This application relates to a check valve stop and a method of making such a stop.
Check valves are known. Typically, a check valve blocks flow of a fluid through a conduit, until the pressure upstream of the valve overcomes a downstream pressure.
One type of check valve utilizes flapper valves having a central pivot axis and a pair of valve plates which seat on the valve seat in the closed position and contact a stop in the open position. Another type of check valve utilizes a flapper valve having one pivot axis to one side and a valve plate which seats on a valve seat.
When the valve plates opens to allow flow, the movement might be rapid. The valve plate may contact the stop in an opening event with a high force. This can lead to the valve plate or stop being damaged and eventually failing.
A check valve has a valve seat defining an aperture and a seating surface. A stop is fixed in position relative to the valve seat and has a solid portion formed as a single homogeneous component. At least one cavity is sealed within the solid portion and is at least partially filed with a particulate material. The solid portion defines a contact surface. A flapper is moveable between a closed position in which the flapper is sealingly engaged with the sealing surface and an open position in which a contact surface of the flapper is in contact with the stop.
A method is also disclosed.
These and other features may be best understood from the following drawings and specification.
The flapper 32 pivots on a pin 34. Pin 34 allows the flapper 32 to pivot between the closed and open positions. At the open position, the flapper 32 contacts stop 59.
As mentioned above, one type of check valve includes a pair of flapper 32 and 32L. Each have their own fulcrum 33 and 33L pivoting about the pivot pin 34.
As shown in
As shown in
Returning to
The particulate material 114 will dissipate the energy from the contact between the flapper 32 and the stop 59.
There are hollows 212 between the rails 220 and 222. Those hollows are filled with particulate material 214. While only a few hollows 212 are shown filled with particulate material in the
In addition, it should be understood that the hollows may be effectively enclosed and trap the powder. Such hollows could be said to be generally fluidly sealed relative to each other due to the rails 220 and 222. On the other hand, the hollows may be open relative to each other.
Another machine 312 is shown depositing the particulate material 314 into what will become another hollow once the manufacturing has progressed to enclose the location of the particulate material 314. The machines 310 and 312 may be different machines, or may be the same machine.
In one example, the additive manufacturing may be selective laser melting. In such a technique, the machines 310 and 312 are the same machine. The material being deposited to form the solid structure 302 is metal particles which are heated as deposited such that they fuse to underlying layers. A control (316), shown schematically, may be controlled to selectively stop the application of heat to the particle when it is time to form the particles 314. Thus, when metal is deposited to form solid structure 302, the metal particles are heated and fused, and when it becomes time to deposit particulate material 314, the metal particles are not heated. To be clear, selective laser melting is an additive process in which layers of powder (particles) are spread successively. Within a layer, a laser locally melts the particles to from the desired solid. Generally, unfused particles are left entrapped to form the particulate material. In this embodiment, the particulate material 314 and the solid structure 302 are formed of a homogeneous material.
In other additive manufacturing embodiments, additive manufacturing extrusion (such as FFF—Fused filament fabrication, FDM—Fused deposition modeling, or BMD Bound metal deposition) may be utilized. In such methods, a filament is melted into a layer through the machine 310. Then, the machine 312 may be a distinct machine which deposits particulate materials.
In another embodiment, photopolymerization (SLA—Stereolithography apparatus, DLP—Direct light processing, CLIP—Continuous liquid interface production) may be utilized. In these embodiments, a resin is deposited. And a machine cures the resin particles to form a solid portion 312. In these embodiments, the particulate may also be deposited by a distinct machine 312.
Binder jetting (BJ) or material jetting (MJ) (3DP-3D printing, polyjet or multijet) may be utilized. In these embodiments, a layer is spread and a binder or additional material is shot into portions of the layer to form the solid portions. Again, some other machine 312 may then be utilized to deposit the particulate material.
Material Jetting dispenses a photopolymer from hundreds of tiny nozzles in a printhead to build a part layer-by-layer. This allows material jetting operations to deposit build material in a rapid, line-wise fashion compared to other point-wise deposition technologies that follow a path to complete the cross-sectional area of a layer. As the droplets are deposited to build a platform they are cured and solidified using UV light. Material jetting processes require support and this is often printed simultaneously during the build from a dissolvable material that is easily removed during post-processing.
Nano particle jetting (NPJ) uses a liquid, which contains metal nanoparticles or support nanoparticles, loaded into the printer as a cartridge and jetted onto the build tray in extremely thin layers of droplets. High temperatures inside the build envelope cause the liquid to evaporate leaving behind metal parts.
Binder Jetting deposits a binding adhesive agent onto thin layers of powder material. The powder materials are either ceramic-based (for example glass or gypsum) or metal (for example stainless steel). The print head moves over the build platform depositing binder droplets, printing each layer in a similar way 2D printers print ink on paper. When a layer is complete, the powder bed moves downwards and a new layer of powder is spread onto the build area. The process repeats until all parts are complete. After printing, the parts are in a green state and require additional post-processing before they are ready to use.
In the embodiments which utilize a distinct machine 312, the particulate can be formed of a distinct material from the material utilized to form the solid portion 302.
The programming of the control 316 is within the skill of a worker in this art. The additive manufacturing technology is well-developed and a worker of ordinary skill would be able to provide an appropriate program to achieve the method as disclosed above or below.
Of course, other manufacturing techniques might be utilized.
While a particular lattice shape is disclosed in
The lattice structure is formed of rails within the stop to provide additional rigidity to said stop.
A check valve 17/19 under this disclosure could be said to include a valve seat 26 defining an aperture 28 and a seating surface 30. A stop 59/159 is fixed in position relative to the valve seat, and has a solid portion formed as a single homogeneous component. At least one cavity is sealed within the solid portion, and at least partially filled with a particulate material. The solid portion defines a contact surface 15. A flapper 32 is moveable between a closed position, in which the flapper is sealingly engaged with the sealing surface, and an open position, in which a contact surface of the flapper is in contact with the stop.
The particulate material is movable within the at least one cavity to dampen an impact forces generated when the flapper contacts the stop during opening of the check valve. The particulate material is sized and configured to provide damping based on physical characteristics of the check valve, and anticipated impact loads during opening of the check valve. An amount of the particulate material within the at least one cavity is selected to dampen impact loads during opening of the check valve.
A worker of ordinary skill in the art, armed with this disclosure, would be able to select and design the particulate material sizes and configuration, along with the amount of particulate material based upon the aspects as mentioned above.
A method of forming a check valve stop including depositing material layer by layer to form a solid portion of the check valve stop as a single homogeneous component having at least one cavity sealed within the solid portion. The method further includes the step of depositing particulate material within at least one cavity during the layer by layer depositing process.
Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the true scope and content of this disclosure.