Apparatus for limiting chain wear

A trenching machine comprising:

• a trenching boom;
• and
• a chain assembly supported by said trenching boom, said chain assembly comprising:
• a plurality of links where each link includes first and second substantially parallel spaced-apart sidebars, each sidebar having a forward sidebar end and a rearward sidebar end separated from each other by the length of the sidebar, an upper sidebar edge and a lower sidebar edge separated from each other by the height of the sidebar, an outer sidebar surface and an inner sidebar surface separated from each other by the thickness of the sidebar, wherein the inner sidebar surfaces of each pair of sidebars face each other and the outer sidebar surfaces of each pair of sidebars face outwardly of the pair of sidebars, a forward sidebar aperture located adjacent the forward sidebar end and passing from the outer sidebar surface to the inner sidebar surface and a rearward sidebar aperture adjacent the rearward sidebar end and passing from the outer sidebar surface to the inner sidebar surface, each link of said chain further including a forward chain pin having a pin head and a shaft passing through the forward sidebar apertures of the first and second sidebars so that the pin head of the forward chain is adjacent the outer sidebar surface of the first sidebar, said chain further including a rearward chain pin having a pin head and a shaft passing through the rearward sidebar apertures of the first and second sidebars so that the pin head of the rearward chain pin is adjacent the outer sidebar surface of the first sidebar, the apparatus comprising:
• a wear bar for attachment to the outer sidebar surface of the first sidebar of at least one of the links of the chain for limiting wear to one or more chain pin heads and at least the lower sidebar edge of the first sidebar, said wear bar including a main body portion having:
• a forward wear bar end;
• a rearward wear bar end spaced from the forward wear bar end by the length of the wear bar;
• an inner wear bar surface for placement adjacent the outer sidebar surface of the first sidebar;
• an outer wear bar surface spaced from the inner wear bar surface by the thickness of the wear bar;
• an upper wear bar edge;
• a lower wear bar edge spaced from the upper wear bar edge by the height of the wear bar and positioned closely adjacent the lower sidebar edge to limit wear to the lower sidebar edge;
• and
• at least one opening dimensioned to receive at least part of one of the pin heads so that the portion of the wear bar adjacent the opening limits contact between the pin head and adjacent material being cut;
• wherein the thickness of the wear bar between the inner and outer wear bar surfaces is at least as great as the thickness of the pin heads of the forward and rearward chain pins.

A method for limiting wear in a chain having a plurality of links where each link includes first and second substantially parallel spaced-apart sidebars, each sidebar having a forward sidebar end and a rearward sidebar end separated from each other by the length of the sidebar, an upper sidebar edge and a lower sidebar edge separated from each other by the height of the sidebar, an outer sidebar surface and an inner sidebar surface separated from each other by the thickness of the sidebar, wherein the inner sidebar surfaces of each pair of sidebars face each other and the outer sidebar surfaces of each pair of sidebars face outwardly of the pair of sidebars, a forward sidebar aperture located adjacent the forward sidebar end and passing from the outer sidebar surface to the inner sidebar surface and a rearward sidebar aperture adjacent the rearward sidebar end and passing from the outer sidebar surface to the inner sidebar surface, each link of said chain further including a forward chain pin having a pin head and a shaft passing through the forward sidebar apertures of the first and second sidebars so that the pin head of the forward chain is adjacent the outer sidebar surface of the first sidebar, said chain further including a rearward chain pin having a pin head and a shaft passing through the rearward sidebar apertures of the first and second sidebars so that the pin head of the rearward chain pin is adjacent the outer sidebar surface of the first sidebar, the method comprising:

• attaching a wear bar to the outer surface of the first sidebar to limit wear to the forward and rearward chain pin heads and to limit wear to the lower sidebar edge of the first sidebar, said wear bar having a forward wear bar end and a rearward wear bar end spaced from the forward wear bar end by the length of the wear bar, an inner wear bar surface adjacent the outer sidebar surface of the first sidebar, an outer wear bar surface spaced from the inner wear bar surface by the thickness of the wear bar, wherein the thickness of the wear bar between the inner and outer wear bar surfaces is at least as great as the thickness of the pin heads of the forward and rearward chain pins, an upper wear bar edge, a lower wear bar edge spaced from the upper wear bar edge by the height of the wear bar and positioned closely adjacent the lower sidebar edge to limit wear to the lower sidebar edge, and at least one opening dimensioned to receive at least part of one of the pin heads so that the portion of the wear bar adjacent the opening limits contact between the pin head and adjacent material being cut.

An apparatus for limiting chain wear in a chain having a plurality of links where each link includes first and second substantially parallel spaced-apart sidebars, each sidebar having a forward sidebar end and a rearward sidebar end separated from each other by the length of the sidebar, an upper sidebar edge and a lower sidebar edge separated from each other by the height of the sidebar, an outer sidebar surface and an inner sidebar surface separated from each other by the thickness of the sidebar, wherein the inner sidebar surfaces of each pair of sidebars face each other and the outer sidebar surfaces of each pair of sidebars face outwardly of the pair of sidebars, a forward sidebar aperture located adjacent the forward sidebar end and passing from the outer sidebar surface to the inner sidebar surface and a rearward sidebar aperture adjacent the rearward sidebar end and passing from the outer sidebar surface to the inner sidebar surface, each link of said chain further including a forward chain pin having a pin head and a shaft passing through the forward sidebar apertures of the first and second sidebars so that the pin head of the forward chain is adjacent the outer sidebar surface of the first sidebar, said chain further including a rearward chain pin having a pin head and a shaft passing through the rearward sidebar apertures of the first and second sidebars so that the pin head of the rearward chain pin is adjacent the outer sidebar surface of the first sidebar, the apparatus comprising:

• a wear bar for attachment to the outer sidebar surface of the first sidebar of at least one of the links of the chain for limiting wear to one or more chain pin heads and at least the lower sidebar edge of the first sidebar, said wear bar including a main body portion having:
• a forward wear bar end;
• a rearward wear bar end spaced from the forward wear bar end by the length of the wear bar;
• an inner wear bar surface for placement adjacent the outer sidebar surface of the first sidebar;
• an outer wear bar surface spaced from the inner wear bar surface by the thickness of the wear bar;
• an upper wear bar edge;
• a lower wear bar edge spaced from the upper wear bar edge by the height of the wear bar and positioned closely adjacent the lower sidebar edge to limit wear to the lower sidebar edge;
• at least one opening dimensioned to receive at least part of one of the pin heads so that the portion of the wear bar adjacent the opening limits contact between the pin head and adjacent material being cut;
• wherein the thickness of the wear bar between the inner and outer wear bar surfaces is at least as great as the thickness of the pin heads of the forward and rearward chain pins;
• and
• means attaching the wear bar to the first sidebar.