In the past, various condition responsive mechanisms utilized a sensing device for ascertaining temperature changes and effecting operation of such condition responsive mechanisms in response to such temperature changes. These sensing devices may comprise an expansible bellows communicated with a generally elongate metallic capillary tube, and such bellows and tube are charged with a temperature sensitive pressure fluid, such as a liquid or a gas for instance. One of the aforementioned condition responsive mechanisms is illustrated in U.S. Pat. No. 3,648,214 issued Mar. 7, 1972 to John L. Slonneger which is incorporated by reference herein.
Numerous arrangements were known in the past for crimping, i.e. closing and sealing, one or both ends of the aforementioned capillary tube to confine the pressure fluid therein. One typical arrangement was to flatten the tube in a limited region thereof and thereafter effect a welding operation on such flattened region. For example, two or more welds were made across the flattened region of the capillary tube, i.e. transverse to the lengthwise direction of the tube, and the tube was then severed between a pair of those cross-wise welds so as to provide adequate sealed ends of the tube. In another past crimping arrangement, a tube end was crimped into a semi-circular congifuration and thereafter such crimped tube end was sealed by welding or soldering. It is believed that, at least with capillary tube metals, the heating effected during a welding or soldering operation might have a deleterious affect on the physical properties of such metals. In another past crimping arrangement, a metallic capillary tube had its opposite sides collapsed inwardly between a pair of crimping jaws, and while confining these collapsed opposite sides, another pair of crimping jaws were operated to collapse a portion of the tube with sufficient force to sever the tube forming a tapering cold welded end thereon.