Cylindrical containers by hour glass formation of metal tubes
Patent 4007616 Issued on February 15, 1977. Estimated Expiration Date: 
February 15, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 15, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 545022 2051949 3735463 3740991 InventorAssigneeApplicationNo. 629648 filed on 11/06/1975US Classes:72/38, WITH EXPOSURE OF WORK TO GAS, VAPOR, MIST, OR MODIFIED ATMOSPHERE72/302, Substantially direct approach or recession (e.g., stretching)72/342.5, And heating of work72/378By application of tensile forcesExaminersPrimary: Larson, Lowell A.Attorney, Agent or FirmAbstractA process of manufacture to produce low cost pressure vessels from a length of metal tubing by use of localized heat and/or axial tensile force to shrink the diameter of the tubing at selected locations of a predetermined starting length approximately one diameter long and many diameters apart to permit subsequent separation to form open-ended pressure vessels. Subsequent conventional swaging operations could thicken and reduce the end diameters so they can be threaded. | |
