Digging tooth and teeth arrayed in combination with endless excavating chain

A metallic digger tooth comprising:

• a L-shaped metal plate which includes a shank portion and a toe portion extending from an edge of the shank portion and generally forming an angle of from about 60.degree. to about 120.degree. with the shank portion, said metal plate having an L-shaped leading edge extending along the shank portion and along the toe portion, said leading edge having a sharpened cutting portion extending along said toe portion;
• and
• a first rectangular band of hard-facing positioned adjacent, and having one edge colinear and coextensive with, the portion of said leading edge extending along the toe portion of said plate;
• and
• a second rectangular band of hard-facing extending from one end of said first band along a portion of said L-shaped leading edge which extends along said shank portion wherein said hard facing is selected from the group consisting of titanium carbide, tungsten carbide, and ceramic material.

A trenching chain assembly for use in a trenching machine and comprising:

• an elongated, endless chain having opposite sides and having a lengthwise aspect and a width, and having a centrally disposed longitudinal axis extending along its length between opposite sides of the chain, said chain including a plurality of interconnected, articulated links having spaced, tooth mounting plates each adapted to support a digging tooth, said tooth mounting plates being located on opposite sides of the longitudinal axis of the chain;
• and
• an array of digging teeth secured to, and projecting from the chain, the array of digging teeth including a repeating pattern of six digging teeth spaced along the chain, said six digging teeth including:
• a first L-shaped leading tooth secured to one of said tooth mounting plates on one side of the chain, said first L-shaped leading tooth including:
• a shank portion secured to said one tooth mounting plate;
• and
• a toe portion secured to said shank portion and projecting across the chain toward the side of the chain opposite the side upon which said one tooth mounting plate is located, said toe portion and said shank portion forming an angle of from about 60.degree. to about 120.degree. with each other, and each having a beveled, sharpened, leading cutting edge on a side thereof facing in the direction in which the chain is moving;
• said six digging teeth in the repeating pattern further including:
• a second L-shaped tooth spaced along said chain from said first leading L-shaped tooth in the opposite direction from the direction in which said chain is moved during digging of a trench, said second, L-shaped tooth being secured to a second of said tooth mounting plates located on the opposite side of said chain from said first tooth mounting plate and spaced in an axial direction along the chain from said first tooth mounting plate, said second L-shaped tooth including:
• a shank portion of said second L-shaped tooth secured to said second tooth mounting plate;
• and
• a toe portion of said second L-shaped tooth secured to the shank portion of said second L-shaped tooth and projecting across the chain toward the side of the chain opposite the side upon which said second tooth mounting plate is located, and opposite the direction of projection of the toe portion of said first, leading L-shaped tooth, said toe portion of said second L-shaped tooth and said shank portion of said second L-shaped tooth forming an angle of from about 60.degree. to about 120.degree. with each other, and each of said shank portion and said toe portion of said second L-shaped tooth having a beveled, sharpened, leading cutting edge on a side thereof facing in the direction in which the chain is moving, said second L-shaped tooth having a part of its toe portion positioned behind, and shielded by, a part of the toe portion of said first L-shaped tooth at a location relatively near to the longitudinal axis of the chain whereby said first L-shaped tooth undergoes wear while protecting a portion of the toe portion of the second L-shaped tooth over an extended period of time thereby extending the life of the trenching chain assembly;
• said repeating pattern of six digging teeth further including:
• a third L-shaped tooth spaced axially along said chain from said second L-shaped tooth in a direction away from the direction of movement of said chain during the digging of a trench, and secured to a third of said tooth mounting plates mounted on the opposite side of the chain from said second tooth mounting plate and on the same side of said chain as said first tooth mounting plate, said third L-shaped tooth including:
• a shank portion of said third L-shaped tooth secured to said third tooth mounting plate;
• and
• a toe portion of said third L-shaped tooth secured to the shank portion of said third L-shaped tooth and projecting outwardly from the chain away from the central longitudinal axis of the chain, said toe portion of said third L-shaped tooth and the shank portion of said third L-shaped tooth forming an angle of from about 60.degree. to about 120.degree. with each other, and each having a beveled, sharpened, leading cutting edge on a side thereof facing in the direction in which the chain is moving;
• said repeating pattern of six digging teeth further including:
• a fourth L-shaped digging tooth spaced axially along said chain from said third L-shaped digging tooth in a direction opposite the direction of movement of said chain, said fourth L-shaped digging tooth being secured to a fourth of said tooth-mounting plates on the opposite side of said chain from said third L-shaped digging tooth, and on the same side of said chain as said second tooth-mounting plate, and spaced along the chain in an axial direction from said third tooth-mounting plate, said third L-shaped tooth including:
• a shank portion of said fourth L-shaped cutting tooth secured to said fourth tooth mounting plate;
• and
• a toe portion of said fourth L-shaped cutting tooth secured to the shank portion of said fourth L-shaped cutting tooth and projecting outwardly away from said chain and away from the central longitudinal axis of said chain in a direction opposite the direction of projection of the toe portions of said first and second teeth with respect to the shank portions of said first and second L-shaped teeth, said toe portion of said fourth L-shaped tooth and said shank portion of said fourth L-shaped tooth forming an angle of from about 60.degree. to about 120.degree. with each other, and each having a beveled, sharpened, leading cutting edge on a side thereof facing in the direction in which the chain is moving;
• said repeating pattern of siad six digging teeth further including:
• a cup-shaped fifth cutting tooth spaced along said chain from said fourth L-shaped cutting tooth in a direction away from said fourth L-shaped cutting tooth and opposite the direction in which said chain moves during digging of a trench, said cup-shaped fifth cutting tooth being secured to a fifth one of said tooth mounting plates disposed on the opposite side of said chain from said fourth tooth-mounting plate, and said cup-shaped fifth cutting tooth including:
• a shank portion of said cup-shaped fifth cutting tooth secured to said fifth mounting plate;
• and
• a cup-shaped toe portion of said cup-shaped fifth cutting tooth secured to said shank portion of said cup-shaped fifth cutting tooth, said toe portion being of generally C-shaped cross-sectional configuration, said cup-shaped toe portion being oriented to face the convex outer side thereof away from the axis of the chain, and to face the concave inner side thereof toward the axis of the chain, said cup-shaped toe portion having a beveled, sharpened, leading cutting edge on a side thereof facing in the direction in which said chain is moving, and said cup-shaped fifth tooth terminating in a point positioned behind and shielded by a part of the toe portion of said third L-shaped cutting tooth;
• and
• said repeating pattern of six digging teeth further including:
• a cup-shaped sixth digging tooth secured to a sixth of said tooth mounting plates located on the opposite side of said chain from said fifth tooth-mounting plate and spaced axially along said chain from said fifth tooth-mounting plate and in the opposite direction from the direction of movement of said chain, said cup-shaped sixth digging tooth including:
• a shank portion of said cup-shaped sixth digging tooth secured to said sixth tooth-mounting plate;
• and
• a cup-shaped toe portion projecting from said shank portion of said cup-shaped sixth digging tooth, having a generally C-shaped cross-sectional configuration, and oriented to present the convex side of said toe portion on the outer side of the cup-shaped tooth away from the chain, and to present the concave side of said cup portion facing inwardly toward the axis of said chain, said cup-shaped sixth digging tooth having a beveled, sharpened, leading cutting edge facing in the direction in which said chain is moving;
• said cup-shaped toe portion of said cup-shaped sixth digging tooth terminating in a point positioned behind, and shielded by, a part of the toe portion of said fourth L-shaped tooth whereby the efficiency and effective service life of the trenching chain assembly is extended.

