Abstract:
Lubrication devices for lubricating wire rope on a crane. Spray nozzles may be permanently mounted to the multi-sheaved wire block assemblies. A controller and oil supply located near the base of the crane are used to control and deliver oil to the spray nozzles. A telescopic spray unit is used to lubricate the vertical stationary wire rope. A crawler that rides on the wire rope is used to lubricate the stationary wire rope between the anchor point and the first sheave of the block assembly. Improved clamshell units are used to lubricate the wire rope between the drums storing wire rope and the first sheave.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is generally related to the lubrication of wire ropes and more particularly to the in situ lubrication of wire ropes on cranes. 
     2. General Background 
     Wire rope is a flexible, tough, complex, and versatile mechanical power transmission member made up of numerous individual wires. During normal operation these wires are subject to torsion, bending, tension, and compression stresses. To achieve maximum performance and life, lubrication of the wire rope structure must be maintained so that coordinated sliding action between individual wires permits most favorable distribution of these stresses. Good lubrication offers protection against corrosion and minimizes metal-to-metal contact between individual wires while reducing wear on the rope and on the drum and sheaves over which it operates. 
     Wire rope used on cranes typically is pre-lubed by the manufacturer with a base lubricant. Typically, this is a thick lubricant with very high viscosity (10 to 30,000 SUS) that provides good protection during storage. However, to perform properly, a wire rope must also be field lubricated periodically. For this post-lube application a lighter viscosity oil such as 150 SUS must be applied to the rope because, during operation, tensions in the rope and pressure encountered while operating over sheaves and drums all work toward forcing the original lubricant to the rope surface. New oil is needed to counteract that action. 
     Field lubrication of wire rope has traditionally been done by one or more methods. A stationary device may be positioned such that it surrounds the wire rope in a continuous bath and lubricates the rope as it moves through the device. Lubricant may be dripped or poured on the wire rope and the excess then wiped off. Lubricant may be swabbed or painted on the wire rope. Some of these operations must be done manually. 
     The nature of large cranes, especially those used on derrick barges for offshore work, precludes the use of most of the current lubrication methods for several reasons. Large cranes have miles of wire rope, some of which moves in excess of one hundred feet per minute. Cranes achieve a mechanical advantage by the use of multi-sheaved wire rope block assemblies. This creates numerous closely spaced wire loops, which make in-situ lubrication very difficult. Conventional wire rope lubricators are not well suited to address a plurality of closely spaced wires due to the large size of the lubricators and their inability to operate in hands-off mode (they require constant attention and adjustment). Current lubrication devices are not designed for a plurality of wire ropes like the ones present in a multi-sheaved wire rope assembly. Current lubrication devices can not be installed and maintained in inaccessible locations like the boom of a derrick crane or the main block of a multi-sheaved hoist. Current lubrication devices are typically stationary but rely on relative motion between wire and lubricator. One such device is the pressurized clamshell lubricator. Pressurized clamshell lubricators have a split-housing chamber with round openings in their axial direction. The wire rope is fed through the axial openings and bathed in lubricant. Current clamshell units have disadvantages. They require a lot of time to set up and take down. Also, they must be removed during normal crane operation. Bathing the wire rope in lubricant tends to use excess lubricant that is not required. This wastes lubricant and causes pollution problems. In a crane, portions of the wire rope are stationary once installed. Thus, a stationary lubrication device is ineffective for those portions of wire rope. 
     It can be seen that the current state of the art does not address all needs in lubricating wire rope on cranes. 
     SUMMARY OF THE INVENTION 
     The invention allows for lubrication of the entire length of wire rope in a crane after wire is installed. This is done with the various devices that are described herein. Spray nozzles may be permanently mounted to the multi-sheaved wire block assemblies. A controller and oil supply located near the base of the crane are used to control and deliver oil to the spray nozzles. A telescopic spray unit is used to lubricate the vertical stationary wire rope. A crawler that rides on the wire rope is used to lubricate the stationary wire rope between the anchor point and the first sheave of the block assembly. Improved clamshell units are used to lubricate the wire rope between the drums storing wire rope and the first sheave. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature and objects of the present invention reference should be made to the following description, taken in conjunction with the accompanying drawings in which like parts are given like reference numerals, and wherein: 
     FIG. 1 is an elevation view of a crane on a barge. 
