means for dynamite for the tamping assembly disposed in coaxial alinement with the tamp rod and having an orifice in the bottom thereof through which the tamp rod and dynamite may pass; and a cartridge support assembly.

5. A machine for tamping dynamite into cartridges having in combination a support frame; at least one tamping assembly including a reciprocable tamp rod and a double-acting hydraulic cylinder assembly; means for supplying pressurized hydraulic fluid to the tamping assembly; means for controlling the flow of the pressurized hydraulic fluid which include a control valve assembly disposed in the path of a reciprocable portion of the tamping assembly and which is mechanically actuated thereby; a stationary storage means for dynamite for the tamping assembly disposed in coaxial alinement with the tamp rod and having an orifice in the bottom thereof through which the tamp rod and dynamite may pass; a reciprocable cartridge support assembly; and means of supply and control of a pressurized fluid to said support assembly.

6. A machine in accordance with claim in which the tamping assembly comprises a doubleacting hydraulic cylinder, a piston disposed therein, a piston rod extending from upper and lower surfaces of the piston, and a tamp rod secured to the lower end of the piston rod.

'7. A machine in accordance with claim 5 in which the means for supplying pressurized hydraulic fluid to the tamping assembly comprises a reservoir for hydraulic fluid; a pump for hydraulic fluid connected by supply lines to the opposite ends of the tamping assembly cylinder, said pump having opposed cylinders, each 01 which containsa piston connected to a common crank arm and being operable to alternately supply hydraulic fluid to and exhaust hydraulic fluid from each end of the tamping assembly cylinder; adjustable relief valves disposed in each of said supply lines and in communication with the reservoir; a make-up supply from said reservoir to each pump cylinder; and rotative power means for said pump.

8. A machine in accordance with claim 5 in which the control means has in combination a valve assembly mounted in a vertically adjustable position adjacent the tamping assembly and comprises a body equipped with a passageway for fluid medium; a chamber disposed in the body which intersects the passageway; a plunger, one end of which is slidably disposed in the chamber and restrained by resilient means for closing the passageway; and a roller mounted on the end of the plunger and disposed in the path of a reciprocable portion of the tamping assembly; one end of said passageway being connected to a source of pressurized fluid medium and the other end being in communication with a time-pressure switch which interrupts the flow of hydraulic fluid to the tamping assembly when the reciprocable tamping assembly member contacting the roller causes the plunger to interrupt the flow of fluid medium to said switch for a predetermined period of time.

JOSEPH STUART, II.

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

UNITED STATES PATENTS Certificate of Correction Patent No. 2,515,323

July 18, 1950 JOSEPH STUART, II

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 5, line 28, for switch 86 word for read from;

and that the said Letters Patent should be rea may conform to the record of the case 1n the read switch 56; column 8, line 20, for the d as corrected above, so that the same Patent Ofiice. Signed and sealed this 17th day of October, A. D. 1950.

THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents.

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