Cutting apparatus and cutting head therefor

Claim 2

A cutting apparatus including a cutting head, a housing containing a transformer having a primary and secondary windings disposed in said housing and constituting the electric heating means; said cutting head including a pair of contact members which are electrically insulated from each other and are connected to respective ends of said secondary winding; and a cutting blade of substantially uniform thickness over its length having two legs and adapted to be mounted in said head such that each leg is in electrical engagement with one said contact member so that said blade legs in operation short-circuit said secondary winding, whereby said blade will be rapidly heated up on energization of said primary winding, said blade being flat in the plane of cutting; said cutting head being disposed at one end of said housing, a pivotally mounted cranked actuating lever being carried by the other end of said housing; pivotal movement of said lever causing said blade to move relative to the cutting plane; an electric switch which is so disposed at said other end of the housing that pivotal movement of said lever in one angular sense causes said switch to be operated to switch on the heating for the blade.

Claim 3

A cutting apparatus including a cutting head, a housing containing a transformer having a primary and secondary windings disposed in said housing and constituting the electric heating means; said cutting head including a pAir of contact members which are electrically insulated from each other and are connected to respective ends of said secondary winding; and a cutting blade of substantially uniform thickness over its length having two legs and adapted to be mounted in said head such that each leg is in electrical engagement with one said contact member so that said blade legs in operation short-circuit said secondary winding, whereby said blade will be rapidly heated up on energization of said primary winding, said blade being flat in the plane of cutting; rotatable guide rollers mounted on said housing; said rollers including three co-axial rollers mounted at the rear of the housing relative to the direction of cutting; a shaft extending laterally from the housing, one of said rollers being mounted on said shaft.

Claim 4

A cutting apparatus including a cutting head, a housing containing a transformer having a primary and secondary windings disposed in said housing and constituting the electric heating means; said cutting head including a pAir of contact members which are electrically insulated from each other and are connected to respective ends of said secondary winding; and a cutting blade of substantially uniform thickness over its length having two legs and adapted to be mounted in said head such that each leg is in electrical engagement with one said contact member so that said blade legs in operation short-circuit said secondary winding, whereby said blade will be rapidly heated up on energization of said primary winding, said blade being flat in the plane of cutting; rotatable guide rollers mounted on said housing; said rollers including three co-axial rollers mounted at the rear of the housing relative to the direction of cutting; a shaft extending laterally from the housing, one of said rollers being mounted on said shaft.

Claim 5

Apparatus as claimed in claim 20 wherein the other two of said rollers are adjacent the said longitudinal axis, while said one roller is disposed at the end of said shaft; said shaft having a length substantially equal to half the width of the housing.

Claim 6

A cutting apparatus including a cutting head, a housing containing a transformer having a primary and secondary windings disposed in said housing and constituting the electric heating means; said cutting head including a pair of contact members which are electrically insulated from each other and are connected to respective ends of said secondary winding; and a cutting blade of substantially uniform thickness over its length having two legs and adapted to be mounted in said head such that each leg is in electrical engagement with one said contact member so that said blade legs in operation short-circuit said secondary winding, whereby said blade will be rapidly heated up on energization of said primary winding, said blade being flat in the plate of cutting; said cutting head further comprising a pair of clamping plates, one for each said contact member, for clamping one said blade leg against the respective said contact member; said housing having an internal recess between said contact members; one of said clamping plates being located in said recess and being adjustably secured to one of said contact members, while the other said clamping plate is rigidly secured to the other contact member on the side thereof remote from said internal recess.

Claim 7

A cutting apparatus including a cutting head, a housing containing a transformer having a primary and secondary windings disposed in said housing and constituting the electric heating means; said cutting head including a pair of contact members which are electrically insulated from each other and are connected to respective ends of said secondary winding; and a cutting blade of substantially uniform thickness over its length having two legs and adapted to be mounted in said head such that each leg is in electrical engagement with one said contact member so that said blade legs in operation short-circuit said secondary winding, whereby said blade will be rapidly heated up on energization of said primary winding, said blade being flat in the plate of cutting; said cutting head further comprising a pair of clamping plates, one for each said contact member, for clamping one said blade leg against the respective said contact member; said housing having an internal recess between said contact members; one of said clamping plates being located in said recess and being adjustably secured to one of said contact members, while the other said clamping plate is rigidly secured to the other contact member on the side thereof remote from said internal recess.

Claim 8

Apparatus as claimed in claim 4, wherein said side of the other contact member is formed with an oblique guide surface, one end portion of the other clamping plate engaging said guide surface while the other end portion clamps the blade.