US3662991A - Crane device for preventing collision of load with seacraft in rough weather - Google Patents

Abstract

A device mounted on a crane particularly a floating crane for preventing collision of a load with a seacraft being loaded in rough weather in which one end of a follow-up rope is secured to the seacraft and the rope is reeved around blocks mounted on the boom with the other end being connected to a winch drum for changing the length of the rope to suit the changing distance between the crane and the seacraft. A load supporting rope is reeved around other blocks on the boom and blocks on a crosspiece connected with a mechanism for simultaneously tensioning of both ropes to compensate for changes in distance between the crane and seacraft. Such mechanism includes a two-arm lever mounted in the frame with one arm being connected to the crosspiece and the other arm articulated to a power cylinder-piston unit on the crane serving to turn the lever with a force required to prevent collision of the load with the seacraft.

Description

Lakiza et a1.

[ May 16, 1972 [54] CRANE DEVICE FOR PREVENTING COLLISION OF LOAD WITH SEACRAFT IN ROUGH WEATHER [72] Inventors: Rostislav Ivanovich Lakiza, ulitsa Tolstogo, 20, kv. 14; Petr Ivanovich Soloviev, ulitsa Batumskaya, 13; Vasily Maximovich Dukov, ulitsa Nadezhdy Ostrovskoi. l5, kv. 49; Grigory Rakhmielevich Baron, ulitsa Partizanskaya, 5, kv. 11, all of Sevastopol, USSR.

[22] Filed: Apr. 7, 1970 [21] Appl. No.: 26,319

[52] U.S.CI ..254/l72,212/3,2l4/14 [51] Int. Cl ..B66d 1/50 [58] Field ofSearch ..254/172,173, 189; 214/14;

[56] References Cited UNITED STATES PATENTS 3,591,022 7/1971 Polyakov et a1 ..214/14 X 3,309,065 3/1967 Prudhomme et al ..254/172 3,486,635 12/1969 Thomson ..212/3 X 3,276,746 10/1966 Berne ..254/172 FOREIGN PATENTS OR APPLICATIONS 171,752 11/1965 U.S.S.R. ..214/14 Primary Examiner-Joseph Wegbreit Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Holman & Stern [5 7] ABSTRACT A device mounted on a crane particularly a floating crane for preventing collision of a load with a seacraft being loaded in rough weather in which one end of a follow-up rope is secured to the seacraft and the rope is reeved around blocks mounted on the boom with the other end being connected to a winch drum for changing the length of the rope to suit the changing distance between the crane and the seacraft. A load supporting rope is reeved around other blocks on the boom and blocks on a crosspiece connected with a mechanism for simultaneously tensioning of both ropes to compensate for changes in distance between the crane and seacraft. Such mechanism includes a two-arm lever mounted in the frame with one arm being connected to the crosspiece and the other arm articulated to a power cylinder-piston unit on the crane serving to turn the lever with a force required to prevent collision of the load with the seacraft.

2 Claims, 1 Drawing Figure CRANE DEVICE FOR PREVENTING COLLISION OF LOAD WITH SEACRAFT IN ROUGH WEATHER BACKGROUND OF THE INVENTION The present invention relates to cranes and more specifically to a crane device for preventing collision of a load with a seacraft in rough weather.

The present device can be used most successfully in floating cranes.

Known in the art are similar devices for floating cranes comprising a movable platform-counterweight accommodated in a vertical trunkway. The platform mounts a cargo winch and a winch with a follow-up rope, the second end of which is secured to the seacraft and is reeved around blocks installed on the crane boom and on the vertical trunkway in which the platform-counterweight moves up and down. The load rope running from the cargo winch to the load is reeved around the blocks also mounted on the boom and trunkway (see, for example, Authors Certificate of the USSR No. 219410, Cl. 654,, 26, 1968).

Collision of the load with the seacraft in rough weather is prevented by the platform which moves and simultaneously displaces the load rope with the load. Thus, when the seacraft is lifted on a wave with relation to the crane, the follow-up rope will lower the platform and the load will rise to a height exactly equal to the height of seacrafts lifting movement. Conversely, if the seacraft goes down relative to the floating crane, the follow-up rope will lift the platform and the load will go down a distance equal to the lowered distance of the seacraft.

The known devices of this type are unreliable because probable breaking of the follow-up rope results in the fall of the platform-counterweight which destroys the crane base. Also, there is no guarantee against jamming of the platformcounterweight in the trunkway while the crane is rolling in a heavy swell. The power supply and operation of the winches installed on the platform-counterweight are inconvenient. Handling of loads with different weights is extremely difiicult in view of the constant mass of the counterweight. When the trunkway is tilting on a heeling crane, the vertical component of the counterweight diminishes. Operation of these devices is accompanied by noise produced by the platform-counterweight moving in the trunkway. In addition, changes in the center of gravity of the floating crane caused by the movement of the counterweight may impair stability of the crane, and this factor is particularly important in floating cranes intended for use in rough weather, because the trunkway is relatively high.

