US3020871A

US3020871A - Multiple barrel mine anchor-line cutter

Info

Publication number: US3020871A
Application number: US786736A
Authority: US
Inventors: Temple Robert; Joseph L Giebel; Ernest E Temple
Original assignee: Mine Safety Appliances Co
Current assignee: MSA Safety Inc
Priority date: 1959-01-14
Filing date: 1959-01-14
Publication date: 1962-02-13
Anticipated expiration: 1979-02-13
Also published as: FR1246465A; BE586492A

Description

Feb. 13, 1962 R. TEMPLE ETAL MULTIPLE BARREL MINE ANCHOR-LINE CUTTER 2 Sheets-Sheet 1 Filed Jan. 14. 1959 l ENTORS Efi/VEST TE/YPL 5 Their flttohhe/s Feb. 13, 1962 R. TEMPLE ETAL 3,020,871

MULTIPLE BARREL MINE ANCHOR-LINE CUTTER Filed Jan. 14, 1959 2 Sheets-Sheet 2 sweep line.

Sfifihfi'll Patented Feb. 13, 1962 This invention relates to cutting devices, by which the lines that anchor buoyant explosive mines under water can be severed, and more particularly to such cutters that are explosively actuated.

It is common practice to pull explosively actuated mine anchor-line cutters through the water by means of sweep lines attached to ships. In an attempt to reduce the number of individual cutters, several of them have been provided with the same stabilizing fin. Even with such an arrangement, the cutters create a considerable drag on It has recently been proposed to pull the sweep lines. the sweep lines through the water by helicopters flying just above the surface, but the drag offered by known cutters is still too great to make that feasible.

It is among the objects of this invention to provide a mine anchor-line cutter, which carries a plurality of cutting elements that operate in succession, which does not create turbulence in the water, which does not attempt to dive or rise, which is considerably lighter than the aggregate number of single barrel cutters required for carrying a like number of cutting elements, in which the stabilizing fin can be quickly attached and detached, and in which the firing mechanism is sealed from the surrounding water both before and after the cutter has been operated.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which I FIG. 1 is a plan view of our cutter mounted on a sweep FIG. 2 is a front view thereof;

FIG. 3 is a view of the cutter showing the front end of the frame;

FIG. 4 is a viewof the opposite end of the frame;

FIGS. 5 and 6 are enlarged fragmentary horizontal sections taken on the lines V-V and VIVI, respectively, of FIG. 2;

FIGS. 7 and 8 are fragmentary vertical sections taken on the lines VII-NH and VIIIVIII, respectively, of FIG. 5; and

FIG. 9 is a side view of one of the cartridges used in the cutter.

Referring to FIG. 1 of the drawings, a number of our mine anchor-line cutters are mounted on a sweep line 1 and towed through the water in the direction of the arrow by a mine sweeper or a helicopter. The sweep line is held at the desired angle and depth by means which form no part of this invention. Each cutter has two major parts; an elongated tool frame 2 and a tapered fin 3 that keeps the frame more or less horizontal and headed forward. To permit the cutter to be mounted on the sweep line, the frame isprovided with a central longitudinal slot 4 that opens rearwardly, as shown in FIGS. 3 to 8. The slot is just wide enough to accommodate the sweep line, which is held in it by the front end of the fin.

The fin includes a thin flat vane 6, the narrow front end of which is rigidly mounted in a metal bar 7. The bar has at one end a tongue 8 that extends into the front end portion of the frame slot and nearly engages the Opposite sides of the tongue are provided with ribs 9 that extend lengthwise of the frame a short distance and that are slidably mounted in grooves 10 formed in the opposite side walls of the slot. The ribs are inserted in the grooves by mov'mg the bar backwardalong the frame. The opposite or rear end of the bar is provided with an integral lug 11 of reduced thickness, which slides into a notch 12 in a tail-piece 13 fastened to the rear end of the frame by a central screw 14. The lug is held in the notch by a spring-pressed pin 15 mounted in one side of the tail-piece and projecting into a depression 16 in the side of the lug. The lug also is provided with a notch 17a extending from the depression to the rear end of the bar. Beside the open end of this notch the lug has inclined surfaces 17 that engage the pin 15 and depress it while the bar moves back, until the pin can snap out into depression 16. The bar also has a small tongue 18 that projects into the rear end of frame slot 4 and nearly engages the sweep line. To enclose the exposed rear edges of bar 7 and help hold the vane in place, curved members 19 fit over the opposite sides of the 'bar and engage the adjacent areas of the vane. The outer surfaces of these members curve forward from the vane to the upper and lower sides of the frame and form smooth surfaces for water to flow across. It will be seen that it is an easy matter to disconnect the cutter from the sweep line, by merely pushing the spring-pressed pin 15 back out of lug depression 16 by means of an instrument (not shown) inserted in a passage 20 in the opposite side of tail-piece 13. The head of the fin can then he slid toward the front end of the frame slot as lug notch 17a slides off the pin-depressing instrument. The tool frame then can be lifted off the sweep line.