A trenching chain assembly for use in a trenching machine for digging elongated trenches and comprising:

• an elongated, endless chain having opposite sides and having a lengthwise aspect and a width, and having a centrally disposed longitudinal axis extending along its length between opposite sides of the chain, said chain including a plurality of interconnected, articulated links having spaced, tooth-mounting plates each adapted to support a digging tooth, said tooth-mounting plates being located on opposite sides of the longitudinal axis of the chain and generally defining, by their separation, the width of the chain;
• and
• an array of digging teeth secured to, and projecting from, the chain, the array of digging teeth including:
• at least one trench face shearing tooth mounted on the chain and having a toe portion extending generally transversely with respect to the direction of the travel of the chain during the digging of a trench and projecting either inwardly toward the longitudinal axis of the chain, or outwardly away from the longitudinal axis of the chain, said toe portion being spaced from a plane containing the longitudinal axis of the chain;
• and
• means for connecting said toe portion to at least one of said plates of the chain, and for spacing said toe portion from said plane containing the longitudinal axis of the chain, said toe portion including a hard-faced leading cutting edge, with the hard facing thereon including particles selected from the group consisting of titanium carbide, tungsten carbide, and ceramic material;
• and
• at least one cup-shaped gauge tooth mounted on the chain and spaced longitudinally therealong from each of the trench face shearing teeth on the chain so as to follow and track at least one of the trench face shearing teeth, each of said cup-shaped teeth including a curved, convex outer side facing away from the longitudinal axis of the chain and a concave inner side facing toward the longitudinal axis of the chain, said curved, convex outer side being spaced outwardly from a plane containing the longitudinal axis of the chain and adapted for shearing away the side walls of a trench dug by the trenching chain assembly, and thus constituting gauging teeth for gauging the width of the trench;
• and
• means for connecting said cup-shaped tooth to at least one of said plates of the chain.

