The present application relates to a personnel transfer device for offshore use to transfer personnel and cargo, between floating vessels and offshore drilling or production platforms.
A personnel or cargo net as disclosed in U.S. Pat. No. 3,827,745 and further according to U.S. Pat. No. 4,883,301, has been a favorite device for transfer personnel and cargo, between floating vessels and offshore drilling or production platforms.
Referring to
The expander post 16 is sufficiently strong to impart a rigid connection between the base and the top and to impart significant tension to the lacings 18. For example, an aluminum tube having a nominal size of 4″ schedule 80 has been found to work in one exemplary construction. The expander post 16 may also be disassembled and removed to allow the top 14 and the base 12 to be collapsed together for convenient storage without removing the lacings 18.
The base 12 may comprise a spreader ring 20 supporting a coupler 22. In the embodiment depicted the spreader ring 20 has a circular shape with periphery 24 having a diameter Db sufficiently large (for example 5′ to 7′ Dia.) to allow personnel to be carried thereon and the coupler 22 is supported centrally located as with supports 26. A platform 28 is also provided extending at least partially between the spreader ring 20 and the coupler 22 to permit personnel to stand on the platform 28. The platform 28 may also be supported by the supports 26. It has been found that a strong light weight metal tubing, such as aluminum tubing, may be used in the construction of the spreader ring 20 and also for the supports 26 and the expander post 16. For example, aluminum tubing having a nominal size of 1½″ schedule 40 has been found to work in one exemplary construction. The platform 28 may be constructed of an light weight sheet material having a non-slip surface, such as diamond plate or expanded-metal grating. All of the metal material may be constructed of the same metal to reduce the adverse effect of cathode/anode induced corrosion. The periphery 24 of the spreader ring 20 maybe surrounded with a flotation padding 30, preferably having both significant buoyancy to help float the device and cushioning to reduce consequences from inadvertent side impact. The padding 30 may be fastened to the spreader ring and covered with a durable protective covering 31.
The top 14 may also comprise a top spreader ring 32 supporting a coupler 34. In the embodiment depicted the spreader ring 32 has a circular shape with periphery 36 having a diameter Dt approximately the same as the base diameter Db to provide a convenient place for attachment of lacings 18 so that the lacings are substantially vertical between the base and top when the lacings are placed in tension. The coupler 34 is supported centrally located as with supports 38. A roof 40 is also provided extending at least partially between the top spreader ring 32 and the coupler 34 to allow personnel standing on the base 12 to have protection from above when standing on the platform 26. The roof 40 may also be supported by the radial supports 38. The periphery 36 may be surrounded with a flotation padding 42 attached to the spreader ring 32 and covered with a protective covering 43.
Referring to
In the exemplary embodiment shown, the attachments of the lacing, as at a plurality of base attachments 44 and top attachments 46, may be conveniently formed with loops around the spreader rings 20 and 32 respectively. The attachment loops at 44 and 46 may be securely formed at opposed ends of the lacings 18. High strength non-stretch lacings are desired. For example, it has been found suitable to construct such lacings from a high strength multi-stranded fiber, material, known as AMSTEEL® twelve strand, 9/16 inch, diameter, high molecular weight polyethylene (12 s, 9/16″, HMWPE) available from Samson Rope Company. The manufacturer rates this material as having an average strength of 30,800 lbs. It has been found that such strong lacings attached at the periphery will become taught and therefore substantially “rigid” when the lacings are placed in tension and thereby form a barrier against side impact.
Referring to
For ease of construction and for strength and durability of the personnel transportation device 10, the base 12 may further include a base inner ring 52 concentric with the outer spreader ring 20 and supported by the supports 28 between the outer spreader ring 20 and the base coupler 22. Similarly the top 14 may be constructed with a top inner ring 54 concentric with the outer top spreader ring 32 supported by the supports 38 between the top coupler 34 and the top spreader ring 32. In such an exemplary embodiment of the personnel transfer device, the outer set 19 of lacings 18 may be attached to the outer base and top spreader rings, 20 and 32, respectively. The inner set 17 of the lacings 18 may be attached to the inner base 52 and top inner top ring 54.
Referring to
Referring to
In the exemplary embodiment depicted, at least one of the couplers 22 or 34 (top coupler 34 is depicted with threads in
The base coupler 22 has an inside diameter for receiving the outside diameter of the lower portion 70 of the expander post 16. The expander post 16 fits closely within the base coupler 22 to provide coupling support while permitting relative rotation between the coupler 22 and the expander post 16. To further facilitate relative rotation, the inside of the coupler 22 is provided with a closed end 74 and with a friction reduced plate 76 or washer against which the end 74 of lower portion 70 may rotate. The reduced friction plate 76 might for example be constructed of a durable plastic or polymeric material. The lower portion 70 of the expander post 16 may also be provided with a closed end 80 to increase the engagement surface area with the coupler end 74. After rotation to the desired expanded length the lower portion 70 may be secured against rotation by a means for securing 82 such as a bolt 82a or pin through aligned holes 82b and 82c or other means for securing the expander post 16 and base coupler 22 against relative rotation or decoupling. While it is desirable for permitting moisture to drain from the threads in the top coupler 34, it will be understood that the construction might be reversed, with base coupler 22 being threaded and the lower portion 70 of the expander post 16 being threaded, without departing from certain aspects of the present invention. Other means for expanding the expander post 16, that are equivalent to the means and function describe, might also be employed without departing form certain aspects of the invention.