Another feature of this invention is that the tool frame is provided with at least two cutting elements, most suitably in the form of cylindrical chisels. Preferably, there are two chisels 21 and 22 slidably mounted in parallel barrels 23 formed in the front side of the frame 2 at opposite sides of slot 4, about mid-way between the ends of the frame. As shown in FIGS. 5 and 6, the front of the frame at its rear end is cut away and the adjacent ends of the barrels are open. That is, the barrels open into mine anchor-line receiving recesses that are formed between the front of the frame and a couple of anvils 24 and 25 staggered lengthwise of the frame. The anvils have rear ends that fit in parallel slots 26 and 27 (FIGS. 2 and 4) in the rear end of the frame and tail-piece 13. Slot 26 extends lengthwise of the frame farther than the other so that anvil 24 will be located closer to chisel 21 than the other anvil is located relative to chisel 22. The anvils are held in the slots by shear screws 28. Each anvil extends forward perpendicularly to the frame and then laterally a short distance toward the opposite end of the frame and then forward again at an oblique angle. When the frame engages the first mine anchor-line 29 (FIG. 1) the frame will slide across the line, which will be directed by the front end of the forward anvil 24 into the recess that the anvil and frame form in line with chisel 21.

To drive the chisels out of the barrels, an explosive cartridge 31 is disposed in each barrel. As shown in FIG. 5, each cartridge has a base portion with a thick side wall located directly behind the chisel and substantially filling the inner end of the barrel. The rest of the cartridge has a thin side wall that extends forward into an axial bore 32 in the inner or rear end of the chisel. This telescoping of chisel and cartridge permits the length and weight of the frame to be reduced. When such a cartridge is fired, its side wall is ruptured where the thin wall joins its heavy wall. This allows the expanding gases to engage the rear end of the chisel around its central bore and thereby the gases act upon a greater area of the chisel than just the inner end of the bore. Of course, the thin wall portion of the cartridge leaves the cutter with the chisel. The force of the explosion also expands the base portion of the cartridge, which feinains in thefratne after firing, so thatthe baseportion will not be thrown out of the barrel when the second cartridge is fired, which would allow water and mud and the like to foul the first firing pin,

The base portion of each cartridge is threaded so that a threaded rod (not shown) can be inserted in the barrel and screwed into the cartridge base in order to pull it out of the barrel to permit the tool to be reloaded. The base portion of each cartridge also is provided with aperipheral groove, in which is mounted asealing ring 33 that com-pressed against the side of the barrel to prevent water from seeping past the cartridge. 'It is likewise preferred to mount an additional sealing ring 34 in a groove around the chisel to keep water from even reaching the cartridge before it is fired.

' In order to tire the cartridges, a firing pin 36 is slidably mounted in a small hole in the frame directly behind each cartridge. Each pin issupported by a cylindrical slide 37, preferably integral with it, that is movable-back and forth in a bore 38 in the frame; The pin is urged away from the cartridge by a coil spring 39 compressed between a shoulder on the slide and the front end of the bore. The

