US2381665A - Obstacle plow - Google Patents

Description

.Aug. 7, 1945.

A. J. HIGGINS, JR

OBSTACLE PLOW Filed July 24, 1944 3 Sheets-Sheet 1 Aug. 7, 5- A. .1. HIGGINS, JR

OBSTACLE PLOW Filed July 24, 1944 3 Sheets-Sheet 2 7, 1 945. A. JQHIGGINS, Jk

OBSTACLE PLOW 3 Sheets-Sheet 3 I Filed July 24, 1944 Patented Aug. 7, 1945 UNITED PATENT DFFICE v :oBsrAcLE PLOW y: Andtewl'H-iggiins, Jr., New Orleans, La. Application miner, 1944, SexialNo. 546;282 reclaims. (c1. arr-.219

This invention relates to :an nbsta'cle plow particularly designed as equipment for p'owered landing cra'ft in'fforcing aflanding on hostile beaches defended by various types of offshore obstacles calculated to tear the 'bottoms out of the landing 'craftror iotherwise preventthem from reaching the shore. The invention is especially adapted for that type {of shallow 'draift broad bowed landing credit which slides up onto the beach under power .for discharge of its personnel or cargo.

The general object of the invention is to pro- "vide an obstacle plow .of such width as to .em-

brace the entire width of the bow, arranged forwar'dl'y of the bow, "capable of ibeing Jhelcl inele- 'vated position out of water, in, which position it offers'no impediment to navigation, andadapted to be'lowere'dto and held in vapositio'n'in .protec- "tiverelation to the submerged bottom with .its convergent obstacle engaging apex shallowly submerged.

Anotherobject of the invention-is [to provide an obstacle plow. as described, pivotally mounted at the sides of the hul1,;permitting it to be alternately elevated, or lowered to working position, with means .ior locking it in working position soflthat it presents a positive unyielding thrust to the obstacle-tube breached, and will not lift upon enga ement with the obstacle.

Aiu-rther object of the .inventionisto provide a pivotallymounted obstacle plow .as described, in which the locking means are readily removed or released so that the plOW. maybe; unlocked after the obstacle has been cleared; permitting the .plow to lift automatically upon contact with. the shelving beach so that the craft can i be .properly landed. v

Still another :object of the invention is toprovide means for releasing "the connections ot-the plowiwit'h the =landin'g craft, permitting the .plow to be completely dropped from the craft, should iSllCh necessity arise.

A still further object of'the invention is to provide an obstacle plow having divergent fenders below the obstacle engaging apex, arranged in protective relation to the submerged forward part of the craft for divertingsuc'h portions "of the obstacleas may be overrun by the'attacking" apex.

A *further object of the invention is 'to'make "the plow automatically "releasable irom the landing craft; upon its encountering an immovable obstruction such as an abruptly rising bank or shore. r

Other objects or the invention will appear "as the following description o'f apreferred andi ractica-l embodiment thereof pro ceeds.

In the drawings which accompany and iform a part of the following specification, and throughout the several *figu'res "of which the same reference characters have 'been employed to :denote identical parts: i

'Figure 1 use side elevation o'i the .forward :portion of a landing 'crai-tgshow ing 'thezobstacle plow in working position;

Figure 2 is a plan view or Figure 1;

Figure 3 is a cross-section through the con- 'necting means, taken along the line 3-3 of iEi'g- Figure '4 is "a"cross-section'takenalong the line .4-4?of'Figure3";

Figure -5'is a side elevation of the releasing winch;

' Figure '6 is a'n 'end'elevationof "the winch shown in Figure 5;

Figure '7 is apersp'ectlve "view of the locking bracket;

Figure 8 is a diagrammatic planota landing craft with obstacle plow attached, the forward ,portion "of the plow being omitted, showing a convenient location for the releasing winch and the flexible connections -therefrom tothe plow;

Figure!) is aperspective'viewshowing the construction at the rear 'end of the side members.

Referring now in detail to the several figures,

thenumeral l represents a landin'g craft of the shallow draft typejhavin'g the broad bowfi closed by a ramp 3, which-swings down *upon "the beach after the crafthas landecl, to permitthe discharge or the personnel or the mechanized equipment. Such craft are "employed in landing upon hostile beaches "where there are no dock facilities, the

.craft s'liding'up upon the beach under power.

