System for Relieving Stress at the Top and Bottom of Vertically Tubular Members In Vertically Moored Platforms (Patent No: 890147)

Inventor: Dixon, David A.

Location: Tulsa, OK

Comments: N/A

Description: THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An offshore structure for use in a body of water having a floor which comprises:
a floating structure supported by said body of water;
elongated members connecting and anchoring said structure to anchor means in the floor of the body of water;
upper stop means near the upper end and lower stop means near the lower end of said elongated member to restrict the angular deflection of said elongated member, said upper stop means supported from said floating structure and said lower stop means supported from the floor of said body of water.

2. A structure as defined in Claim 1 in which each said stop means includes a ring surrounding each elongated member and means to rigidly support each such ring.

3. A structure as defined in Claim 1 in which said stop means includes a first ring and a second ring, said second ring being between said first ring and the end of said elongated member, said second ring member having a smaller diameter than the first ring member of said stop means.

4. A structure as defined in Claim 3 in which said first ring is about twice as far from the end of said elongated member as is said second ring.

5. A structure as defined in Claim 1 in which said stop means includes two diaphragms, one elastically supported with a resiliency according to equation 2 of the specification hereof from said floating structure and the other similarly elastically supported from the floor of said body of water, as a part of said stop means and in which said elongated member passes through said diaphragm in intimate contact therewith.

6. A structure as defined in Claim 1 in which said stop means includes a post member supported within said elongated member and terminating near one end thereof and extending to within the ocean floor and spacer means between said post member and said elongated member.

7. Structure for relieving stresses at the top and bottom of an elongated tubular member which is used to connect a floating structure supported by a body of water to anchors in the floor there of, which comprises:
a first ring-like member supported from the bottom of said body of water and surrounding said elongated tubular member near the lower end of said elongated tubular member and a second ring-like member supported from said floating structure and near the upper end of said elongated tubular member; and
a diaphragm within each said ring-like member, the outer periphery of said diaphragm being secured to said ring-type member, said elongated tubular member passing through said diaphragm in intimate contact therewith.

8. A structure as defined in Claim 7 in which the position of the diaphragm is chosen such that the following equation (whose terms are defined in the specification) is satisfied:



9. Structure for relieving stresses at the top and bottom of elongated members which are used to connect a floating structure which is supported by a body of water to anchor means in the floor thereof, said elongated members being parallel, said floating structure being free of any other anchoring connecting to the floor thereof except for said elongated members, which comprises:
means supported from said floating structure near the upper end of each said elongated member to restrict the angular deflection of each said elongated member at such points; and
means supported from the floor of said body of water near the lower end of each said elongated member to restrict the angular deflection of each said elongated member at such points.