Known in the art are other devices of the same application on floating cranes, comprising a cargo winch and a winch with a follow-up rope, the second end of which is secured to the seacraft, with the rope running around blocks installed on the crane boom and those mounted on a movable crosspiece, and the latter is connected to a spring shock absorber. The load rope running from the cargo winch to the load is reeved around the blocks also installed on the crane boom and on the crosspiece (see, for example, Authors Certificate of the USSR No. 151941, C]. 65:1 26,1962).

Collision of the load with the seacraft in rough weather is prevented by changing the distance between the boom blocks and the crosspiece. If the seacraft rises relative to the crane, the follow-up rope becomes slack, the shock absorber springs are stretched, the distance between the boom blocks and the movable cross-piece increases and the load rises the same distance as that of the seacraft. When the seacraft descends relative to the crane, the follow-up rope is tensioned, compressing the shock absorber springs. The distance between the boom blocks and the movable crosspiece becomes smaller and the load descends through a distance equal to the descent of the seacraft. This device can be used only in light swells in view of the limited length of the spring shock absorber.

An object of the present invention resides in eliminating the aforesaid disadvantages.

SUMMARY OF THE INVENTION The main object of the invention lies in providing a crane device for preventing collision of the load with the seacraft in rough weather which, being relatively simple in design, ensures a relatively long travel of the movable crosspiece and excludes the utilization of the energy of a counterweight or compressed spring.

This is accomplished by providing a crane device for preventing collision of the load with the seacraft in rough weather comprises a follow-up rope reeved around the blocks mounted on the crane boom; one end of the follow-up rope is secured to the seacraft while its other end is connected to the crane-mounted winch drum for changing the length of the rope to suit the distance between the crane and the seacraft; a load rope runs around other blocks installed on the boom; both ropes, run around the blocks installed on the crosspiece which is connected to a mechanism for a simultaneous tensioning of both ropes when the distance between the load and the seacraft changes. This mechanism comprises a two-arm lever mounted on the crane, with one arm of the lever being connected to the crosspiece while the other arm is articulated to a power cylinder piston unit installed on the crane and designed to turn or pivot the two-arm lever with a force required for preventing collision of the load with the seacraft in rough weather.

Such device ensures its reliability and convenience in operation.

In the preferable embodiment of the device, according to the invention, it is practicable that the power cylinder piston unit be hydraulic, and its space cylinder communicating with a liquid-filled chamber of a compressed-gas accumulator. This allows the utilization of compressed gas energy which is most convenient in operation.

To prevent collision of the load with the seacraft in rough weather, the two-arm lever has arms of different length, the longer arm being connected with the crosspiece while the shorter arm is articulated to the power cylinder piston unit. Such a design of the device allows the crosspiece to have a relatively large travel.

A substantial advantage of the present invention lies in that it ensures reliable operation of the crane under the conditions of relative vertical displacement of the crane and seacraft in any weather conditions allowable for floating cranes.

Further objects and advantages of the invention will become more readily apparent to persons skilled in the art from the following detailed description and annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The sole FIGURE is a diagrammatic view of a crane device embodying the present invention.

DETAILED DESCRIPTION OF THE INVENTION The device for use in a floating crane 1 for preventing collision of a load 2 with a seacraft 3 in rough weather comprises a follow-up rope 4 running around a block 5 mounted on a transverse member 6a and blocks 5a on a second transverse member 6b of boom 6 of the crane 1. One end of the follow-up rope 4 is secured to the seacraft 3 in a suitable and convenient manner while its other end is connected to the drum of a winch 7 installed on the crane l and intended for changing the length of the follow-up rope 4 secured to the seacraft 3 to suit the distance between the seacraft 3 and the crane 1. The winch 7 is provided with an arrester 8. Running over a block 9 installed on the transverse member 6a of the crane l is a load rope 10 and one end thereof carries the load 2. The other end of the load rope 10 runs over blocks 9a on the transverse member 61: and is connected to the drum of a cargo winch 11 installed on the crane 1. The follow-up rope 4 and the load rope 10 are reeved around blocks 12 and 12a respectively installed on a crosspiece 13 which is connected with a longer arm 14a of a lever 14 having arms of different lengths with shorter arm 14b thereof being articulated to a rod 15 of a piston 16 of a power cylinder 17, mounted on the crane l. The longer arm 14a is provided with horizontally extending pivots 140 to allow the lever 14 to turn or pivot relative to the crane.