"suchbeaches "are frequentlydefended by offshore obstacles, the tops of which are just submerged at high tide and calculated either to tear the bottom out of the landing 'craft or :to hang them up upon said obstacles, to prevent them 'fromreach'ing the shore. Two-types of such obstacles may be mentioned, barriers fabricated of logs eitherdr-iveninto thecsea bottom-unweighted to keep them in place, or concrete imasses resting upon the sea bottom, 'in which sections of steel rai1- are east with their sharp or jaggeden'ds upstanding.

The subject invention proposes to equip such landing "craft with aforwardly positioned obstacle plow which attacks such obstacles under the powerof the craft, either rending or disintegrating the log barriers, or turning them aside, 'or'upsetting or pushing aside the steel rail barriers to provide a passage therebetween for the landing craft. The plow in general is designated by the reference character 4. As illustrated, it consists of a pair of rearwardly divergent bars 5 forming a working apex 6 at the front and separated sufficiently at the rear to embrace the entire width of the bow of the landing craft. Side members extend from the rear ends of the bars 5 substantially longitudinally along the sides of the landing craft, spaced therefrom, having pivotal connections with the sides of the landing craft represented by the coaxial pins 8 (see Figures 1, 2 and \3), the details of which connections will be described in due course. extend-toward the rear beyond said pivotal connections to provide for holding and locking the plow in working position, as will presently be explained.

The plow comprises also the rearwardly extending midrib 9, secured to the divergent bars 5 adjacent the apex 6, and extending divergently rearwardly below the horizontal plane of said side bars so as to form with said side bars a trihedral angle at the apex. A pair of rearwardly divergent fender bars l are connected to the midrib 9 at an intermediate point, and another pair of rearwardly divergent fender bars H, at its rear end. Both pairs of fender bars lie in planes which diverge rearwardly downward from the plane of the side bars 5. The divergent ends of the fender bars H] are connected to the side members by the struts l2 and the divergent ends of the fender bars II are connected to said side members by the struts I3 at points forwardly of the connecting means and the ends of the fender bars II are also connected to the side members 1 rearwardly of the locking means by the upwardly inclined extensions l4. The fender bars H) are also connected to the side bars by the inclined struts l5. Thus, the plow forms a strong threedimension girder construction.

As illustrated, the obstacle plow and its appurtenant parts are fabricated by welding, a mode of construction which involves the employment of The side members structural expedients which would not be resorted to under some other mode of construction. Since themanner of making this obstacle plow is not particularly important to the invention, these details peculiar to welding need not be described. By way of example, the side bars 5 are welded to the side members at the joint I6, involving the use of the strengthening members I1, which lap said joint and are welded to the adjacent members.

In order to connect the obstacle plow pivotally to the sides of the landing craft, the latter is provided with the brackets, in general designated by the reference character l8 and shown in detail in Figures 3 and 4. Each bracket comprises a back plate l9 secured to the side of the craft in any suitable manner as by the rivet plugs 20, Figure 1. Since this plate is called upon to resist the thrust of the plow against the obstacle, the connection must be quite strong. For example, the rivet plugs 20 may be four inches in diameter. A housing having the form of an inverted channel extends outwardly from the plate I9, said housing comprising the spaced vertical inner and outer side plates 2| and 22 connected by a top plate 23. Said housing is overlain by an inclined brace plate-24, connected at its upper side to the back plate l9 and at its lower side to the top of the outer side plate. 22. The brace plate 24also serves as a protective cover for the .sheave25,

which is journaled on a pin carried by a lug 26 secured to the top plate 23.

The side plates 2| and 22 are provided with vertical pin receiving slots 21 for the pivot pins 8, which pass horizontally through the side members 1 of the plow, forming extensions on both sides thereof. Said pins are suitably secured to the side members as by welding.