rear end of the bore is closed by a plug 40 that is encircled by an O-ring 41 which seals that end of the bore. Extending out of one side of the rear end of the bore, preferably atright angles to it, is a passage 42, which has an outer end portion that extends back through the frame toward the anvils. The outer end of the passage opens into a small slot 43 in the frame, which is open to the surrounding weer. r slidably mounted in the portion of passage 42 that is perpendicular to bore 38, is a piston 45 provided with a circumferential groove in which a sealing ring 46 is compressed to prevent water from passing the piston and getting into the slide bore. The adjoining ends of the piston and firingpin slide engage each other alongsurfaces in clined to their axes, so that if the piston is pushed farther into the bore, it will pushthe firing pin toward the cartridge. The meeting ends of the piston and slide are held together by a hook and pin. Preferably the pin 47 is mounted across a slot 48 (FIG; 7) extending diagonally across the piston, and the hook 49 projects from the inner 'end of the slide into the slot and part way around the pin. .If the tool is dropped, this pin and hook connection will prevent the jar from accidentally forcing the firing pin against the cartridge. The connection also prevents the recoil due to firing of one cartridge from causing the other firing pin slide to move toward the other cartridge and fire it.

When it is time to fire a cartridge, the water in a passage 4-2 is suddenly put under sufficient pressure to drive the piston therein forward against the adjoining slide 37, which is thereby forced toward the cartridge. The water pressure is created by a plunger Stl slidably mounted in a recess in the back side of the frame. The exposed side of each recess can be closed by a cover plate 51. Each plunger normally is held in a retracted position, with its front end behind the water inlet slot 43, by means of a headed trigger pin 52 extending through a hole in the frame as shown in FIG. 5. The inner end of the pin projects into a hole 53 in the plunger near its rear end, and the outer portion of the pin extends across the cutting recess and through the adjoining anvil. When the inner end of the trigger pin is withdrawn from the plunger, the latter is shot forward by a coil spring 54 compressed between a shoulder 55 on the plunger and a washer 56 slidably mounted on the plunger and bearing against the frame. A shear pin 57 in the chisel compels the explosion to build up considerable pressure before that pin is sheared off and the chisel 21 shot out of the barrel with great force. In fact, the force is great enough to cut the anchor-line and break the shear pin 28 by which the anvil 24 is held in place, so that the anvil will separate from .the frame and not catch. on the next mine anchor-line.

The latter is thus free to be caught by anvil 25 and to fire the other cartridge so that chisel 22 will cut the line. The rear ends of plungers 50 are threaded so that they can be gripped by a threaded socket member (not shown) and pulled back to cock the tool after new anvils and trigger pins have been installed.

It will be seen that a single, light Weight frame carries two chisels, so that the cutterwill create considerably less drag on a sweep line than would two ordinary single barrel cutters. Another big advantage is that the sealing rings keep all water awayfrom the firing mechanism. That is highly desirable because water would interfere with the action at the firing pins. Also where water can enter, silt, sand and mud can enter likewise, and that means that the firing mechanism would have to be dismantled and cleaned after every use of the cutter. Our invention makessuch cleaning unnecessary.

The stabilizing fin can be quickly snapped into place in v cutter therefore can be pulled through the water at a speed of between twenty and thirty knots by a helicopter.

The location of thesweep line in the tool frame. near its front side, and the tapered front end of the frames assures that a mine anchor-line will pass smoothly from the sweep line along the frame to the cutting recess without jumping over the anvils.

According to the provisions of thepatent statutes, we have explained theprinciple of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of theappended claims, the invention may be practiced otherwisethan as specifically illustrated and described.

We claim:

1. A mine anchor-line cutter comprising a frame, a longitudinally movable cutting element in the frame, means connected to the frame adjacent the cutting end of said element for receiving an anchor-line in position for cutting, a cartridge in the frame at the opposite end of said element, a sealing ring encircling the cartridge to keep water from passing it, the frame being provided behind the cartridge with a bore, a firing pin in the bore, a slide in the bore behind the pin for moving it forward, the frame being provided with a passage open at one end and having its opposite end opening into the rear end of said bore at an angle thereto, a piston in said passage engaging the rear end of said slide, the engaging ends of said piston and slide being inclined to the axes of the piston and slide, a sealing ring encircling the piston in sealing engagement therewith and with the wall of said passage, and spring-actuated means carried by the frame for forcing water into said open end of the passage to cause the piston to move the slide forward.

2. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, means connected to the frame adjacent the cutting ends of said elements for receiving anchor-lines in position for cutting, the frame being formed to support explosive means adjacent the opposite end of said elements for driving them toward said linereceiving means, said frame being provided with a central longitudinal slot for receiving a sweep line, said slot opening to the rear of the frame, and a stabilizing fin attached to the frame and having its front end closing the open side of the slot to retain a sweep line therein.

3. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, means connected to the frame adjacent the cutting ends of said elements for receiving anchor-lines in position for cutting, the frame being formed to support explosive means adjacent the opposite end of said elements for driving them toward said linereceiving means, said frame being provided with a central longitudinal slot for receiving a sweep line, said slot opening to the rear of the frame, and a stabilizing fin having its front end mounted in said slot and formed to hold a sweep line against the front Wall of the slot.

4. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, means connected to the frame adjacent the cutting ends of said elements for receiving anchor-lines in position for cutting, the frame being formed to support explosive means adjacent the opposite end of said elements for driving them toward said linereceiving means, said frame being provided with a central longitudinal slot for receiving a sweep line, said slot opening to the rear of the frame, a stabilizing fin having its front end extending into said slot, the slot and fin being provided at one end of the frame with interengaging ribs and grooves extending lengthwise of the frame, and means at the opposite end of the frame detachably connecting the fin and frame together.

5. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, an anvil spaced from the cutting end of each cutting element and forming with the frame a recess for receiving a mine anchor-line, a shear pin connecting each anvil to the frame, the anvils ,being spaced different distances from the adjacent cutting elements, the frame being formed adjacent the opposite end of said elements with explosive means receiving chambers, and means in said recesses engageable by mine anchor-lines in succession for firing explosive means in said chambers in succession to drive the cutting elements against the anvils with suificient force to shear said pins.

6. A mine anchor-line cutter comprising a longitudinally movable cutting element, means adjacent the cutting end of said element for receiving an anchor-line in position for cutting, means adjacent the opposite end of said element to receive an explosive charge, a firing pin for exploding the charge to actuate the cutting element, a slide behind the pin for moving it ahead, a piston disposed at an angle to the rear end of the slide, the slide and piston having inclined engaging end surfaces, the adjoining ends of said slide and piston being provided with an interengaging hook and cross pin for holding them together, and spring-actuated means for forcing 6 water against the piston to cause it to push said slide ahead.

7. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, means connected to the frame adjacent the cutting ends of said elements for receiving anchor-lines in position for cutting, the frame being formed to support explosive means adjacent the opposite end of said elements for driving them toward said line-receiving means, said frame being provided with a central longitudinal slot for receiving a sweep line, said slot opening to the rear of the frame, a stabilizing fin having its front end extending into said slot, the slot and fin being provided at one end of the frame with interengaging ribs and grooves extending lengthwise of the frame, the fin at the opposite end of the frame being provided with a lateral recess, and a spring pressed pin mounted in the frame beside said recess and projecting into it to detachably lock the fin and frame together.

8. A mine anchor-line cutter comprising a frame, a pair of laterally spaced parallel cutting elements slidably mounted in the frame, an anvil spaced from the cutting end of each cutting element and forming With the frame a recess for receiving a mine anchor-line, a shear pin connecting each anvil to the frame, one of the anvils being located closer than the other to the adjacent end of said frame, the frame being formed adjacent the ends of said elements opposite their cutting ends with explosive means receiving chambers, and means in said recesses engageable by anchor-lines in succession for firing explosive means in said chambers in succession to drive the cutting elements against the anvils with sufficient force to shear said pins.

References Cited in the file of this patent UNITED STATES PATENTS 662,137 Tellerson Nov. 20, 1900 2,135,888 Febrey Nov. 8, 1938 2,216,359 Spencer Oct. 1, 1940 2,262,925 Cole Nov. 18, 1941 2,422,506 Temple June 17, 1947 2,601,245 Bowersett June 24, 1947 2,667,837 Musser Feb. 2, 1954 2,759,419 Hitchens Aug. 21, 1956 2,800,868 Temple July 30, 1957 2,806,442 Temple Sept. 17, 1957 2,910,034 Sullivan Oct. 27, 1959 2,953,092 Walker Sept. 20, 1960