US2396731A - Cable cutter - Google Patents

Description

-March 19, 1946. B, A. WIENER 2,396,731

CABLE CUTTER Filed Oct. 1, 1942 INVENTOR.

BERNARD A. WIENER WMMVQ 111s ATTORNEY Patented Mar. 19, 1946 UNITED STATES I PATENT OFFICE.

CABLE CUTTER." Bernard A. :Wiener, Washington,aI). C.

, Application octob'erl; 1942, Serial' No'. 460;425

:9 Claims;

(Granted under the act of 'March 3, 1883,=as'

amended-5116130, 1928; 370 0. G. 757) Thishinventionisnin. cable cutters, particularly such cutters-as are carried .by mine sweepers.

The usual procedure in sweeping minesisto dragor tow acable equipped with cuttingdevices through .the water, more or less horizontally,;at such depth that the towed cable. will intercept the. cables by which explosive mines are commonly anchored below the water'surface. The towed cable may be stretched betweentwo.towing craft, or one end thereof may becarried by a paravane or water kite. When .the towed cable and a mine mooring cable engage, the latter slides along the sweep cableuntila cutting device isreached. There the mooring, cable .istcut, and the freed mine bobs-to, thesurface offthe water, where it is destroyed or otherwise disposedof.

Cable cutters most frequently usedare mere V-shaped elements, the inside: surfaces-of which are sharpened. The mooring. cable entersthev,

which is'relatively narrow, andis 'carriedback to the :point, where it isengaged by the aforementioned sharpened surfaces, and: severed:

Attempts have been made to improve mine. cablecutters. In, general, the improvements take one of four forms. (1) The'device includesexplosive means for driving the cutters closedon a cable to cut the same.- driven closed vby sweep wire tension. cutter includes a power driven rotating 1 saw or. knife for severing. the cable. tains ,jaws with knives which are mechanically closed. on the mine mooring: cable because of con-- tact between the cutter and 'theaica'ble and the drag of the latter.

The explosive-type cutter is not-entirely satisfactory for at leasttwo reasons: itlisdifiicult to waterproofthe charges sufficiently-to makeoperation certain; 'and, unless the par-tssare made very. nicely (which resultsinan expensive: structure) ,they themselvesare aptto'be damaged by;

the explosion of i a charge.

Thosecutters so far developed to utilize in-' crease in sweepwire tension in l the cutting Y operation have been very 'heavyand cumbersome;

.Therotating-type cutter must contain a motor,

and electric leads or some other power-supplying means Not only arethere insulation problems,

but: devices of 'this nature are apt to belarge and.

unwieldy.

Cutters of the fourth type mentioned above- (of which my invention 'is an example)" can be relatively light andrelativel'y" simple. They 'donotordinarily develop the power off the devices of'ithe first'mentione'd three types, but they em-- (2) The knives are: (3) The,

(4). The cutter convide-a simple cable-cutter wherein thetinertia. and dragforcesof the mine-case. and mines-an-v choraneedv not be large for the cutter to sever successfully the, mine mooring cable.

An additional object of the invention is to providea cable cutter with a movable-cutting element, wherein a greater. mechanical .advantage is achieved as :the cutting-operationprogresses andbecomeszmore diflicult.

Other objects willappear from the followin specification and claims.

In the drawing:

Figure. 1 is aperspective View of the-cable -cut-- ter, with-portions of therstructure broken away;

ofFigure 1, butwith.theknivesclosed on a cable; Figure 3 is a section taken on-theline 3-3 of Figure.2;i

Figure lis a section throughthe .cuttingknives-r an arm H mounted on the body-member lll between ear-like appendages l and ID" by means. of a ..pintle bolt l 2 for movement Jrelative to the body member, and-aispring l 3, one end ofiwhich:

is "securedfto. the; body member l0 by meanszof theiscrew- Mand the .otherend ofwhich is at-'- tached to the-:arm ill byimeansof the screw J5,-

the spring; l3 thereby serving, to maintain the arm Iii-normally? in the-position shown in.E'ig.-.-

ure 1. and to'return it to :such position aftera cutting-operation.