Operable within the housing is the latch member, as a whole designated by the numeral 28, consisting of the side plates 29 and 30, connected by the angular bridge piece 3|. The side plates 29 and 30 are provided with journal blocks 32 and 33 journaled in suitable bearing recesses in the side plates 2| and 22. The side members, including the journal blocks, are provided with the pin receiving slots 34. In the norma1 position of the latch member 28, shown in Figure 4, the slots 34 are at right angles to the slots 21, so that the pin 8 is retained within the housing. The side plate 30 of the latch member 28 is formed with a cable receiving groove 35, in which lies a cable 36, the end of which passes through an eye 31 formed on the lower face of the side plate 30. The cable passes through a hole 38 in the top plate 23, around the sheave 25, through registering holes 39 and 40, respectively, in the back plate l9 and the side of the boat, from which point it may pass to the deck of the landing craft, then about direction changing pulleys or fair-leaders 4| to Blge winch, designated as a whole by the numeral The winch is shown in detail in Figures 5 and 6 and comprises a base 43 having spaced bearings 44in which is journaled the shaft 45 of a drum and ratchet member 46. The drum is preferably hollow and has a hole 41 for securing the end of the cable 36, which is passed through the hole 41 and knotted on the inside of the drum. The winch includes a holding pawl 48 and a winding pawl 49 pivotally secu ed to the hand lever 50 which is rockable about the shaft 45. By winding the cable on the drum 46 the latch member 28 is rotated to a position in which the slots 34 coincide with the slots 21, whereupon the pin 8 drops out, disconnecting the plow from the landing craft. Normally, when the cable 36 is unwound or released by lifting the holding pawl 48, the offset weight of the latch member 28 returns it to the position shown in Figure 4.

It is noted from Figure 8 that the winch 42 simultaneously operates cables leading to opposite latch members, so that both pins 8 are simultaneously released.

The means for positioning the obstacle plow in its lowered or rocking position and for locking it in such position are located rearwardly of the connecting means and so placed as to give the side members and side bars 5 of the plow a general downward inclination in a forward direction, whereby the Working end of the plow is submerged and the plow interposed in protective relation to the submerged portion of the boat hull. The locking means are shown in detail in Figure 7. Each consists of a back plate 5| secured to the side of the landing craft by one or more rivet plugs 52. Spaced upright side members 53 and 54 extend in a transverse direction outwardly from the back plate 5|. These support a semicylindrical socket member 55 adapted to receive the ends of the extended portions 56 of the side members The outer end of each socket member 55 is obstructed by means of chordally disposed plates 51 secured thereto. Any other form of obstructive means would be the equivaready to attack the obstacle.

aesncco with a flat vertical clip 58 welded across the ex tension in its vertical diametrical plane and having a rearwardly opening pin slot 59. Said clip extends between the spaced lug 60 formedon the rearward face of the plate 53, and having rearwardly opening pin slots 6| with which the slot 59 and the clip 58' registers. Detainin springs 62 guard the entrances to the slots 6|. A double headed pin 63 may be pressed endwise a ainst the tension of the springs 62 into the aligned slots GI and 59 to lock the obstacle plow in its working position. When it is desired to remove the locking pin 63, this may be readily done by pulling it through the open ends of the slots against the tension of the springs 62.

The side members of the plow, including the extensions 56, are provided with streamlined deflectors 64, to divert portions of the obstacle which may be sliding along the side members of a plow, from engaging and damaging the respective connecting and. locking instrumentalities attached to the outside of the sides of the landins craft.

A block and fall 65 is connected to the obstacle plow at a convenient p int forward of its pivotal connection with the landing craft, the rope of which may pass through the ramp and be conveniently located along the deck. Normally,

