US3515085A - Apparatus for handling floating lighters - Google Patents

Description

June 2, 1970 R. AUZINS 3,515,085

APPARATUS FOR HANDLING FLOATING LIGHTERS Filed Oct. 2, 1968 4 SheetsSheet 1 I l I i I l I INVENTOR. RAIMUN DS AUZINS Fl I BY BM, Sm,

ATTO R N EYS June 2, 1970 R. AUZINS 3,515,085

APPARATUS FOR HANDLING FLOATING LIGHTERS Filed Oct. 2. 1968 4 Sheets-Sheet 2 FIG. 2

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RAIMUNDS AUZINS BY BM, SW,

J m; 8 6m ATTORNEYS June 2, 1970 R. AUZINS APPARATUS FOR HANDLING FLOATING LIGHTERS 4 Sheets-Sheet 5 Filed Oct. 2, 1968 INVENTOR. RAIMU NDS AUZI NS ATTORNEYS June 2, 1970 R. AUZINS 3,515,035

APPARATUS FOR HANDLING FLOATING LIGHTERS Filed Oct. 2, 1968 4 Sheets-Sheet 4.

INVENTOR. RAIMUNDS AUZINS BY Bum d1, 5W,

J/mdhom 8 6m ATTORNEYS United States Patent Oflice 3,515,085. Patented June 2, 1970 3,515,085 APPARATUS FOR HANDLING FLOATING LIGHTERS Raimunds Auzins, East Avondale, Canton, Ohio, assignor, by mesne assignments, to United Industrial Syndicate, he, doing business as Morgan Engineering Company, Alliance, Ohio, a corporation of New York Filed Oct. 2, 1968, Ser. No. 764,385 Int. Cl. B63b 27/12 US. Cl. 114-435 Claims ABSTRACT OF THE DISCLOSURE A hoist mechanism for use in connection with lifting and lowering lighters respectively from and to a floating position at sea. A latch frame is suspended by rope falls for connection to the lighter and resilient members associated with the latch frame are provided for maintaining tension in the rope falls when the lighter is tossed by sea swell.

BACKGROUND OF THE INVENTION This invention relates to cranes carried on ships for lifting and transporting cargo lighters between a cargo hold and an outboard floating position. More particularly the invention relates to the hoist mechanism of the crane and especially to a means for maintaining tension in the rope falls of the hoist mechanism when a floating lighter to which the rope falls are connected is tossed by sea swell.

Since the lighters are normally loaded and unloaded at sea, some vertical motion of the lighters relative to the ship may be expected during the latching and lifting operation due to sea swell. The swell causes the lighters to toss about and rock in any number of ways. This movement makes latching diflicult and also could cause the hoist ropes to go slack during lifting or lowering and then snap taut as the swell recedes, thus putting an undesirable shock load on the hoist mechanism. More importantly the slack hoist ropes could become entangled with the pulleys and crane structure and cause serious damage to the hoist mechanism.

A swell compensating device for maintaining tension in the hoist ropes while the cargo lighter is tossed by sea swell, is disclosed in US. Pat. No. 3,390,657. According to that device, resilient members associated with each rope fall are interposed between a latch frame and the crane body to maintain tension in the rope falls even while the floating lighter is being tossed about in the sea.

The apparatus of the present invention is an improved form of the type of swell compensating mechanism of US. Pat. No. 3,390,657 and affords features and advantages not obtainable from the prior art.

SUMMARY OF THE INVENTION It is among the objects of the invention to maintain tension in rope falls connected between a crane and a floating lighter while the lighter is being tossed by sea swell.

Another object is to connect the rope falls of a hoist mechanism to a latch frame adapted for connection to a floating lighter, through a load bearing connection mechanism which accommodates tossing of the floating lighter and the latch frame connected thereto while still maintaining tension in the rope falls.

Still another object is to reduce the impact between a latch frame of the type described and a floating lighter during connection of the latch frame to the lighter.

