Hedge trimmer with combination shearing and sawing blade assembly

A method of cutting vegetation comprising the steps of:

• providing a hedge trimmer having a housing, a motor assembly contained in said housing, a blade assembly having first and second blades extending in a lengthwise direction from said housing, and a drive mechanism coupling said first blade to an output of said motor assembly for causing reciprocating movement thereof relative to said second blade, said first blade having an alternating series of cutter teeth and sizing lugs formed along at least one longitudinal edge for establishing entrapment channels therebetween, each cutter tooth having a shear tooth segment formed along its opposite lateral edges and a saw tooth segment formed along its distal edge, and said second blade having comb teeth formed along a longitudinal edge which overlap said cutter teeth on said first blade;
• introducing plant growth to be cut into a cutting pathway established between said first and second blades of said blade assembly;
• drawing small plant growth of a size below a threshold size limited into said entrapment channels;
• shearing said small plant growth between a shear tooth segment and a comb tooth during a single stroke of said first blade relative to said second blade;
• drawing large plant growth of a size exceeding said threshold size limit against said sizing lugs and into alignment with said saw tooth segments;
• and
• sawing said larger plant growth received between said comb teeth with said saw tooth segments of said cutter teeth during multiple strokes of said first blade relative to said second blade.

A hand-held power-operated tool for cutting plant growth, comprising:

• a housing;
• a first blade having a series of cutter teeth formed along at least one of its longitudinal edges and sizing lugs formed between adjacent cutter teeth for establishing entrapment channels therewith, each of said cutter teeth having a shear tooth segment formed along its opposite lateral edges and a saw tooth segment formed at its distal end between said shear tooth segments, whereby plant growth of a size up to a predetermined size limit is permitted to enter said entrapment channels for alignment relative to shear tooth segments and plant growth exceeding said predetermined size limit is prevented from entering said entrapment channels for alignment relative to said saw tooth segments;
• a second blade having a series of comb teeth formed along a longitudinal edge thereof that overlap said cutter teeth on said first blade, said comb teeth include a first comb tooth segment arranged to cooperate with a corresponding shear tooth segment of said cutter teeth for shearing plant growth therebetween in response to a single stroke of said first blade relative to said second blade, and a second comb tooth segment arranged to retain plant growth exceeding said predetermined size limit between adjacent comb teeth and relative to said saw tooth segments of said cutter teeth for sawing such plant growth in response to multiple strokes of said first blade relative to said second blade;
• and
• a power-operated mechanism contained in said housing and coupled to said first and second blades for causing reciprocating relative movement therebetween.

A blade assembly for a hedge trimmer comprising:

• a first blade having a series of cutter teeth formed along at least one of its longitudinal edges with each of said cutter teeth having a shear tooth segment formed along its opposite lateral edges and a saw tooth segment formed at its distal end between said shear tooth segments, said first blade further having sizing lugs that are formed between adjacent cutter teeth for establishing entrapment channels therewith such that smaller plant growth of a size up to a predetermined size limit can enter said entrapment channels for alignment relative to shear tooth segments, and larger plant growth exceeding said predetermined size limit abuts one of said sizing lugs for preventing entrance into said entrapment channels for alignment relative to said saw tooth segments of said cutter teeth;
• a second blade having a series of comb teeth formed along a longitudinal edge thereof that overlap said cutter teeth on said first blade, said comb teeth cooperate with said shear tooth segments for shearing said smaller plant growth introduced therebetween during a single stroke of said first blade relative to said second blade, and said comb teeth align said larger plant growth therebetween for holding the larger plant growth relative to said saw tooth segments for sawing such larger plant growth during multiple strokes of said first blade relative to said second blade.

A blade assembly for a portable power-operated tool of the type having a housing containing a motor, said blade assembly comprising first and second elongated blades extending forwardly in a lengthwise direction from the housing with said first blade coupled to an output of the motor for causing reciprocating rectilinear movement thereof relative to said second blade, said first blade having a series of cutter teeth extending outwardly from at least one of its longitudinal edges, each of said cutter teeth having a compound toothform including a shear tooth segment formed along each lateral edge and a saw tooth segment formed at a distal end between said shear tooth segments, said first blade further including sizing lugs formed between adjacent cutter teeth for permitting alignment of smaller plant growth up to a predetermined size limit relative to an adjacent one of said shear tooth segments and for aligning larger plant growth exceeding said predetermined size limit relative to said saw tooth segments, said shear tooth segments cooperating with comb teeth formed on said second blade for shear-cutting said smaller plant growth introduced therebetween during a single stroke of said first blade relative to said second blade, and said saw tooth segments being arranged for saw-cutting said larger plant growth with multiple strokes of said first blade relative to said second blade.

A blade assembly for use in a portable power-operated tool comprising a cutting blade having cutter teeth formed on at least one longitudinal edge and which is reciprocated relative to a combing blade, said cutter teeth having a pair of shear tooth segments and a saw tooth segment between said shear tooth segments, said combing blade comprising a series of comb teeth adapted to cooperate with said shear tooth segments of said cutting blade for shearing smaller plant growth introduced therebetween during a single stroke of said cutting blade, said comb teeth adapted to cooperate with said saw tooth segments for sawing larger plant growth with multiple strokes of said cutting blade, said comb teeth each including a first comb tooth segment arranged to cooperate with a corresponding shear tooth segment for shearing said smaller plant growth introduced therebetween, and a second comb tooth segment arranged to retain said larger plant growth exceeding a predetermined size limit between adjacent comb teeth and relative to said saw tooth segments of said cutter teeth for multi-stroke saw-cutting thereof;

• wherein each of said first comb tooth segments is symmetrical about a comb tooth centerline and includes a pair of oppositely facing angled lateral edge surfaces that are outwardly convergent toward said comb tooth centerline, and wherein said outwardly convergent angled lateral edge surfaces of said first comb segments cooperate with lateral edges of said shear tooth segments to generate a progressive shear cutting action in response to the reciprocating movement between said blades.