The maximum pressure value in the system is determined in accordance with the particular size of the maximum weight (with some excess) for which the crane has been designed to elevate. Hence, the device is capable of lifting a maximum weight and loads of lesser weight without the necessity for an intermediate adjustment of the pressure in the system. The working space of the power cylinder communicates via hollow axle or shaft 18 with a liquid-filled space of a compressed-gas accumulator 19. The lever 14 connected with the power cylinder 17, the cylinder 17 and the compressed-gas accumulator 19 communicating with the cylinder constitute a mechanism for a simultaneous tensioning of both ropes 4 and 10 in case of changes in the distance between the rope 4 and the seacraft 3. The power cylinder 17 serves for turning the lever 14 about its horizontal pivots to the crane with a force required for preventing collision of the load 2 with the seacraft 3 in rough weather.

Before placing the device in operation, the follow-up rope 4 is secured to the seacraft 3 serviced by the crane l The slack of the rope 4 is paid up with the aid of the drum of the winch 7, and the drum is subsequently locked by the arrester 8.

In rough weather, when the seacraft 3 descends vertically relative to the crane l, the follow-up rope 4 is tensioned and actuates the rod 15 of the hydraulic cylinder 17 via the (unequal-arm) lever 14. The operating fluid is forced out of the cylinder 17 by the piston 16 through the hollow axle 18 into the liquid-filled space of the compressed-gas accumulator 19, and compresses the gas in the latter. The turning of the (twoarm) lever 14 reduces the distance between the crosspiece 13 and the blocks 5, a of the boom 6. Hence, the load rope is paid out and the load is correspondingly lowered a distance equal to the lowering of the seacraft 3 with relation to the crane 1.

When the seacraft 3 rises relative to the crane 1, the followup rope 4 becomes slack. The gas compressed in the accumulator l9 expands and forces the operating fluid from the accumulator into the hydraulic cylinder 17 and piston 16 thereof transmits the force to the load 2 via the rod 15, the (two-arm swivelling) lever 14, the blocks 12 and the load rope 10. By

virtue of being acted upon by this force, the load 2 rises to a height equal to the ascent of the seacraft with relation to the crane 1.

The follow-up rope 4 arranged between the boom 6 and the seacraft 3 has a double mechanical advantage over the respective lines of the load rope 10. This double advantage is compensated by according double advantage of the load rope speed of movement over that of the follow-up rope 4 at the portion thereof between the crosspiece 13 and the boom 6.

The device described above makes it possible to utilize the energy of compressed air which is convenient in operation and excludes the effect of rolling on the functioning of the device. The (unequal-arm) lever having arms of different length allows the crosspiece to be displaced over comparatively long distances, thus making it possible to handle the loads in very rough weather.

What is claimed is:

1. A device mounted on a crane for preventing collision of a load with a seacraft being loaded in rough weather, comprising a boom for the crane; a winch having a drum positioned on the crane; blocks mounted on the boom, a follow-up rope running around said blocks and having one end secured to the seacraft; the other end of said follow-up rope being connected to the drum of the winch for changing the length of said follow-up rope to suit the distance between said crane and the seacraft; a load supporting rope; a crosspiece provided with blocks mounted thereon and supporting said follow-up and load ropes; a mechanism for simultaneous tensioning of said load and follow-up ropes during changes in the distance between said crane and seacraft, said mechanism including a lever having arms of different length, said lever being pivotally mounted on said crane; a power cylinder-piston unit mounted on said crane; the longer arm of said lever being connected with said crosspiece and means articulating the shorter arm to the power cylinder-piston unit for simultaneous turning of said lever with a force required for preventing collision of the load with said seacraft. I

2. The device according to claim 1, including a compressed gas accumulator and said power cylinder-piston unit being hydraulic and its cylinder space being in communication with the fluid-filled space of the compressed gas accumulator.

Claims (2)

1. A device mounted on a crane for preventing collision of a load with a seacraft being loaded in rough weather, comprising a boom for the crane; a winch having a drum positioned on the crane; blocks mounted on the boom, a follow-up rope running around said blocks and having one end secured to the seacraft; the other end of said follow-up rope being connected to the drum of the winch for changing the length of said follow-up rope to suit the distance between said crane and the seacraft; a load supporting rope; a crosspiece provided with blocks mounted thereon and supporting said follow-up and load ropes; a mechanism for simultaneous tensioning of said load and follow-up ropes during changes in the distance between said crane and seacraft, said mechanism including a lever having arms of different length, said lever being pivotally mounted on said crane; a power cylinder-piston unit mounted on said crane; the longer arm of said lever being connected with said crosspiece and means articulating the shorter arm to the power cylinder-piston unit for simultaneous turning of said lever with a force required for preventing collision of the load with said seacraft.

2. The device according to claim 1, including a compressed gas accumulator and said power cylinder-piston unit being hydraulic and its cylinder space being in communication with the fluid-filled space of the compressed gas accumulator.

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