These and other objects are accomplished by means of articulate flexible knee joints mounted on a latch frame suspended by the rope falls of a hoist mechanism for lifting and lowering lighters respectively from and to a floating position at sea, the latch frame being adapted for connection to the lighter. Each knee joint comprises a pair of pivotally interconnected links, one link carrying sheaves at its outer end, which are operably connected to the respective rope fall and the other link being pivotally connected to the latch frame coaxially with the sheave axis and the axis of the joint. The knee joint is bendable between a load bearing position with the links generally in vertical alignment end-to-end with one another and a collapsed or bent tension maintaining position. The joint is biased to its collapsed position to such an extent that it is partially collapsed by the weight of the latch frame alone. The biasing means is operable to collapse the joint with the outer ends of the links remaining substantially in vertical alignment with one another relative to the plane of the latch frame. Accordingly, each joint is effective to maintain tension in its respective rope fall when the lighter to which the latch frame is attached is being tossed by sea swell.

In the preferred embodiment the biasing means comprises a bell crank secured to the upper link and pivotable coaxially with the head pin of the knee joint. A collapsing or rope tensioning force is applied to the bell crank at a point angularly disposed relative to the upper link itself in a manner tending to collapse the joint with the sheave axis and latch frame pivot axis remaining in generally vertical alignment with one another relative to the latch frame.

As another aspect of the invention two knee joints are mounted on each of two load beams forming opposite ends of a rectangular latch frame. The joints are arranged to collapse in a plane parallel to the load beam and the beams are each latched to two respective corners of the lighter. The load beams are linked together at pivotal connections by spaced longitudinal side members which permit the load beams to move out of coplanar relationship with one another and also to remain in the same plane as their respective rope falls when one load beam is lower than the other.

The beams have pyramid shaped recesses which fit over pyramid shaped latching posts on the lighters and latch bolts on the load beams are inserted in closed lateral slots in the posts to secure the load beams to the lighters for lifting. To compensate for rocking movement of the lighter in a plane perpendicular to the load beams, the opposite side walls of each recess, that are parallel to the longitudinal centerline of the respective load beam, are of a convex cross section as is the floor of the recess. The convexities of these surfaces are interrelated so as to provide line contact between each post and its respective recess, along three parallel lines throughout a suitable range of rocking movement of the lighter relative to each load beam in a plane perpendicular to the load beam. Rocking movement of the lighter in a plane parallel to the load beam, however, is compensated for by the knee joints themselves.

Other objects, uses and advantages of the invention will be apparent from the following detailed description and drawings which describe and illustrate a preferred form of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevation of the stern of a ship having a traveling gantry crane positioned on cantilever stern beams with its hoist mechanism ready to lift a floating lighter from an outboard position at the stern of the ship;

FIG. 2 is an end elevation on an enlarged scale showing the latch frame of the hoist mechanism connected to a floating lighter being tossed by sea swell;

FIG. 3 is a side elevation on an enlarged scale taken from the plane indicated by the lines 3-3 of FIG. 2;

3. 7, FIG. 4 is a sectional view on an enlarged scale taken on the lines 4-4 of FIG. 5;

FIG. 5 is a fragmentary plan view showing a portion of the floating lighter and latch frame of FIGS. 1 and 2; and FIG. 6 is a sectional view on an enlarged scale taken on the lines 66 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings FIG. 1 shows a transport ship A adapted to carry cargo lighters such as a lighter B shown floating at the stern of the ship. The ship A has a gantry crane C located for travel on spaced rails extending longitudinally along opposite sides of the ship. In FIG. 1 the gantry crane C is located on spaced cantilever stern beams D which provide a platform on which the crane may travel to an outboard position shown in FIG. 1 for lifting and lowering the lighter B respectively from and to the sea. The gantry crane C is similar to the crane shown in copending' US. application Ser. No. 721,821, filed Apr. 16, 1968 and will not be de scribed in detail.

The hoist mechanism of the crane includes four rope falls 10 suspended from stationary sheave nests 11 at the top of the crane C. Each rope fall 10 is connected to one of four hoisting sheave nests 12, one sheave nest being connected to each of four articulate collapsible knee joints E embodying the invention and located at each corner of a latch frame 13 adapted for connection to the floating lighter B. The rope falls 10 each comprise two hoist ropes which pass back and forth between a stationary sheave nest 11 on the crane and a respective hoisting sheave nest 12 operatively connected to the latch frame 13 through a collapsible knee joint E.

The latch frame 12 comprises starboard side and portside load beams 14 which are linked together at pivotal connections by tubular members 15 to form an articulated rectangular skeletal frame. Diagonal brace cables 16 prevent collapse and twisting of the frame, however, the pivotal connections between the load beams 14 and tubular members 15 permit the opposite load beams 14 to move out of coplanar relation to one another and also to remain in vertical alignment with the rope falls when the lighter is rocked in a plane perpendicular to the load beams 14.