     FIG. 2 illustrates a spray nozzle mounted on a sheave block. 
     FIG. 3 is an enlarged view of FIG.  2 . 
     FIG. 4 is a schematic illustration of the spray nozzle arrangement. 
     FIG. 5 is an elevation view of a manual lubricating device. 
     FIG. 6 is a top view of the device of FIG.  5 . 
     FIG. 7 is a plan view of a crawler lubrication device. 
     FIG. 8 is an end view of the crawler device being installed on a wire rope. 
     FIG. 9 is an end view of the crawler device installed on a wire rope. 
     FIG. 10 is an elevation view of an improved clamshell lubricating device. 
     FIG. 11 is a top view of the device shown in FIG.  10 . 
     FIG. 12 is a cutaway view of the clamshell device of FIG.  10 . 
     FIG. 13 is an enlarged view of the area indicated in FIG.  12 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, FIG. 1 indicates a typical crane  10  on a barge  12 . Wire spools  14  hold a supply of wire rope  16  that is threaded around a series of pulleys  18 , a boom sheave block  20 , and a hoist sheave block  22 . The sheave blocks typically are multi-sheave units that require multiple wraps of the wire rope. 
     A wire rope lubrication apparatus provided for the wire rope at the sheave blocks is generally comprised of spray nozzles  24 , a controller  26 , an oil supply  28 , an air/oil line  30 , and flow control means  32 . 
     FIG. 4 schematically illustrates the apparatus. A pump  34  directs oil from the oil supply  28  into the oil line  30   a.  A compressed air source  36  supplies compressed air to the air line  30   b  through air filter  38 . Flow controls  32  are comprised of a liquid pressure regulator  40 , oil filter  42 , shut-off valves  44 , air pressure regulators  46 , and solenoid valves  48 . Shut-off valves  44  are used to block the flow of fluids during preventive maintenance operations. Solenoid valves  48  activate the spray nozzle arrangement to spray lubricant on the wire rope through the nozzles  24 . 
     FIGS. 2 and 3 illustrate the mounting of the spray nozzle  24  on a sheave block  20  and a detail view of the spray nozzle arrangement. An atomizing nozzle  50  is housed in a bracket  52  mounted on the sheave block  20 . Low pressure air from line  54  is used to atomize lubricant delivered through lubricant line  56 . A high pressure air line  58  is used to activate a piston (not shown) in a cylinder that cleans the orifice of the atomizing nozzle  50 . Although only one spray nozzle arrangement is shown and described, it should be understood that a plurality of spray nozzle arrangements may be provided to accommodate all wraps of the wire rope  16  around the multiple sheaves of the block. 
     In operation, an operator uses the controller  26  as necessary to direct lubricant to the wire rope on the sheave blocks. 
     FIGS. 5 and 6 illustrate a manual wire rope lubricating device  60  that is particularly suitable for lubricating the vertical stationary wire ropes  62  (at the anchor point of a block) that can not be lubricated by in-line lubrication devices. Lubricating device  60  is comprised of an atomizing nozzle  50  mounted in a body  64 . Body  64  is provided with a plurality of concave wheels  66  either rotatably mounted therein or locked to function as skids. Wheels  66  are sized to be received on the stationary wire rope  62  to provide guidance and keep the nozzle  50  at the proper attitude and location. One end of the body  64  is provided with a hinged, spring loaded shroud  68  to provide for ease of placing on the wire rope  62 . A telescoping handle  70  is pivotally attached at  72  as illustrated. Oil and air are supplied to the nozzle  50  via line  74 . Oil and air can be supplied with a pressurized canister not shown having both fluids. Alternatively, air can be supplied with a conventional compressor and oil supplied by a positive displacement pump. Fluid pressure regulators will be mounted near the source. An operator opens the hinged shroud  68 , places the wheels  66  against the wire rope  62 , closes the shroud  68 , turns on the air and oil supply and then uses the handle to move the device along the length of wire rope  62 . The oil discharge from the nozzle lubricates the wire rope. The shroud  68  captures excess oil and swirls the atomized oil around the wire rope  62 . 
