Patent Application
20220145924
This invention relates to surface features which engage rotating fastener elements.
The increased use of powered tools in the field, particularly impact wrenches, allows relatively large torques to be applied to fasteners with little physical effort on the part of the technician. This confluence of factors has the potential to result in an increase in the rate of bolts being over-torqued, in some cases severely so, leading to damage when those bolts are over-torqued by technicians with high-output impact wrenches. It is therefore thought advantageous if measures could be taken which increase a bolt's resistance to damage when powered tools are used.
The invention concerns, in combination, a platform in contact with a fastener element, the fastener element being rotatable about an axis oriented transversely to the platform. In an example embodiment the platform comprises a base surface. A plurality of raised surfaces project transversely to the base surface for contacting the fastener element. Each raised surface comprises a plateau. Each raised surface is separated from at least an adjacent one of the raised surfaces by a channel positioned therebetween.
By way of example, the fastener element may comprise a threaded nut or a head of a threaded bolt.
In a specific example design, each plateau has a height of 0.060 inches above the base surface, and in practical designs each plateau may have a height ranging from 0.020 inches to 0.1 inches above the base surface. Further by way of example, each plateau has a minimum surface area of 0.010 square inches and in practical designs, each plateau may have a surface area ranging from 0.010 square inches to 0.1 square inches. In certain examples, each plateau has a minimum surface area ranging from 0.020 to 0.075 square inches.
In an example embodiment, at least one of the raised surfaces has a polygonal cross sectional shape. Further by way of example, at least one of the raised surfaces may have a round cross sectional shape. In a practical example embodiment, at least one of the raised surfaces is tapered, the at least one raised surface having a smaller perimeter at the plateau than at the base surface.
In an example embodiment the fastener element is softer than the plurality of raised surfaces. In a specific example, the fastener element may comprise steel and the plurality of raised surfaces may comprise ductile iron.
The invention further encompasses a coupling for joining pipe elements in end to end relation. In a particular example embodiment the coupling comprises a first segment having first and second ends oppositely disposed and a second segment having first and second ends oppositely disposed. A first fastener attaches the first end of the first segment to the first end of the second segment. A second fastener attaches the second end of the first segment to the second end of the second segment such that the segments surround a central space for receiving the pipe elements. First and second connection members are positioned respectively at each of the first and the second ends of each of the first and second segments. In an example embodiment, each connection member comprises a base surface oriented transversely to one of the fasteners. A plurality of raised surfaces project transversely to the base surface and are engageable with the one of the fasteners. Each raised surface comprises a plateau. Each raised surface is separated from at least an adjacent one of the raised surfaces by a channel positioned therebetween. By way of example, the fasteners may comprise a threaded nut engageable with one of the raised surfaces and/or a threaded bolt having a head engageable with one of the raised surfaces.
In a specific example design, each plateau has a height of 0.060 inches above the base surface, and in practical designs each plateau may have a height ranging from 0.020 inches to 0.1 inches above the base surface. Further by way of example, each plateau has a minimum surface area of 0.010 square inches and in practical designs, each plateau may have a surface area ranging from 0.010 square inches to 0.1 square inches. In certain examples, each plateau has a minimum surface area ranging from 0.020 to 0.075 square inches.
In an example embodiment, at least one of the raised surfaces has a polygonal cross sectional shape. Further by way of example, at least one of the raised surfaces may have a round cross sectional shape. In a practical example embodiment, at least one of the raised surfaces is tapered, the at least one raised surface having a smaller perimeter at the plateau than at the base surface.
In an example embodiment the fastener is softer than the plurality of raised surfaces. In a specific example, the fastener may comprise steel and the plurality of raised surfaces may comprise ductile iron. In an example embodiment, the plurality of raised surfaces may be integrally cast with the coupling.
The invention further includes a flange mountable on a pipe element. In an example embodiment the flange comprises a ring having a contact face adapted to interface with a mating flange, and an exposed face arranged oppositely to the contact face. By way of example the exposed face comprises a base surface and a plurality of raised surfaces projecting transversely to the base surface. Each raised surface comprises a plateau, and each raised surface is separated from at least an adjacent one of the raised surfaces by a channel positioned therebetween. In a practical example the plurality of raised surfaces extend around the entire exposed face.
In a specific example design, each plateau has a height of 0.060 inches above the base surface, and in practical designs each plateau may have a height ranging from 0.020 inches to 0.1 inches above the base surface. Further by way of example, each plateau has a minimum surface area of 0.010 square inches and in practical designs, each plateau may have a surface area ranging from 0.010 square inches to 0.1 square inches. In certain examples, each plateau has a minimum surface area ranging from 0.020 to 0.075 square inches.
In an example embodiment, at least one of the raised surfaces has a polygonal cross sectional shape. Further by way of example, at least one of the raised surfaces may have a round cross sectional shape. In a practical example embodiment, at least one of the raised surfaces is tapered, the at least one raised surface having a smaller perimeter at the plateau than at the base surface.
In an example embodiment the fastener is softer than the plurality of raised surfaces. In a specific example, the fastener may comprise steel and the plurality of raised surfaces may comprise ductile iron. In an example embodiment, the plurality of raised surfaces may be integrally cast with the flange.