At opposite ends of each load beam 14 is a latch mechanism (FIG. 4) comprising a pyramid shaped recess 17 adapted to match the tapered top portions of posts 18 located at each corner of the lighter B. The tapered configuration of the posts 18 and recesses 17 in the latch frame 12 assures accurate alignment of the latch frame 13 relative to the lighter B and also permits the crane operator some margin of error in dropping the latch frame 13 into position, the recesses 17 serving as a centering and locating means. This arrangement is described in detail in U.'S. application 'Ser. No. 721,821 identified above.

The tapered top of each post 18 is provided with a horizontal closed slot 21 which is adapted to receive a latch bolt 22. The latch bolt 22 is operated by a threaded rod 23 which in turn is moved in an axial direction by a gear reducer unit 24 driven by an electric motor 25. Alternatively, however, the latch bolt may be operated by a hydraulic cylinder.

Referring to FIG. 2 it will be seen that when the lighter B rocks or tilts in a plane perpendicular to the load beams 14 the posts 18 must also rock or tilt a corresponding amount within the recesses 17. Otherwise the load beams themselves would roll with the lighter about their longitudinal centerlines and the sheave nests 12 would move out of vertical alignment with their respective rope falls 10.

In order to accommodate this rocking movement, the opposite side walls 19 of the recesses 17 are parallel to the longitudinal centerline of the respective load beams 14 are of a convex. cross section as is the floor of the recess '(FIG. 6). The convexities of these surfaces are interrelated so as to provide contact between these three convex surfaces and the respective post, along three lines of contact throughout the design range of rocking motion of the lighter in a plane perpendicular to the load beams. This three point contact is illustrated in FIG. 2 where the lighter is rocked-to approximately the-design limit of the hoist mechanism. It will be seen that the load beams 14 have rolled relative the lighter B about their longitudinal centerlines in order to remain in the vertical planes of their respective rope falls 10.

Each hoisting sheave nest 12 is connected to the latch frame 13 by one of the articulate collapsible knee joints E, two of which are located on each load beam 14 for collapsing movement in a vertical plane through the longitudinal centerline of their respective load beam 14. The joints E serve to maintain tension in the rope falls 10 when the latch frame 13 is latched to a floating lighter B being tossed by sea swell such as during the lifting and lowering of the lighter B respectively from and to a floating position at sea. The joints also accommodate rocking movement of the lighter B in a plane parallel to the longitudinal centerline of the load beams.

The collapsible knee joint E is best shown in FIGS. 4, 5 and 6 and includes an upper link 30 to which the sheave nest 12 is pivotally connected by a sheave pin 31, the link 30 being bifurcated to receive the hoisting sheave nest 12 as best shown in FIG. -6. The link 30 is pivotally connected by a head pin 33 to a bifurcated lower link 34 which in turn is pivotally connected at its lower end by pins 35 to one of the load beams 14.

The joint E is movable between the extended position shown in FIG. 1 and in solid lines in FIG. 4 and a collapsed position shown in dashed lines in FIG. 4. Thus the sheave nest 12 is capable of generally vertical movement between the position shown in solid lines in FIG. 4 and the position shown in dashed lines in FIG. 3 in order to maintain tension in the rope falls 10 when the barge is tossed upward by the sea swell.

Each joint E is biased to its collapsed position by a tensioning cable 36 connected to a bell crank 37 secured between the bifurcations of the upper link 30 (FIG. 6). The cable 36 passes around an arcuate arm 38 of the bell crank 37 to a'connection point. By applying a force to the bell crank with the tensioning cable 36, the collapsing movement of the joint E (FIG. 3) is accomplished essentially without moving the axis of the sheave nest 12 out of vertical alignment with the axis of the hinge pins 35 which connect the lower link 34 to the latch frame 13. The biasing force tends to pivot the upper link 30' about the head pin 33 out of vertical alignment so that both links 30 and 34 move through about the same angular displacement.

The collapsing movement is limited by a bumper 39 lo cated on the beam 14 which engages a matching stop 40 on the lower link 34. It will be seen that the cable 36 is wrapped about the arcuate arm 38 of the bell crank 37 so that the tensioning force is always applied to the upper link 30 with substantially the same mechanical advantage throughout the collapsing movement. 1

The cable 36 is tensioned by one of two air loaded tensioning cylinders 41 mounted on a bracket 42, one of which is recessed within each load beam 14. Each air cylinder 41 serves to tension a single length of tensioning cable 36 that is operatively connected to both of the knee joints E mounted respectively on one of the load beams 14. Thus one air cylinder 41 is provided for each load beam 14.