In the exemplary embodiment depicted, the expander post 16 is also constructed to permit it to be disassembled and thereby to allow the personnel transfer device to be collapsed for storage. An intermediate coupler 84 is provided for coupling the upper portion 68 and the lower portion 70 of the expander post 16. In this embodiment the intermediate coupler 84 is secured to the upper portion 68 of the expander post 16 with a means for securing 86, such as a bolt 86a or pin through aligned holes 86b and 86c or other means for securing the expander post 16 and coupler 84 against relative rotation or decoupling. Similarly the intermediate coupler 84 is secured to the lower portion 70 of the expander post 16 with a means for securing 88, such as a bolt 88a or pin through aligned holes 88b and 88c or other means for securing the expander post 16 and the intermediate coupler 84 against relative rotation or decoupling. The handles 72, for activating the expander post 16 to expand by manual rotation, are rigidly affixed as by welding or otherwise to the intermediate coupler 84.
In the embodiment shown the expander post 16 is further constructed with an upper portion 68 and a lower portion 70, inter-connected at an intermediate coupler 84. In this embodiment the top coupler 34 and the upper portion 68 of the expander post 16 are treaded. This orientation of the threads may facilitate drainage of moisture and thereby keep the threads in a better condition for smooth operation. The lower portion 70 is inserted into the base coupler 22 and secured thereto at securing means 82 as described above. The intermediate coupler 84 is rigidly attached to the upper threaded portion 68 of the expander post 16 and is provided with handles 72 so the intermediate coupler 84 may be manually rotated, and thereby rotating the upper threaded portion 68 of the expander post 16 within top coupler 34. The intermediate coupler 84 is also detachably secured to the lower portion 70 of expander post 16 as described above. It will be understood that to rotate the upper portion 68 of the expander post 16, either the intermediate coupler 84 should be un-secured, unbolted or unpinned, from the lower portion 70 or the lower portion 70 should be unsecured, unbolted or unpinned, from the base coupler 22, to thereby allow relative rotation of the threaded portion 68 of the expander post 16 and the treaded coupler 34 while still vertically coupled. After the threaded portion 68 is engaged in threaded coupler 34 and rotated sufficiently to expand the distance between the top 14 and base 12 sufficiently to provide the desired tension in the lacings 18, the unsecured portions of expander post 16 are then re-secured.
Referring to
The tubular spreader rings, spacer bars, inner rings, supports, coupler and platform may all be constructed of aluminum to provide a light weight structure that can be welded together. For added strength, and particularly for strength at interconnecting segments, the tubular rings 21 and 23 may further be provided with reinforcement bars 25, rolled inside to the tubular rings 21 and 23. The platform 28, as indicated may be a plate, grating, or screen material to facilitate non-slip standing by personnel being transferred thereon.
The top spreader ring 32 and top inner ring 54 may also be constructed of rolled tubular metal connected together and to a centrally located top coupler 34 with radial supports 38. To provide added support a treaded top coupler 34, the radial supports 38 may be in the form of triangularly shaped plates. All the top spreader ring 32, top inner ring 54, supports 38, and top coupler 34, may be constructed of aluminum for strong, light weight and conveniently welded construction.
In an exemplary embodiment, the floatation padding 30 may be conveniently attached to an expander ring with an attachment mechanism 92 as depicted in
Referring to
It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, terms with directional connotations such as base, top, upper, lower, outer, and inner are used in context for purposes of relative positions and the device need not be limited to absolute directions in order to fall within the scope of the invention described and claimed. While various features and embodiments are described in certain combinations and sub-combinations selected features from one embodiment may be combined with features of other embodiments without departing from certain aspects of the invention.
The lacings 18 may alternatively be constructed of successive layers of polyurethane, fiberglass resin, and polypropylene rope, as described in U.S. Pat. No. 4,789,045, incorporated herein by reference. Other means for attachment and other types of lacings that are flexible when relaxed and strong and substantially “rigid” in tension may be employed without departing from certain aspects of the invention.
The expander post may be another means for expanding the distance between the base and the top to tension the lacings 18. The activation into expansion was shown as a manual treaded device but might be a cam actuated device, a hydraulically actuated or electrically actuate expansion device that can be secured into place when the expansion is completed, without departing from certain aspects of the invention.
The securing means are shown as bolts but may be other removable fastener devices without varying from certain aspects of the invention.
The construction is shown as aluminum but could be other construction with sufficient strength and durability.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many other modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as claimed in the claims that follow and to which applicants may be entitled.
Number | Name | Date | Kind |
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1188185 | Krulish | Jun 1916 | A |
2827325 | Pugh | Mar 1958 | A |
3164346 | Bateson | Jan 1965 | A |
3827745 | Pugh | Aug 1974 | A |
4438829 | Waters | Mar 1984 | A |
4883301 | Pugh | Nov 1989 | A |
5074382 | Do | Dec 1991 | A |
5092644 | Melerine | Mar 1992 | A |
5549342 | Donaldson et al. | Aug 1996 | A |
Number | Date | Country | |
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20040217611 A1 | Nov 2004 | US |