An endless trenching chain assembly for use on a trenching machine for continuously forming and advancing a trench having a face and a pair of laterally-shaped, substantially parallel side walls, the trenching chain assembly comprising:

• an elongated, endless chain having opposite sides and having a lengthwise aspect and a width, and having a centrally disposed longitudinal axis extending along its length between opposite sides of the chain for extension parallel to the side walls of the trench, said chain further including a plurality of interconnected, articulated links extending successively along the lengthwise aspect of the chain, said links including lateral plates located at opposite sides of the chain, and shaft means interconnecting said lateral plates and defining spaced sprocket tooth-receiving openings along the length of the chain;
• and
• a plurality of generally L-shaped shearing teeth secured at spaced intervals along the chain, said shearing teeth each including:
• a toe portion extending at an angle of about 105.degree. to a plane containing the longitudinal axis of the chain and said plane extending substantially parallel to the vertical side walls of the trench dug by the chain, said toe portion further including a convex outer side, and a concave inner side spaced closer to the chain than the outer side by the amount of the thickness of the toe portion, said toe portion further including a leading, cutting edge beveled to a sharpened edge at one side thereof;
• a shank portion connected to the toe portion and secured to the chain in a position to space the toe portion outwardly from the chain;
• and
• hard-facing on the convex outer side of said toe portion adjacent said leading, cutting edge thereof, and on said shank portion at a location immediately adjacent the convex outer side of said toe portion.

A trenching chain assembly comprising:

• an elongated endless chain having opposite sides and having a lengthwise aspect and a width, and said elongated endless chain further having a centrally disposed longitudinal axis extending along its length between opposite sides of the chain, said chain including:
• a plurality of pivotally interconnected, articulated links having a plurality of longitudinally spaced, tooth-mounting plates each adapted to support a digging tooth, a plurality of said tooth-mounting plates being located on opposite sides of the longitudinal axis of the chain, and generally defining, by their separation, the width of the chain;
• and
• an array of digging teeth secured to, and projecting from, the chain and a plurality of said tooth mounting plates being located on the same side of the longitudinal axis of the chain, the array of digging teeth including:
• a first L-shaped, trench face shearing tooth mounted on one of said tooth-mounting plates on one side of said chain, and including:
• a shank portion secured to said plate and having a leading edge and a trailing edge;
• a toe portion secured to said shank portion and spaced outwardly from the chain by said shank portion and oriented at an angle of from about 60.degree. to about 120.degree. with respect to said shank portion, and oriented to scrape against a trench face disposed at the leading end of said chain, said toe portion having a sharpened leading cutting edge aligned with the leading edge of said shank portion;
• a hard surface adjacent the sharpened leading edge of said toe portion;
• a second L-shaped trench face shearing tooth disposed on the opposite side of said chain from said first L-shaped tooth, said second L-shaped tooth mounted on a second of said tooth-mounting plates located on the opposite side of the chain from said one tooth-mounting plate and including:
• a shank portion having a leading edge and a trailing edge, said shank portion of the second L-shaped tooth being secured to said second tooth-mounting plate
• a toe portion secured to said shank portion of the second L-shaped tooth and spaced outwardly from said second plate by said shank portion of the second L-shaped tooth, and oriented at an angle of from about 60.degree. to about 120.degree. to said shank portion of the second L-shaped tooth, and oriented to scrape against a trench face ahead of said chain, said toe portion of the second L-shaped tooth having a sharpened leading cutting edge aligned with the leading edge of said shank portion of the second L-shaped tooth;
• a hardened surface area adjacent the sharpened leading edge of said toe portion of the second L-shaped tooth, said toe portion of said second L-shaped trench face shearing tooth extending in the opposite direction from the direction of extension of the toe portion of said first L-shaped trench face shearing tooth and being located substantially the same distance outwardly from the longitudinal axis of said chain as the toe portion of said first L-shaped tooth;
• a first cup-shaped gauge tooth for scraping the side walls of the trench formed by said chain mounted on said chain and spaced longitudinally therealong from each of said L-shaped trench face shearing teeth, said first cup-shaped gauge tooth having;
• a shank portion secured to a third of said tooth-mounting plates spaced longitudinally along the chain from said first and second tooth mounting plates;
• a C-shaped portion joined to said last mentioned shank portion and spaced thereby from said third tooth-mounting plate outwardly in a direction away from the axis of said chain, said C-shaped portion having a leading edge facing toward said L-shaped teeth, and said C-shaped portion having a convex outer surface facing toward, and adapted to bear against, the wall of a trench being formed by said apparatus, and said C-shaped portion further having a concave inner surface facing inwardly toward the axis of said chain;
• and
• a hard-facing material on the leading edge of said first cup-shaped gauge tooth;
• and
• a second cup-shaped gauge tooth for scraping the side wall of a trench formed by said apparatus mounted on said chain and spaced longitudinally therealong from each of said first and second L-shaped trench face shearing teeth, said second cup-shaped gauge tooth having;
• a shank portion secured to a fourth of said tooth-mounting plates;
• a C-shaped portion joined to said last-mentioned shank portion and spaced outwardly from said fourth tooth-mounting plate by said last-mentioned shank portion, said C-shaped portion having a leading edge facing toward said L-shaped teeth and having convex, outwardly facing surface facing toward, and adapted to bear against, the side wall of a trench being formed by said trenching chain assembly, and having a concave, inwardly facing surface;
• and
• a hard facing material on the leading edge of said second cup-shaped gauge tooth.