The invention further encompasses a flange coupling for joining pipe elements. In an example embodiment the flange coupling comprises a first ring having a first contact face and a first exposed face oppositely disposed, and a second ring having a second contact face and a second exposed face oppositely disposed. The second contact face interfaces with the first contact face. A plurality of fasteners extend though the first and second rings. Each of the fasteners comprises at least one rotatable member engaging at least one of the exposed faces of one of the rings. In an example embodiment the at least one exposed face comprises a base surface. A plurality of raised surfaces project transversely to the base surface. Each raised surface comprises a plateau. Each raised surface is separated from at least an adjacent one of the raised surfaces by a channel positioned therebetween.
In an example embodiment the plurality of raised surfaces extend around the entire exposed face. Further by way of example, at least one of the raised surfaces has a polygonal cross sectional shape or a round cross sectional shape. In an example embodiment at least one of the raised surfaces is tapered, the at least one raised surface having a smaller perimeter at the plateau than at the base surface. By way of example, the rotatable member may comprise a threaded nut engageable with at least one of the raised surfaces and/or a threaded bolt having a head engageable with one of the raised surfaces.
In an example embodiment the rotatable member is softer than the plurality of raised surfaces. In a specific example embodiment the fastener may comprise steel and the plurality of raised surfaces may comprise ductile iron. In a specific example embodiment the plurality of raised surfaces are integrally cast with the at least one exposed face.
One aspect of the invention is directed to a combination platform and fastener element. An example combination 10 is shown in
As shown in
First and second connection members 50 and 52 are positioned respectively at each of the first and the second ends (34, 36, 40, 42) of each of the first and second segments 32 and 38. In this example, each connection member 50, 52, comprises the above described base surface 20 oriented transversely to the respective fastener (44 or 46) which passes through the connection members. The raised surfaces 24 project transversely to each base surface 20 and are engageable with the fasteners 44 and 46. As described above with respect to combination 10, each raised surface 24 comprises a plateau 26, and each raised surface is separated from at least an adjacent one of the raised surfaces by a channel 28 positioned therebetween. Consistent with combination 10 described above and shown in
In a practical example of a coupling 31, significant disproportionate increase in torque compared with the associated increase in bolt stress was observed for plateaus 26 having a height of 0.060 inches above the base surface 20 and a minimum surface area of 0.010 square inches, when used with a standard ASME B18.2.2 heavy hex nut of size ½″, made of ASTM A563 carbon steel. For an effective design it is expected that plateau area will generally increase with increasing bearing area of the nut and or bolt, as fastener size increases. For this design, the phenomenon of disproportionate increase in torque was observed directly by increased felt torque when a hand wrench was used to tighten the coupling fasteners. In a test intended to induce bolt failure, when an impact wrench was used it was observed that the time to bolt failure increased by a factor of two when couplings employing the raised features according to the invention were tested against couplings not having the combination 10.
It is expected that effective designs of combinations 10 and 11 according to the invention may be achieved with plateaus 26 having a height above the base surface 20 ranging from 0.020 inches to 0.1 inches, with heights of 0.060 inches expected to be advantageous. Practical designs may also have surface areas ranging from 0.010 square inches to 0.1 square inches, with surface areas ranging from 0.020-0.075 square inches expected to be advantageous. Effective protection of bolts ranging from 0.25 inches to 1 inch in diameter (as well as similar and equivalent metric sizes) is expected to be achieved using combinations such as 10 and 11 according to the invention.
In the example coupling 31, the fastener element 14 (the nut 16) was formed of carbon steel and has a lower surface hardness than the plurality of raised surfaces 24, which were integrally cast with the coupling and formed of ductile iron. It has been observed in the experimental coupling that as increasing torque is applied to the nuts 16, plateaus 26 have a sacrificial nature, and are worn down by nuts 16, with bolt stress increasing significantly after plateaus have been significantly worn down.
A plurality of fasteners 72 extend though the first and second rings 58 and 64. Each fastener 72 comprises at least one rotatable member engaging at least one of the exposed faces 62, 68 of one of the rings 58, 66. In a practical example the rotatable member may comprise a threaded nut 74 or a threaded bolt 76 having a head 78 and may engage both exposed faces 62 and 68.
The exposed faces of the flanges 54 comprise a base surface 20 and a plurality of raised surfaces 24 projecting transversely to the base surface 20 as described above for the platform 12 and the coupling 31. The raised surfaces 24 comprise respective plateaus 26. Each raised surface 26 is separated from at least one adjacent raised surface by a respective channel 28 positioned therebetween. The raised surfaces 24 in this example have polygonal cross sectional shapes, but other shapes, such as the round shapes of
In the example shown in
In the flange coupling 56 the rotatable elements (threaded nuts 74 and/or bolt heads 78) engage and rotate relatively to and forcibly against the plateaus 26 when the coupling 56 is assembled. It is expected that the bolts 76 will experience the phenomenon of disproportionate increase in torque required to tighten the nut 74 or bolt head 78 as compared with the increase in tensile stresses within the bolt 76 upon tightening. This effect is expected to protect the bolt 76 from damage due to over-torqueing for the flange coupling 56.
This application is based upon and claims benefit of priority to U.S. Provisional Application No. 63/112,194, filed Nov. 11, 2020, which application is hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 63112194 | Nov 2020 | US |
