Pipe coupling
Patent 3971574 Issued on July 27, 1976. Estimated Expiration Date: 
July 27, 1993. 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.
July 27, 1993. 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 339036 2933428 3826521 InventorApplicationNo. 537093 filed on 12/30/1974US Classes:285/31, Inserted section285/330, Interlocked or overlapped285/423, Nonmetallic285/915MASTICExaminersPrimary: Callaghan, Thomas F.Attorney, Agent or FirmAbstractA coupling for unthreaded pipes of a sprinkler system, which permits the replacement of a small damaged pipe section without bending the pipes already emplaced in the ground. One coupling includes a short pipe section having an enlaged tubular portion fixed at one end thereof adapted to be fitted over and adhered to a first open end of the pipe in the ground. A slidable sleeve on a second end of the pipe section has an enlarged tubular portion adapted to be fitted over and adhered to a second open end of the pipe in the ground. | |
