Patent Application
20130145607
The present invention relates to tube fittings.
Fittings, couplings, reducers or ferrules, typically refer objects used for fastening or joining other objects, such as two tubes. Fittings used for joining tubes are commonly made of metal and are engaged by a locking mechanism, such as a nut. When fittings join two tubes, one tube mechanically attaches to one end of the fitting and the other tube usually requires a coupling device to secure to the other end of the fitting. Fittings used in aerospace applications also typically require a locking feature to ensure the locking mechanism stays engaged to the fitting and does not unintentionally loosen (due to vibrations, wear or other causes). The locking mechanism can be lockwire. Lockwire is braided wire that can connect to the nut, securing the ferrule to a coupling and/or to another object to ensure that connections stay engaged. An alternative type of locking mechanism includes a nut engaging a coupling device.
A fitting for use with a nut with an internal locking mechanism includes a first tubular portion with a first end and a first outer diameter for connecting to a first object; a second tubular portion with a second end and a second outer diameter for connecting to a second object; a transition portion connecting the first tubular portion and the second tubular portion for fluid communication between the first tubular portion and the second tubular portion; and a plurality of pockets spaced circumferentially around the second tubular portion to engage the internal locking mechanism of the nut.
A method of assembling a fitting for use with a nut with an internal locking mechanism and a fastener includes connecting a first tube to the fitting. The fitting includes a first tubular portion with a first end and a first outer diameter for connecting to a first object, a second tubular portion with a second end and a second outer diameter for connecting to a second object, a plurality of pockets spaced circumferentially around the second end portion to engage the internal locking mechanism of the nut, and a transition portion connecting the first portion to the second portion. The method further includes connecting a second tube to a coupling member with a fastener; connecting the coupling member to the second tubular portion of the fitting; and connecting the nut over the fitting and coupling member so that the internal locking mechanism of the nut engages the plurality of pockets of the fitting and the fastener of the nut engages the fastener of the coupling member to lock the fitting with the first tube to the coupling member with the second tube.
Elbow fitting 10 includes first tubular portion 12, second tubular portion 14 and transition portion 16. First tubular portion 12 includes first end 18 with lip 20 and includes a first taper. Second portion 14 includes second end 22 and a plurality of pockets 24 equally spaced circumferentially around second portion 14. Second portion 14 can have a second taper from transition portion 16 to second end 22.
Fitting 10 can be made of stainless steel, nickel (including alloys), corrosion resistant steels (including ferrous based alloys), titanium (including alloys) or other metals depending on requirements. Fitting 10 can be made by machining, forging, casting or other methods depending on materials used and fitting specifications.
In the embodiment of fitting 10 shown in
Pockets 24 are formed around outer circumference of second portion 14 so they are not affected by transition portion 16 shape or structure or by connection of a tube to first end 20. Pockets 24 can be located a distance from end 22 of second portion 14 to lessen stress levels in second end 22. Size, shape, amount and placement of pockets are dependent on system requirements and can vary. For example, pockets can be larger or smaller than pockets shown. Additionally, alternative embodiments of fitting 10 can include fewer or more pockets.
First tube 25 connects to lip 20 of first end 18 of ferrule 10. First tube 25 can be welded into lip 20 of first end 18. Alternatively, first tube 25 can be brazed or inertia bonded to lip 20 of first end 18. Second tube 26 connects to coupling member 30. This can be a welded, brazed or bonded connection. Nut 32 fits around fitting 10.
As seen in
When first tube 25 is connected to second tube 26 through coupling member 30 and fitting 10, nut 32 holds coupling member 30 and fitting 10 together through threads 40. Engagement mechanism 34 engages pockets 24 of fitting 10 to provide anti-rotation force to nut 32, ensuring that nut 32 stays securely connected through threads 40 and does not loosen or back off. This ensures that first tube 25 stays securely connected to second tube 26.
Through the use of fitting 10 with first portion 12, second portion 14, transition portion 16 and pockets 24 for engagement with engagement mechanism 34 of nut 32, fitting 10 securely joins tubes 25, 26 perpendicularly to each other, allowing fluid communication between the two tubes 25, 26 without requiring the lockwire which prior fittings often needed. As mentioned, prior art fittings, such as ferrules, typically required lockwire to secure the nut and ensure that it did not loosen or back out. The lockwire was attached to the outside of the nut and to another object (coupling member, tube, etc.). This created a system that needed more space and left the lockwire exposed and in danger of breaking. A break in one or more of the braids of the lockwire could leave the tube in danger of disengaging. Additionally, the production of lockwire is costly, due to the need to braid the wires to add strength. The current system eliminates the need to use lockwire by placing a plurality of pockets 24 around the circumference of fitting 10 to be engaged by internal engagement mechanism 34 of nut 32. This internal engagement provides the anti-rotation force to ensure nut 32 does not loosen while eliminating the need for expensive and sometimes hazardous systems using lockwire.
To allow for a smooth retraction of nut 32 from fitting 10, pockets 24 can have a gradual transition. This smooth, gradual transition reduces the amount of force required to pull engagement mechanism 34 from pockets 24, allowing for easier disassembly of tubes.
First tubular portion 44 can include a first taper and can connect to a first tube by welding, brazing, bonding or other means. Second tubular portion 46 can connect to a second tube using a coupling member 30 and nut 32 with internal locking mechanism, as shown in
First tubular portion 62, third tubular portion 66 and fourth tubular portion 68 can connect to tubes by welding, bonding, brazing or other means. Second tubular portion 64 can connect to a tube using a nut 32 with internal locking mechanism and a coupling device 30, as seen in
Transition portion 70 of fitting 60 connects first, third and fourth tubular portions 62, 66, 68 with second tubular portion 64, to allow fluid communication between them. This allows for the connecting of a plurality of tubes or pipes (not shown). Fitting 60 is called a wye fitting because it can connect at least one tube (through a tubular portion, for example first tubular portion 62) with another tube (through another tubular portion, for example, second tubular portion 64) at an angle of up to forty five degrees. This allows for a smooth fluid flow between connecting tubes.
In summary, all of fittings 10, 42 and 60 allow for the connection of a plurality of tubes or pipes by forming one end with circumferentially spaced outer pockets for use with a nut with an internal locking mechanism. The shape and design of transition portion 16, 52 and 70 can allow a variety of tubes to be connected together for a variety of different situations without the need for a lot of external locking mechanisms of past fittings.
Additionally, by forming engagement mechanism 34 internally to the fitting, fittings 10, 42 and 60 can have a similar (if not identical) envelope to prior art fittings and ferrules, allowing for the replacement. This allows fittings 10, 42 and 60 to be able to accommodate current tubes (and coupling members) in use, needing to replace the fitting and nut in the system with fitting 10, 42, 60 or fittings of other shapes not specifically shown here and nut 32. Forming fittings 10, 42 and 60 with a plurality of pockets 24 for engagement also allows for fittings 10, 42 and 60 to be used with a variety of different nuts so long as the nut includes a means for engaging pockets 24.
While the invention has been described in reference to using a nut with an internal locking mechanism with fittings 10, 42 and 60, this is for example purposes only and other types of engagement mechanisms can be used. Specific dimensions, shapes and sizes are given for example purposes only, and can vary depending on system requirements.
While the term fitting is used to refer to the devices in
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
This is a continuation-in-part of U.S. patent application Ser. No. 13/323,972, entitled “Ferrule” filed Dec. 13, 2011 by Murphy et al.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13323972 | Dec 2011 | US |
| Child | 13711148 | US |