when he craft is: navigated in open water the pin 63. is not in place and the plow is, drawn up by the block and fall, swingin about its pivotal connection to a position against the bow portion or the craft, where it is entirely above the water line and offers no impediment to the prog" ress of the craft. When the beach to be invaded isv approached, the plow is lowered by. means of he block and fall, swinging about th pivotal connection. 8 until the ends of the extensions 56 enter the sockets 55, with the clips 58 between the lugs 60 and the slots 59 and GI in alignment- The sockets 55. act as stops to determine the low- I errnostj. or workin position of the plow. Members of the. crew, reaching over the side of the boat. then put the pins. 63 in lace, looking the plow in its. working. position so. that it is now strihes the obstacle under the full power of the landin crait, it either rends; or pushes aside the obstruction, the. latter being diverted. by the side bars 5 and side members 1- 0f the plow, to. clear a path of sufficient width forthe passage of the landin craft through the barrier. Any part of the obstacle overrun by the plow is diverted laterally by the divergent. fender bars Ill and H out. of the path of the submerged portion. of the hull. cleared. enough poll is. put: upon the block and falt 65. to takethe weight of the plow ofiof the pins; 53,. which are. removed by crew members. The plow is then in position for landing; It is noted that the apical portion 6 of the plow is upturnedso that it will. be upwardly deflected upon contact. with, the beach and not dig into the; sand... As the. landin craft; rides up upon the; each, the plow automaticall tiltsabout its pivotal onnections 8 and affords. no, resistance When the plow lmmediatel-y'upon the obstacle. having been to theproper landing of the craft. The ramp may then be let down over the plow and the personnel or equipment discharged over the ramp.

There may be times when the presence of the plow acts as a drawback, so that it may be desirable to quickly disconnect it completely from the landing craft. For example, a plow may occasionally become fouled upon the obstacle so that the craft is hung up and unable to make a landing or get away. Under such circumstances the plow may be quickly disconnected by cutting the rope of the block and fall and operating the winch to cause the releasing member 23 to drop the pins 8. When the pins 8 are out of the slots 21, a very slight forward movement of the craft will release the pins 63 from the slots 62 and the landing craft is entirely free from the plow. Sometimes the beach may be so precipitous that the plow would assume an elevated position, preventing the proper descent of the ramp, in which case it may be desirable to lose the plow before the landing craft finally grounds upon the beach. Occasionally it may be desired to drop the plow in deep water, in which case, when the rope of the blockand fall has been cut and the pins 8 released, the plow will sink to a vertical position, whereupon the slots 59 will slip from the pins 63 and the plow be entirely freed from the landing craft. As a factor of. added flexibility in the use. of the obstacle plow, it is preferred to make the pins 8 and 63 as shear pins so that if the plow encounters an immovable obstacle it may, according to the nature of the encountered obstruction, break the pin BI and ride over the obstruction or break the pin 8 and become released from the landing craft.

While I have in the above disclosure described what I believe to be a preferred and practical embodiment of the invention, it may be understood to those skilled in the art that the details of construction as shown and described are only one of the 'many ways in which the invention can be embodied, and not to be construed as limiting the scope of the appended claims.

What I claim as my invention is:

l. Obstacle plow adapted to be mounted in front of. the bow of a landing craft, comprising side members convergent forwardly to an apex and spaced apart. at the rear to a width greater than that of the bow and extending rearwardly along the sides of the bow,.means for pivotally connecting said plow to said landing craft on a horizontal transverse axis at intermediate points of said side members, and stop means secured to said, landing craft rearwardly of said connecting means, engageable with the rearwardly extending portions of said side members for determining the working position of said plow.

2 Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising side members convergent forwardly to an apex and spaced apart at the rear to a width greater than that of the bow, means for pivotally connecting said plow to said landing. craft at both sides on a horizontal transverse axis, and means for simultaneously releasing said plow from both its pivotal connections.

points of said side members, means for simultaneously releasing said plow from both its pivotal connections and stop means secured to said craft rearwardly of said connection means, engageable with the rearwardly extending portions of said side members for determining the working position of said plow.

4. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising side members convergent forwardly to an apex and spaced apart at the rear to a width greater than that of the bow, mean for pivotally connecting said plow to said landing craft, comprising hearing members fiXed to said landing craft at opposite sides, and coaxial transverse pins carried by said side members, journaled in said bearing members, and means operable at will for releasing said pins from said bearings.

5. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an openwork girder frame opposing minimum resistance to water displacement, including a pair of side members convergent forwardly to an apex and spaced apart at the rear to a width greater than that of the bow, and pivotally connected to the landing craft to permit the plow to be raised or lowered, a median longitudinal member extending from said apex downwardly and rearwardly divergent from the transverse plane of said side members, a pair of fender bars convergent to an apex at a point in said median longitudinal member divergent rearwardly and downwardly, and struts connecting said fender bars to said side members, said plow having a working position in which the forward end is shallowly submerged and in which the fender bars are in protective position forward of the submerged portion of the bottom of the craft.

6. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging and bottom protecting member forwardly convergent both transversely and upwardly, having side members extending along the sides of the landing craft, means for pivotally connecting said plow to the sides of the landing craft at coaxial intermediate points in said side members, and stop means on the sides of said landing craft above the inner end portions of said side members, engaged by the latter determining the working position of said plow in which the forward end is shallowly submerged, said plow being freely swingable upward from its working position upon contact with a shelving beach.

7. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging and bottom protecting member forwardly convergent both transversely and upwardly, having side members extending along the sides of the landing craft, means for pivotally connecting said plow to the sides of the landing craft at coaxial intermediate points in said side members, said connecting means comprising cooperating bearing and journal means carried by said side members and landing craft, means operable at will for releasing said journal means from said bearing means for disconnecting said plow from said landing craft, and stop means on the sides of said landing craft above the inner end portions of said side members engaging the latter, determining the working position of said plow in which the forward end is shallowly submerged, said plow being freely swingable upward from its working position upon contact with a shelving beach.

8. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging forwardly convergent member having side members adapted to embrace the sides of the landing craft, intermediately pivotally connected to the sides of said landing craft, means engageable by the free end portions of said side members determining the working position of said plow, said means being constructed and arranged to permit said plow to swing freely upward from its working position, and means operable at will for fixing said plow in working position.

9. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging forwardly convergent member having side members adapted to embrace the sides of said landing craft, intermediately pivotally connected to the sides of said landing craft, brackets fixed to the sides of said landing craft having portions above the free end portions of said side members, engageable thereby to hold said plow in normal working position so constructed and arranged as to permit said plow to swing freely upwardly upon engagement with a shelving beach, the free ends of said side members, and said brackets having apertures, aligned when said plow is in working position, adapted to receive a pin for locking said plow in working position.

10. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging forwardly convergent member having side members adapted to embrace the sides of said landing craft, intermediately pivotally connected to the sides of said landing craft, brackets fixed to the sides of said landing craft having downwardly opening sockets above the free end portions of said side members engageable thereby to determine the working position of said plow but permitting it to swing freely upwardly upon engagement with a shelving beach, each bracket .being provided with spaced lugs having transversely aligned open ended slots with spring detents restricting the mouths of said slots, the free ends of each side member being provided with a portion interdigitating with said lugs and having the open ended slot registering with said lug slots when said plow is in working position, and a pin adapted to be manually pushed laterally past said detents into said aligned slots for locking said plow in working position.

11. Obstacle plow adapted to be mounted in front of the bow of a landing craft, comprising an obstacle engaging forwardly convergent plow member, having side members adapted to embrace the sides of said landing craft, pivotally connected to the sides of said landing craft, the pivotal connections comprising transverse coaxial pins carried by said side members and brackets carried by the sides of said landing craft, latching members journaled in said brackets having open ended slots receiving and normally supporting said pins, means operable at will for rotating said latching means to bring said slots to a position in which said pins are dropped from said latching means disconnecting said plow from said landing craft, means for lowering said plow to submerged working position or raising it to an unsubmerged position, and means for limiting the normal range of lowering movement of said plow to its working position.

12. Obstacle plow adapted to be mounted in front of the bow of a landing craft comprising an obstacle engaging forwardly convergent plow member having side members adapted to embrace the sides of said landing craft and pivotally connected to the sides of said craft, the pivotal connection including transverse coaxial pins carried port and retain said pins in said bracket slots,

by said side members, and brackets carried by the 7 means for rotating said latching means to bring side of said landing craft, said brackets having the slots of said latching means into alignment downwardly extending pin receiving slots open at with the bracket slots whereby said pins are their lower ends, latching members journaled in 5 gravitationally dropped from said aligned slots, said brackets having open ended pin receiving disconnecting said plow from said landing craft. slots cooperating with said bracket slots in the normal position of said latching means, to sup- ANDREW J. HIGGINS, JR.

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