The tensioning cable 36 extends from its point of attachment to the bell crank 37 to one of two stationary pulleys 43 secured within the load beam 14. From one of the pulleys 43 at the rearward end of the air cylinder 41, the cable 36 passes back to and from another pulley 44 mounted on the piston rod 45 of the cylinder 40. The cable extends back and forth several times between the pulleys 43 and 44 and thence to the opposite knee joint E.

The air cylinders 41 are loaded to 'a predetermined pressure so that the tensioning force or resiliency is sufficient to' partially collapse the joints E under the weight of the latch frame 13 alone and is also sufficient to maintain a tensioning force acting on the joints throughout their range of movement.

A secondary advantage of this arrangement is that the latch frame itself stores considerable potential energy tending to counteract the weight of the latch frame. Therefore during the latching operation the impact of the latch frame 13 engaging the lighter B is considerably reduced thus greatly extending the life of the latch frame and its associated mechanisms.

OPERATION The operation of the knee joints B will be described with respect to a latching operation wherein the hoist mechanism of the gantry crane C lowers the latch frame 13 onto a floating lighter B positioned at the stern of the ship A as shown in FIG. 1. During the lowering of the latch frame the knee joints E are partially but not fully 6 in the reverse manner and again the knee joints are effective in the same way to maintain tension in their respective rope falls when the lighter is in a floating position and being tossed by sea swell before the latch frame 13 is released.

While the invention has been shown and described with reference to a specific embodiment thereof, this is intended only for the purpose of illustration rather than limitation and other variations and modifications will become apparent to those skilled in the art within the intended spirit and scope of the invention as herein specifically illustrated and described. Therefore the patent is not to be limited in scope and effect to the preferred form illustrated and described herein nor in any other way that is inconsistent with the progress by which the art has been advanced by the invention.

extended due to the weight of the latch frame. The

eventual impact of the corners of the latch frame 13 with the posts 18 on the lighter is softened considerably due to the potential energy stored in the air cylinders 41. Once the latch frame 13 is in position on the posts 18 the motors 25 are operated to move the latch bolts 22 into their respective slots 21 and thus secure the latch frame 13 to the lighter for lifting. Once the latching is complete the hoist mechanism may be operated to lift the lighter B from the sea.

Before the lighter B is lifted out of the sea however certain tossing movement of the lighter relative to the ship can be expected as illustrated in FIGS. 2 and 3. It will be seen that without the articulate collapsing knee joints E the rope falls 10 would be periodically slackened due to the sea swell. However, according to the present invention tension is maintained in the rope falls 10 due to the collapsing movement of the joints E.

Referring to FIG. 3 for example it will be seen that the left-hand side of the lighter has been tilted upward to raise the respective end of the latch frame 13 relative to the hoisting sheaves 12 of the rope falls 10 immediately above. As this occurs however the respective knee joints E collapse to maintain tension in the rope falls.

The collapsing action is accomplished in such a way that the axis of each hoisting sheave nest 12 remains in generally vertical alignment with the hinge pins 35 conmeeting the respective lower link 34 to the latch frame. This obviates any excessive swinging movement of the rope falls during the collapsing movement. The force causing the collapsing movement is supplied through the compressed air cylinders 41 which tension the cable 36 and thus maintain a desired biasing force in each knee joint B.

As indicated above the lighter may rock in any number of ways and is not limited to uniform vertical movement with the sea swell. The rocking or tilting movements shown in FIGS. 2 and 3 are typical. When the tossing lighter B causes the load beams 14 to be tilted endwise as shown in FIG. 3, the joints E compensate for the movement since they collapse unequally in the vertical plane through the longitudinal centerline of their respective load beam.

When the lighter B rocks or tilts in a plane perpendicular to the load beams 14, however, the load beams must roll relative to the lighter, about their respective longitudinal centerlines in order to stay in the vertical plane of their respective rope falls. This rolling movement (FIG. 2) is accommodated by means of the unique shape of the pyramid shaped recesses 17 wherein the opposite side walls 19 of the recess as well as the respective floor thereof are convex and thus accommodate tilting or rocking movement of the posts 18 received therein as indicated in FIG. 2.

