US 4,711,030 A · Variable speed fillet knife

Abstract

A portable, hand-held electric knife having dual cutting blades is powered by a DC electric motor which draws its operating current from a remote storage battery. The cutting blades are mechanically coupled to the armature shaft of the DC electric motor by a gear assembly in which a pair of bevel gears are mounted for free rotation on a support shaft and are engaged by a beveled pinion gear attached to the rotor armature. Each blade is movably coupled to a selected bevel gear by a pin. In response to rotation of the drive pinion, the beveled gears are driven in counter-rotating motion. As the driven gears rotate, the blades are extended and retracted in side-by-side relation. A fulcrum shaft is received through aligned slots formed in the blades. Linear reciprocating movement of the blades relative to each other is stabilized and arcuate reciprocating movement of the coupled blades is effected as the blades pivot about the fulcrum shaft. According to this arrangement, the coupled blades undergo simultaneous linear reciprocal movement along parallel paths of extension and retraction, and arcuate reciprocal movement about a path transverse thereto.

Claims6

Dependent claims

A portable, hand-held electric knife having dual cutting blades, a DC electric motor, power conductors electrically connected to the DC electric motor for conducting current from a remote storage battery, the DC electric motor including an armature shaft and a gear assembly mechanically coupling the dual cutting blades to the armature shaft, the gear assembly including a support shaft, a pair of bevel gears mounted for rotation on opposite ends of said support shaft, a beveled pinion gear engaged with said first and second bevel gears, said beveled pinion gear being mechanically coupled to the armature shaft of said DC electric motor, each cutting blade including a force transmitting end member movably coupled to one of the beveled gears for converting rotary motion of said armature shaft to linear counter-reciprocating motion of said cutting blade, each cutting blade having an elongated slot formed intermediate the force transmitting member and the cutting end, with the respective elongated slots being disposed in overlapping alignment with each other;

and, a fulcrum shaft lodged within said housing and projecting through said overlapping slots.

An electrically-operated knife comprising, in combination:

a housing having a portion defining a handle;
an electric motor mounted on said housing within said handle portion, said motor having a rotor;
first and second cutting blades movably coupled together, said first and second cutting blades each having a force transmitting end portion for insertion into said housing, each cutting blade having a longitudinal slot formed in said blade near said force transmitting end portion;
means coupled to said cutting blades for constraining counter-reciprocating movement of said blades along parallel linear paths in extension and retraction while permitting reciprocating pivoting movement of said blades through an arcuate path relative to said handle portion, said constraining means including a fulcrum pin mounted on said housing, said fulcrum pin being received within said longitudinal slots in said cutting blades;
and,
rotary motion converting means coupled to said rotor and to the force transmitting end portions of said first and second cutting blades for extending and retracting said blades relative to each other while simultaneously reciprocating said blades through said arcuate path.

3 more elements

Dependencies are inferred from the claim text.

Variable speed fillet knife

Life of this patent

Variable speed fillet knife

Life of this patent

Abstract

Claims6