tion with a knife I6.

be integral with the body member, butpreferably, 40

beenfound desirable-not to have-the cutting :.ele;- ment'ifitrthe slot completely at all points, but. instead to have the corners cutoff "somewhat, as

at l8 and. i9. This kind-of construction makes:

somewhatisimpler the removal of a: cutting ele-- ment, when such 'removalis desirableor neces. sary. The hole 22,.whichpassesentirelythroughthewbody member, also aids, in the-removalof -the knife. Should'the cutting. element become.

stuck-in thebody memberbecause of rustior corrosion; or for any other reason, it can. be forcedi outv by; inserting: in the hole 22 a. suitable tool, as. an ordinary rod, and exerting downwardqpressure on the'element. Thepknife lt-isnormally secured'inplace in, the body member by means of the'screws 20 and-2|.

'Itmaybe saidhere that in this description-the expressionsffupper, lower? etc, unlesswother ctr-wise noted, have referenceto.theadrawingaonly;

Figure. 2 is a detail of --a; portion of the 1 cutterj trate'dycomprises essentially a body member in,

is aseparateelement (aszshown) which fits; into aslotprovidedrfor it. In the:v latter; case, it has;

and do not define the locations of parts while the cutter is in operation.

The movable tgarm; lis provided gin-it's "upper portion with a "cutting element 233 This knife may be formed integral with the arm I I if desired,

Figures 3 and 4), and screwed in place by means vided which serves not only to space the arms 3| and 32 properly butto give this portion of the cutter.

The knife 23 has formed thereon an extension 29. The front portion thereof should conform to the shape of the filler block 33. The upper -por tion 29 forms an incline leading to the edge of knife 23. The function'of the portion 29 will be described hereinafter.

A fin is provided at the lower end of the cutter. This may be of any desired construction, but as shown consists of two'plates 36' and 31 (see Figures 1 and 5) Plate 36is welded or otherwise seneeded strength to cured to the appendage Hi, and plate 31, toappendage Ill". The plates are substantially parallel at their upper portions, and then are bent toward each other, at 36 and 31', so that their lower portions may be joined,-as at 38. The parallelarrangement' above the points 36', 31', leaves space betweenthe plates for the operati'on'of the movable arm H and the spring 13. 7 If the cable cutter is to be towed at'high speeds, no fin is necessary, sincethearea of the cutter proper is suflicient to cause it to assume its proper position in the water;- Whenthe operation is to becarried out at low speeds'g 'however, the dee scribed fin, or its equivalent, should be used.

The body member is provided with means' for attaching the cablesby which'the cutter is'towed,

as'the holes 4! and 42. "Oneend of a cable is attached directly or indirectly'to the towing ship. Theother end is secured, usually by means of a swivel, through the hole 4|. 'A'second cable is secured, also with a swivel, in the hole 42; and its other end is carried by a paravane or the like.

Ju'st above the opening between the'cutting surfaces is provided a 'member'43which may be termed a bumper bar. This bar is not essentialto the successful operation of the cutter so long ascables only are encounteredL'- Ithas animportant function, however,when,-a's frequently" happens, a mine ismoored withachain instead of a cable. For the cutter to operate successfully on chain, it is essential that the chainlink to b cut enter flat between the knives; if-itishouldenter upright, it might *jam the cutter, andcompletely prevent operation. The bumper bar 43 acts to turn 'overany upstanding link of chain, and insure that it lie flat between theknives;

The operation of the cutter is as' follows: with of the screws 24 and 25. The front portion of knife 23 coincides with the front of the arm I i the rear portion, as at 26, is cut off to provide i a meansanalogous to the hole 22--for removing '2 ii, Pu 1 9. 1?

the sweep cable. attached as described, the cutter assumes a" position the water'such'fthat the cu tter between the fixed knife IS in the head portion' of the body l0 and the knife 23 on the movtrailing fin is substantially horizontal. When that portion of the sweep cable between the ship and the attachment'orifice 4lfintercepts a mine moorin'g'cable, the latter slides along the former until the mooring cable enters the opening in the cable but is shown as detachable. It is notched to fit a notched section at the top of the arm l;l (see;

ablejjmember ll. After entering the opening, the

mooring cable strikes the lugs 21 and 28 of the movable member H and forces the lugs and the 'niovable member with its sharpened surface rearwardly relative to the fixed portion, i. e., against the action of thespring l3.

