Counterbalanced reciprocating mechanism

A reciprocating saw comprising,

• a housing including a gear case,
• a motor in said housing and having a motor shaft,
• a jackshaft rotatably mounted in said housing parallel to said motor shaft,
• gearing connecting said motor shaft to said jackshaft,
• a spindle mounted in said gear case for reciprocating motion,
• a counterweight mounted in said gear case for reciprocating motion parallel to said spindle,
• primary and secondary wobble plates mounted on said jackshaft and connected to said spindle and said counterweight respectively,
• said wobble plates being at an angle with respect to each other to reciprocate said spindle and said counterweight in opposite directions.

A reciprocating saw comprising,

• a housing including a gear case,
• a motor in said housing and having a motor shaft,
• a jackshaft rotatably mounted in said housing parallel to said motor shaft,
• gearing connecting said motor shaft to said jackshaft,
• a primary bearing mounted at an angle on said jackshaft,
• a primary wobble plate mounted on said primary bearing and including a drive arm,
• a spindle mounted in said gear case for reciprocating motion,
• said drive arm being connected to said spindle to reciprocate said spindle as said jackshaft is rotated,
• a counterweight mounted in said gear case for reciprocating motion parallel to said spindle axis,
• a second bearing mounted at an angle on said jackshaft,
• a second wobble plate mounted on said second bearing and having a drive arm connected to said counterweight,
• said primary and secondary wobble drive arms being angularly offset with respect to the axis of said jackshaft,
• the planes of said primary and secondary bearings being offset from 180.degree. apart by substantially the same angle as the angular offset of said drive arms.

A reciprocating saw comprising,

• a housing including a gear case,
• a motor in said housing and having a motor shaft,
• a jackshaft rotatably mounted in said housing parallel to said motor shaft,
• gearing connecting said motor shaft to said jackshaft,
• a primary bearing mounted at an angle on said jackshaft,
• a primary wobble plate mounted on said primary bearing and including a drive arm,
• a spindle mounted in said gear case for reciprocating motion,
• said drive arm being connected to said spindle to reciprocate said spindle as said jackshaft is rotated,
• a counterweight mounted in said gear case for reciprocating motion parallel to said spindle,
• a second bearing mounted at an angle on said jackshaft,
• a second wobble plate mounted on said second bearing and having a drive arm connected to said counterweight,
• said drive arms reciprocating said spindle and said counterweight in opposite directions to substantially cancel out the axial vibrations induced by such reciprocation.

A reciprocating drive mechanism comprising,

• a housing,
• a spindle mounted in said housing for reciprocating motion,
• a counterweight mounted in said housing coaxial with said spindle and moveable relative to said spindle, and
• first and second drive means for reciprocating said spindle and said counterweight in opposite directions so the axial forces induced by reciprocation are substantially cancelled,
• said first and second drive means being of the same type so the forces induced in one drive means substantially cancel the forces induced in the other drive means.

A reciprocating drive mechanism comprising,

• a housing,
• a spindle mounted in said housing for reciprocating motion,
• a counterweight mounted in said housing for reciprocating motion relative to said spindle,
• said spindle and said counterweight being concentric, and
• first and second drive means for reciprocating said spindle and said counterweight in opposite directions so the axial forces induced by reciprocation are substantially cancelled,
• said first and second drive means being of the same type so the forces induced in one drive means substantially cancel the forces induced in the other drive means.