     A portion of the wire rope that is used by cranes with multi-sheaved block assemblies never moves in relation to the sheaves or the rest of the structure. This section comprises the wire rope that is located between the anchor point and the first sheave of the block assembly. This section of wire rope is indicated by numeral  76  in FIG.  1 . FIG. 7 illustrates a crawler lubricating device  78  particularly suited to this section of wire rope. 
     As seen in FIGS. 7-9 the crawler lubricating device  78  is generally comprised of a body formed from two halves  80   a,b,  a plurality of wheels  82  either rotatably mounted or locked as skids in the body, and atomizing spray nozzles  84 . The two body halves  80   a,b  are attached together by a hinge  86  to allow for quick installation over a wire rope  76 . Once the crawler is placed over the wire rope  76 , the body is locked over the wire rope with a locking pin  88  to prevent the crawler from falling during the lubrication phase. 
     The wheels  82  are concave and sized to receive the wire rope  76  to be lubricated. The wheels  82 , as shaped, will roll or skid on the wire rope  76  regardless of orientation with respect to gravity. 
     The atomizing spray nozzles  84  are similar to those described above in that both air and oil are used simultaneously to create a pressurized fog of lubricant fluid. The nozzles  84  are mounted and positioned on the body  80   a,b  so as to direct the atomized oil toward the wire rope  76  as the crawler moves along the wire rope. An air line  90  and oil line  92  are mounted on the body  80   a,b  and in fluid communication with the nozzles  84 . The air and oil lines are in communication with an air supply and oil supply not shown. An air pressure regulator  94  and oil pressure regulator  96  are mounted on the body  80   a,b  for adjusting the atomized spray as necessary. By mounting here, the fluid pressures are automatically compensated for changes in elevation, assuring constant fluid flow. 
     A shroud  98  may be provided to capture excess oil and to swirl the atomized oil around the wire rope  76 . The shroud is formed from two portions attached to each body portion  80   a,b.    
     The crawler  78  can be pulled with a flexible cable attached to an air tugger or it can be pulled manually by an operator located on the opposite end of the multi-sheaved block assembly. 
     FIGS. 10-13 illustrate an improved clamshell lubricating device  100  that is generally comprised of a body formed from two halves  102   a,b  and atomizing spray nozzles  104 . 
     The two body halves  102   a,b  are attached together by a hinge  106  to allow for quick installation over a wire rope  16 . The body halves are held in the closed position over the wire rope by bolts or screws  108  threaded through flanges on the body halves. The body  102  is open at each end to allow passage of the wire rope  16  therethrough. 
     A plurality of atomizing spray nozzles  104  are mounted in the body  102  and positioned to direct the atomized oil toward the wire rope  16 . As described above, each nozzle  104  has a high pressure air line  110 , a low pressure air line  112 , and an oil line  114 . The high pressure air line is used to activate a piston not shown that cleans the orifice in the nozzle. The low pressure air and oil lines are used to supply air and oil pressure from sources not shown to spray atomized oil on the wire rope. 
     One or more air jets  116  may be formed in the body  102  to blow debris off the wire rope  16  before it is lubricated. High pressure air is supplied through intake ports  117 , which are in communication with a source not shown. An O-ring may be provided at the inner portion of the body  102  around the intake ports  117  if necessary to provide the proper seal. An exhaust manifold  118  may be provided and connected to a vacuum source not shown for removing the debris loosened by the air jet  116 . The exhaust manifold  118  is connected to ports  120  provided on the body  102 . 
     A seal  126  may be provided at each end of the body  102  and between the cleaning section and the lubrication section. The seals  126  are preferably formed from a compliant material such as rubber or a cylindrical brush. The seals serve to minimize the amount of debris that enters the body  102  and the amount of excess lubrication fluid that escapes the lubrication section. 
     Chain or cable  122  is used to secure the clamshell device  100  to a stationary structure  124 . The lateral flexibility provided by the chain or cable is necessary if the device is mounted near the spool that stores and pays out the wire rope. 
     Because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.