- As has been mentioned, the lug- like portions 21 and 28 are spaced apart. This of course prevents the lugs, as they move-rearwardly, from striking or otherwise interfering with the fixed cutting surface l6. Y

The inclined portion 29' of the member 29 eliminat'es the possibility that the mooring cable will catch against the forward portion of knife 23, and close the knives ahead of the cable; it assures, in other words, that the cable will ride upover the knife 23, and back against the lugs 21 and 28.

'As the cable moves rearwardly against the lugs 21 and28, causing the member H to move rearwar'dly, the knife 23 closes with respect to the fixed knife 16 upon the cable. The action continues if necessary until the lugs and the movable member strike the body member, at which point the cutting surfaces are approximately parallel and in contact with each other. The parts of the cable cutter should be soproportioned that the movable arm can not move much beyond a position perpendicular to the fixed knife. Not only is there little efiective cutting actionafter such point has been reachedybutit may beimpossible for spring 13 to return arm H to its normal position. Figures 2 and 3 show the relationship of the knives and cable just as the cutting operation is complete. It will be understood that in both figures the cable is shown more or less diagrammatically. .For in actual-operation, a cable is seldom severed as cleanly'as indicated in Figure 3, but is somewhat mashed and frayed. Ordinarily it'will not be necessary for the movable knife'to close completely on the fixed knife, sinceas' soon asthe cable is substantially weakened, the inertia and drag of the mine anchor on the one hand, and the buoyancy, inertia and drag of the mine on the other, will break the mooring cable.

- It will'be seen that the rearward movement of the'movable knife 23 is substantially greater than the closing movement thereof; and, further, that the difference between these two ratesof movement is not fixed, but that it increases as the movement of the movable arm continues. In other words, at the beginning of its travel, a unit movement of the lugs rearwardly, for example, will result in a closing of the blades with respect to each other of perhaps a half unit; the next unit of travel will produce a closing effect of perhaps three-sixteenths of a unit, etc. The difference between the rates of rearward and closing motions of the knife results in a multiplication ofthe'power of the'moving cable in theactual cutting operation, and the effect increases as the cutting. progresses. ,The' mechanical advantage atany point in the operation will: depend upon the proportions of the various parts;

After thecable 'is severed, the spring '13, re-

lieved of its load,-is enabled to return the mov able' member H to its forward position, and the cablai '1 Various types of cutting edges may be used. Two which are especially effective are shown in the drawing, and especially in Figure 4. These may be used in different combinations to advantage, depending upon circumstances. The most consistent arrangement of these cutting edges has been found to be that in which the flattened edge It forms the fixed cutting surface, and the sharpened edge 23' of knife 23 forms the movable cutting surface. This is the arrangement of the drawing. Under certain conditions, however, it

has been found that the parts function more eiiiciently when reversed. Under still other circumstances it is desirable to sharpen the edges of both cutting members.

One specific embodiment of the invention has been described and illustrated. It is obvious that many changes within the spirit of the invention can be made in the shapes and proportions of the various elements and the means for securing them together. A shearing action may, for ex-- ample, be provided in place of the nipping action resulting from the described structure. It is therefore to be understood that the invention is not limited to the device described and shown, but instead includes everything that properly comes within the scope of the appended claims.

The invention described herein may be manufactured and/or used by or for the Government of the United States of America for governmental purposes without the payment of any royalty thereon or therefor.

