Cutting processes employing a laser

Claim 2

A method in accordance with claim 1, in which the workpiece and suction chamber are stationary and the laser beam moves with respect to the workpiece and suction chamber, and in which the suction chamber includes one side which serves as a support for the workpiece during the said movement, the said side being formed with a slot extending along the required line of cut.

Claim 3

Apparatus for cutting a workpiece, comprising: a chamber having a surface for supporting the workpiece, at least a portion of said surface being in the form of a grid; a laser; means for directing a beam of coherent radiation from the laser through a gaseous medium to a workpiece placed on said grid surface of said chamber and focusing said beam at said workpiece; a layer of refractory material located in the path of said laser beam within said chamber; pumping means for establishing in said chamber a pressure substantially less than the pressure of said gaseous medium on the side of said workpiece remote from said chamber; and means effecting relative movement of said workpiece and said focused laser beam; whereby during such relative movement the laser beam cuts the workpiece along a line overlying said grid-supporting surface and the gaseous medium is drawn through the cut and grid surface into the said chamber.

Claim 4

A method in accordance with claim 1, further comprising creating on the side of the workpiece on which the laser is located and around the point of the workpiece at which the laser beam is directed an atmosphere of a gas which is so selected in relation to the material of the workpiece that the gas reacts exothermically with the workpiece, whereby when the cut is commenced the said gas is drawn through the cut into the said chamber and reacts exothermically with the workpiece in passing through the latter.

Claim 5

A method in accordance with claim 5, in which the workpiece is of metal and in which, prior to a cutting operation, a buffer layer of nonmetallic material is placed between the metal workpiece and the said chamber.

Claim 6

Apparatus for cutting a workpiece, comprising: a chamber having an aperture in its upper surface; a layer of refractory material located within said chamber at the base of said chamber; a laser; means for directing a beam of coherent radiation from said laser through a gaseous medium to a point on said workpiece located above the aperture in the said upper surface of said chamber, said laser beam and aperture being aligned with said refractory material in the base of said chamber; a coiled pipe surrounding said chamber for carrying a liquid coolant to remove heat from said chamber; pumping means for establishing within said chamber a pressure substantially less than the pressure of said gaseous medium on the side of the workpiece remote from said chamber; and means effecting relative movement of said workpiece, on the one hand, and said chamber and laser beam, on the other hand, whereby during such relative movement the laser beam cuts the workpiece and then the gaseous medium is drawn through the cut and aperture into said chamber.

Claim 7

Apparatus for cutting a workpiece, comprising: a chamber having an apertured surface for supporting the workpiece, said chamber having a layer of refractory material at its base; a hood located over said apertured surface on the side of said surface remote from said chamber; a laser; means for directing a beam of coherent radiation from said laser through said hood on to a workpiece supported by said surface and focusing said laser beam at said workpiece; means establishing within said hood an atmosphere of a gas exothermically reactive with said workpiece; pumping means for establishing within said chamber a pressure substantially less than the pressure of said exothermically reactive gas within said hood; and means effecting relative movement of said workpiece and said focused laser beam, whereby during such relative movement the laser beam cuts the workpiece and the exothermically reactive gas is drawn through the cut in the workpiece and through the apertured surface into the said chamber.

Claim 8

Apparatus for cutting a workpiece comprising: a laser, a rotary member having its interior separated into segments and having an opening extending around its periphery; means for directing a beam of coherent radiation from said laser through a gaseous medium towards the opening at a point in the periphery of said rotary member; means for rotating said rotary member to bring the peripheral surface of each segment in turn into the path of the laser beam; a vacuum-pumping device and stationary means for connecting said vacuum-pumping device to each segment in turn of said rotary member as it rotates, whereby a partial vacuum is established in each segment in turn as it approaches its intersection with the laser beam path; a layer of refractory material located in the base of each segment of said chamber; whereby when a workpiece is supported at the periphery of said chamber between said laser beam and said chamber and the beam cuts the workpiece along a line overlying the opening in said chamber periphery, the gaseous medium is drawn through the cut and the opening into the underlying segment of said chamber.