Mast head for a dragline

Abstract

A mast head assembly for a dragline comprises an elongated body for connecting to a mast of a dragline. The elongated body includes side plates on opposite sides of the body. The side plates have suspension lugs and chord and lacing stubs for attaching cables from the mast head to the boom of a dragline. At least one of the cord stubs is located above and to the rear of a first chord stub. The chord and lacing stubs are positioned on the side plates so that the maximum stress in the mast head assembly is where the chord stub connects to the original chord. The highest remaining stress is located at the point where the upper/rear chord stub connects to the original chord.

1 . A mast head assembly for a dragline comprising:
 an elongated body for connecting to a mast of a dragline;   said body having opposing side plates and chord and lacing stubs;   said side plates having suspension lugs for attaching cables from the mast head to the boom of a dragline;   said lacing stubs positioned on said side plates to provide structural stability;   at least one of said chord stubs located above and to the rear of a first chord stub;   wherein the highest remaining stress is located at the point where the upper/rear chord stub connects to the original chord.   
     
     
         2 . A mast head for a dragline comprising:
 an elongated body configured to connect to a mast of the dragline, the mast having at least one chord member and at least one lacing member;   the body having opposing side plates, a top plate and a bottom plate,   a suspension lug extending from each side plate and configured to receive cables supporting a boom of the dragline;   a lacing stub disposed on at least one of the side plates and configured to connect with the lacing member; and   at least one chord stub disposed on the bottom plate and configured to connect with the chord member.   
     
     
         3 . The mast head of  claim 2 , wherein the side plates are substantially parallel to one another, and the suspension lugs extend from the side plates in a substantially coplanar manner. 
     
     
         4 . The mast head of  claim 3 , wherein the suspension lugs are integral extensions of the side plates. 
     
     
         5 . The mast head of  claim 3 , wherein the suspension lugs each include an opening, and the openings are substantially axially aligned with one another. 
     
     
         6 . The mast head of  claim 2 , wherein each of the side plates include an angled portion that converge toward one another proximate the bottom plate to form a tapered region of the mast head. 
     
     
         7 . The mast head of  claim 6 , wherein the lacing stub is disposed on one of the angled portions. 
     
     
         8 . The mast head of  claim 7 , wherein the at least one chord member comprises a first chord member and a second chord member, and the at least one chord stub comprises a first chord stub and a second chord stub disposed on the bottom plate, and wherein the first chord stub is configured to connect with the first chord member and the second chord stub is configured to connect with the second chord member. 
     
     
         9 . The mast head of  claim 8 , wherein the at least one chord member further comprises a third chord member and a fourth chord member, and further comprising a second mast head having:
 an elongated body having opposing side plates, a top plate and a bottom plate, the side plates each having an angled portion that converge toward one another proximate the bottom plate,   a suspension lug extending from each side plate and configured to receive cables supporting a boom of the dragline;   a lacing stub disposed on one of the angled portions and configured to connect with another lacing member; and   a third chord stub disposed on the bottom plate and configured to connect with the third chord member, and a fourth chord stub disposed on the bottom plate and configured to connect with the fourth chord member.   
     
     
         10 . The mast head of  claim 2 , wherein the lacing member and the chord member each have a longitudinal axis configured to intersect with one another at an intersection location, and wherein the elongated body substantially envelops the intersection location. 
     
     
         11 . The mast head of  claim 2 , wherein each side wall further comprises a hub formed therein, each hub being substantially free of support gussets. 
     
     
         12 . A dragline for mining, comprising:
 a boom;   a mast having at least one chord member and at least one lacing member; and   at least one mast head, comprising:
 an elongated body connected to the mast and having opposing side plates, a top plate and a bottom plate; 
 a suspension lug extending from each side plate and configured to receive cables supporting the boom; 
 a lacing stub disposed on at least one of the side plates and configured to connect with the lacing member; and 
 at least one chord stub disposed on the bottom plate and configured to connect with the chord member. 
   
     
     
         13 . The mast head assembly of  claim 1 , wherein the side plates are substantially parallel to one another, and the suspension lugs extend from the side plates in a substantially coplanar manner. 
     
     
         14 . The mast head assembly of  claim 13 , wherein the suspension lugs are integral extensions of the side plates. 
     
     
         15 . The mast head assembly of  claim 13 , wherein the suspension lugs each include an opening, and the openings are substantially axially aligned with one another. 
     
     
         16 . The mast head assembly of  claim 1 , wherein each of the side plates include an angled portion that converge toward one another to form a tapered region of the mast head assembly, and wherein the lacing stub is disposed on one of the angled portions. 
     
     
         17 . The mast head assembly of  claim 1 , wherein the mast includes one or more chord members and one or more lacing members, wherein at least one of the lacing stubs is configured to connect with at least one of the lacing members and the upper rear chord stub is configured to connect with at least one of the chord members. 
     
     
         18 . The mast head assembly of  claim 17 , wherein the mast includes a first chord member and a second chord member, and the at least one chord stub comprises a first chord stub and a second chord stub disposed on the bottom plate, and wherein the first chord stub is configured to connect with the first chord member and the second chord stub is configured to connect with the second chord member. 
     
     
         19 . The mast head assembly of  claim 17 , wherein the lacing members and the chord members each have a longitudinal axis configured to intersect with one another at an intersection location, and wherein the elongated body substantially envelops the intersection location. 
     
     
         20 . The mast head assembly of  claim 1 , wherein each side wall further comprises a hub formed therein, each hub being substantially free of support gussets.