Patent ID: 8322186

Claim:
A method of forming an apparatus for use as a turbulizer or fin for a heat exchanger, the apparatus including a member having a longitudinal axis and a lateral axis, a length measured in the direction of the longitudinal axis, a width measured in the dimension of the lateral axis and a plurality of strips including one or more first strips and one or more second strips, each strip extending in the direction of the lateral axis and being corrugated so as to form a plurality of sections spaced-apart from one another in the direction of the lateral axis and connected to one another by bridges projecting from the sections in a common direction normal to both the lateral and longitudinal axes, wherein the bridges of the first strips and the second strips extend in the same direction and the corrugations of the one or more second strips are offset in the direction of the lateral axis from the corrugations of the one or more first strips, the method comprising: crimping strip material between first and second forming dies to form said apparatus, the strip material having a length measured in the direction of the longitudinal axis, a width measured in the dimension of the lateral axis and a plurality of corrugations each extending laterally, said dies being shaped such that, as the strip material is crimped between the first and second forming dies, substantially all movement of strip material in the direction of the lateral axis in the crimping step occurs as a result of strip material being drawn in the direction of the lateral axis by material that has been displaced in a direction parallel to the direction of relative die movement.