Trip edge snowplow

A trip edge snowplow comprising:

• a mould board having a lower edge;
• a trip plate having a scraping edge and an upper edge;
• and
• self-adjusting links mounting said trip plate on said mould board adjacent said lower edge;
• said self-adjusting links including:
• an elongate spring lever having a first end engaging said mould board and a second end engaging said trip plate;
• and
• a stop lever having one end engaging said mould board and another end engaging said trip plate so that said trip plate can be displaced upwardly and extend backwardly away from said lower edge of said mould board;
• and said scraping edge extends from an undisplaced position ahead of said lower edge to a displaced position behind said lower edge, said scraping edge extending no further downward from said lower edge of said mould board than when said trip plate is in said undisplaced position wherein said upper edge is forward of said mould board in said displaced position.

A trip edge snowplow comprising:

• a mould board having a lower edge;
• a trip plate mountable adjacent said lower edge in cooperating association with said mould board;
• an elongate spring lever having a first end pivotally engaging said mould board and a second end pivotally engaging said trip plate;
• a stop lever having one end pivotally engaging said mould board and another end pivotally engaging said trip plate so that said trip plate can swing up and away from said lower edge of said mould board;
• and
• an elongate compression member having one end pivotally coupled to said mould board and another end pivotally coupled to said spring lever between said first and second ends;
• said elongate compression member providing a progressively increasing restoring force with progressively increasing displacement of said one end of said compression member toward said other end of said compression member;
• said compression member and said spring lever being oriented relative to each other and to said mould boards so that the moment arm between said compression member and said mould board progressively decreases with progressively increasing displacement of said one end of said compression member toward said other end of said compression member so as substantially to compensate for said progressively increasing restoring force and thereby bias said trip plate relative to said mould board with a substantially constant bias force.

A trip edge snowplow comprising:

• a mould board having a lower edge;
• a trip plate having a scraping edge;
• and
• self-adjusting links mounting said plate adjacent said lower edge, for motion with respect to said mould board;
• said self-adjusting links including:
• an elongate spring lever having a first end engaging said mould board and a second end engaging said trip plate;
• and
• a stop lever having one end engaging said mould board and another end engaging said trip plate, and said scraping edge is displaced upwardly and extends backwardly from an undisplaced position ahead of said lower edge, substantially along an axis offset at least thirty degrees from vertical, to a displaced position behind and no further downward from said lower edge while enabling snow plowing to be performed at substantially full capacity by both a portion of said trip plate extending in front of said mould board and said mould board.