The lowering of the lighter into the sea is accomplished What is claimed is:

1. In a hoist mechanism for lifting and lowering lighters respectively from and to a floating position at sea, the mechanism including a plurality of rope falls and a latch frame suspended by said rope falls and adapted for connection to a lighter, the improvement which comprises a collapsible member for each rope fall, said member being operatively connected between its respective rope fall and said latch frame and being movable between an upwardly extending load bearing position and a collapsed tension maintaining position, and means biasing said member to said collapsed position to maintain tension in its respective rope fall when said latch frame is connected to a lighter being tossed by sea swell.

2. Apparatus as defined in claim 1 wherein said latch frame is of rectangular skeletal form and comprises a pair of laterally spaced generally parallel load beams linked together at pivotal connections by spaced side members, one of said collapsible members being mounted at each end of each load beam for collapsing movement in the vertical plane through the longitudinal centerline of its respective load beam, a recess of pyramidal form in the bottom of each load beam at each end thereof and adapted to receive a post top of pyramidal form on a corner of said lighter, each recess having opposite surfaces parallel to the longitudinal centerline of the respective load beam, said surfaces having a convex form to provide line contact with the adjacent surfaces of the respective post whereby to accommodate lateral roll of said load beam relative to said lighter, and latch means on each load beam cooperable with the respective posts for securing said load beams to said lighter for hoisting.

3. Apparatus as defined in claim 1 wherein said biasing means comprises a pneumatic cylinder.

4. In a hoist mechanism for lifting and lowering lighters respectively from and to a floating position, the mechanism including a plurality of rope falls and a latch frame suspended by said rope falls and adapted for connection to a lighter, the improvement which comprises an articulate collapsible knee joint for each rope fall, said knee joint comprising a pair of pivotally interconnected links, one link being operatively connected to its respective rope fall and the other link being pivotally connected to said latch frame, said joint being bendable between a load bearing position with said links in vertical alignment, and a collapsed tension maintaining position, and means biasing said joint to said collapsed position to maintain tension in said rope fall when said latch frame is connected to a lighter being tossed by sea swell, said means being operable to bend said joint with the outer ends of said links remaining substantially in vertical alignment with one another relative to said latch frame.

5. Apparatus as defined in claim 4 wherein said biasing means includes a bell crank secured to said upper link and coaxial with said knee joint, and a tension cable connected to said bell crank and adapted to exert a collapsing force through said bell crank on said knee joint.

6. Apparatus as defined in claim 5 wherein said bell crank is provided with a curved end surface on the bell crank arm to which said'tension cable is connected, said curved end surface being concentric with th'e b ell crank axis and said tension cable being wrapped around said end surface whereby the moment of force of said tension cable about said bell crank axis remains. substantially the same throughout said collapsing movement.

7. Apparatus as defined in claim 4 wherein said biasing means comprises an air cylinder. I

8. Apparatus as defined in claim 7 wherein said air cylinder is pre-loaded sufiiciently to partially collapse said knee joints under the weight of said latch frame alone. Y

9. Apparatus as defined in claim 4 wherein'said latch frame is of rectangular skeletal form and comprises" a pair of laterally spaced, generally parallel load beams linked together at pivotal connections by spaced side members, one of said knee joints being mounted at each end of each load beam for collapsing movement in the vertical plane through the longitudinal centerline of its respective load beam to accommodate endwise tilting movement of said load beam when latched to a lighter, and means for accommodating lateral roll of said load beams relative to said lighter whereby said load beams remain generally in the Vertical plane of their respective rope Ifalls when said lighter is rocked in a plane perpendic'ularto said load beams. j I

10.- Apparatus as defined in claim 9 wherein said means for accommodating lateral roll comprises a recess of pyramidal form in the bottom of each load beam at each end thereof andadapted to receive a post top of pyramidal form on a corner of said lighter, each recess having opposite surfaces parallel to the longitudinal centerline of the respective load beam, said surfaces having a convex form to provide line contact with the adjacent surfaces of the respective post.

I References Cited v v UNITED STATES PATENTS 3,361,274- 1/1968: Goldman 214 1s 3,428,194 2/1969 Weiss 214-1s TRYGVEcMi BLIX, Primary Examiner us; c1 X.R. 214-15

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