I claim:

1. A cable cutter comprising a fixed knife and a knife adapted to move in substantial alinement with the fixed knife and having a normal position such that the substantially alined knives form an acute angle with respect to each other and a closed position such that they are substantially parallel and substantially in contact at their edges throughout their lengths, and means cooperating with a cable to be cut for moving the second mentioned knife from its normal position toward its closed position to cut the cable.

2. A cable cutter comprising a body member with an upper portion and a lower portion, an elongated knife member in the upper portion, an arm with an upper end and a lower end the lower end being pivoted in the lower portion of the body member the upper end being provided with an elongated knife member adapted to move from one position into substantial edge-to-edge engagement throughout its length with the elongated knife in the upper portion to cut a cable, means actuated by the cable to be cut for moving the arm from its first mentioned position to its cable cutting position, and means for returnin the arm to its first mentioned position.

3. A cable cutter adapted to operate in a condition of relative movement with a cable to cut comprising a body member with an upper portion and a lower portion, an elongated knife member in the upper portion, a bifurcated member below the elongated knife and substantially parallel thereto, an arm with an upper end and a lower end the lower end being pivoted in the lower portion of the body member the upper end being provided with an elongated knife member adapted to move in the bifurcated member from one position into substantial edge-to-edge engagement throughout its length with the elongated knife in the upper portion to cut a cable, and means on the knife member of the pivoted arm adapted to be contacted by the cable to be cut and to be urged by the drag of the cable thereagainst in a direction to move the arm from its first mentioned position to its cable cutting position.

4. A cable cutter comprising a body member, a member pivoted to the body member for rotation in a substantially fixed plane and having a knife thereon, a knife fixed in the body member substantially in the plane of rotation of the pivoted member substantially at the circumferential limit thereof, means for normally maintaining the pivoted member and its knife in spaced relation to the fixed knife, means on the movable member substantially closing one end of the space and adapted to engage a cable to be cut to be moved thereby and to move the pivoted member, whereby the knife on the pivoted member is caused to close on the cable and substantially on the fixed knife surface to cut the cable.

5. A cable cutter comprising a body member, an arm pivoted near one of its ends to the body member and adapted to describe at a point in its other end an arc of a circle, a knife on the said other end substantially tangent to said arc, a knife fixed in the body member substantially tangent to the said arc, means for maintaining the pivoted arm normally spaced from the fixed knife, and means on the pivoted arm adapted to engage a cable to be out for moving the pivoted arm and the cable toward the fixed knife, thereby to cut the cable as the kmves with the cable thereloetween approach their tangential relation.

6. A cable cutter comprising a fixed knife and a knife adapted to move in substantial alinement with the fixed knife and having a normal position such that the substantially alined knives form an acute angle with respect to each other and a closed position such that they are substantially parallel and substantially in contact throughout their lengths, means for moving the movable knife toward the fixed knife at a decreasing rate with respect to the rate of angular change as between the knives, and means for restoring the movable knife to its normal position.

'7. A cable cutter comprising a body member, a knife fixed in the body member, a movable member mounted on the body member with a knife thereon in substantial alinement with the knife in the body member for movement relative thereto in the direction of the length of the edge thereof and also toward the edge thereof, and an actuating member on the movable knife adapted to engage a cable to be cut and to be moved thereby in both directions mentioned but progressively less toward the edge of the fixed knife.

8. A cable cutter adapted to cut in a condition of relative movement with a cable comprising a fixed knife and a movable knife the movable knife being normally substantially spaced from the fixed knife, and an actuating member in the space between the knives secured to the movable knife, whereby a cable entering the normal space between the knives strikes the actuating member and thereby forces the movable knife into sliding edge-to-edge cooperating relation with the fixed knife to cut the cable.

9. A cable cuter adapted to operate in a condition of relative movement with a cable to be out which comprises a fixed knife and a movable knife normally spaced from the fixed knife but adapted upon encountering a cable to be cut to be moved thereby into sliding. edge-to-edge cooperating relation with the fixed knife to out the cable.

BERNARD A. WIENER.

Images