The following generally relates to fiber optic based probes, and particularly to fiber optic based probes that can bend around a radius to thermally communicate with a desired location to be measured.
Normally, fiber optic temperature probes are designed to include a solid, rigid, tube shaft having a connector end and a distal end. Existing fiber optic temperature probes include, inserted into the shaft, a solid and rigid fiber optic rod. A sensing element or ‘button’ is attached to the distal end of the shaft, and the fiber optic rod makes contact with the button to determine temperature based on light emitted by the sensing element. Existing probes can also include a spring on the connector end to bias the fiber optic rod into contact with the button.
Recognizing that traditional fiber optic temperature probes have difficulty bending to access a target area or surface in a difficult to reach area, the following provides a flexible temperature probe design that can accommodate a bend radius through which the probe is inserted.
Flexible temperature probes should allow for deformation, such that the probe bends around a tight radius port to make contact with, or thermally communicate with the object that is desired to be measured. A flexible shaft temperature probe has been developed that has a flexible polymer shaft (polytetrafluoroethylene (PTFE) in this example, although other polymers may be substituted depending on the bend radius and operating temperature of the environment) and has a flexible fiber optic bundle replacing the rigid glass rod.
In one aspect, a flexible fiber optic temperature probe is disclosed. The probe includes a plurality of fiber optic elements, and a sensing member. The sensing member has a first and a second end, the first end connected to distal portions of the plurality of fiber optic elements. The probe includes a flexible jacket surrounding the plurality of fiber optic elements and secured to with the sensing member to prevent relative movement between the flexible jacket and the sensing member.
In example embodiments, the first end of the sensing member is adhesively fixed to the distal portions of the of the plurality of fiber optic elements.
In example embodiments, the flexible fiber optic temperature probe further includes a member for engaging an opening of a channel, the member being a channel length distance from the sensing member. The aforementioned member is secured to prevent relative movement between the flexible jacket and the sensing member.
In example embodiments, a length of the sensing member enables the sensing member to pass through a minimum radius of a channel having one or more bends.
In example embodiments, a thickness of the sensing member enables the sensing member to pass through a minimum radius of a channel having one or more bends.
In example embodiments, the sensing member further includes a first portion having the first and the second end, and a tip portion having a sensing element, the tip portion secured to the second end. In example embodiments, the tip portion is removably secured to the second end.
In example embodiments, the flexible jacket is engaged with the sensing member by one or more of a friction fit, crimping, an overmold or a dip coat/potting compound, or an adhesive connection.
In example embodiments, the flexible jacket is at least in part disposed between an exterior portion and an interior portion of the sensing member, and the flexible jacket is crimped to one or more of the exterior portion or the interior portion. In example embodiments, the interior portion of the sensing member includes a clearance at least in part able to receive the flexible jacket on an exterior surface. In example embodiments, the exterior portion of the sensing member extends further from a distal end of the sensing member than the interior portion, and the exterior portion is crimped with the flexible jacket to at least in part interfere with axial movement of the interior portion relative to the exterior portion.
In another aspect, a method of assembling a flexible fiber optic temperature probe is disclosed. The method includes inserting a plurality of fiber optic elements within a channel defined by a flexible jacket and securing distal portions of the plurality of fiber optic elements to a sensing member. The method includes securing the flexible jacket to the sensing member.
In example embodiments, securing distal portions of the plurality of fiber optic elements to a sensing member further comprises inserting the distal portions of the plurality of fiber optic elements through an interior channel of the sensing member.
In example embodiments, the method further includes securing a member for engaging an opening of the channel a channel length distance from the sensing member.
In example embodiments, the plurality of fiber optic elements are inserted within a channel defined by a flexible jacket subsequent to securing the distal portions of the plurality of fiber optic elements to the sensing member.
In example embodiments, securing the flexible jacket to the sensing member comprises crimping the flexible jacket to one or more of an exterior portion or an interior portion of the sensing member.
In example embodiments, the sensing member includes a first portion and a second portion comprising a sensing element secured to one another, the method further comprising attaching the first portion to the second portion. In example embodiments, the first portion and the second portion are removably attached to one another.
In example embodiments, securing the flexible jacket to the sensing member comprises securing a portion of the flexible jacket to a recessed portion of the sensing member.
In another aspect, an assembly including a temperature sensor is disclosed. The assembly includes a body including a channel having at least one bend, the channel ending at an edge. The assembly includes a temperature probe comprising a plurality of fiber optic elements, a sensing member having a first and a second end, the first end connected to distal portions of the plurality of fiber optic elements, and a flexible jacket surrounding the plurality of fiber optic elements and engaged with the sensing member to prevent relative movement between the flexible jacket and the sensing member. The temperature probe is at least in within the channel and passes through the at least one bend to have the sensing member thermally communicate with the edge.
In example embodiments, the assembly further includes a mechanism to bias the sensing member to contact the edge.
In another aspect, a flexible fiber optic temperature probe is disclosed. The probe includes a bundle of fiber optic elements, and a collar having an internal channel, the collar being secured to end portions of the bundle within the internal channel. The probe includes a sensing member including a first part and a second part, where the first part includes: a channel for receiving the collar, the first part being secured to the collar within the channel; and a projection capable of being secured to adjacent walls. The second part includes a sensing element.
In example embodiments, the first part and the second part are removably attached.
In example embodiments, the first part is adhesively fixed to the collar.
In example embodiments, the projection includes one or more surfaces for laser welding with the adjacent walls.
In example embodiments, at least part of the first part is insertable within a passage defined by the adjacent walls, and the projection prevents another part of the first part from being insertable within the passage.
In yet another aspect, a ferrule and gluing method on the distal end of the tube is disclosed that can allow threading in of the phosphor button. Moreover, there is disclosed a ferrule on the near connector end to provide attachment of the flexible tubing to the connector nut and not cause damage or separation of the flexible tube to the connector.
Additionally, the phosphor can be attached to the fiber with an overmold or dip coat/potting compound.
Embodiments will now be described with reference to the appended drawings wherein:
Hereinafter, it is understood that the terms sensor and probe shall be used interchangeably to at least refer to a device that measures temperature, unless indicated otherwise. Moreover, for ease of reference, the terms sensor and probe shall be understood to mean a flexible temperature probe or sensor, as described herein.
Existing optical temperature sensors are rigid, having a rigid optical rod to contact a sensing element, and possibly including a rigid shell to accommodate the rigid optical rod.
The present disclosure relates to flexible optical probes. The disclosed probe potentially satisfies or alleviates the following concerns which arise where a rigid rod is not used as a medium to transmit the light from the sensor: (1) protection of the medium from external light pollution, or physical damage owing to the external environment, (2) providing a means of ensuring signal continuity notwithstanding installation or access geometry having bends, (3) attaching the medium to the probe tip reliably and without impacting the performance of the probe, and (4) avoiding unnecessarily complex manufacturing or relatively expensive, or relatively unavailable constituent elements.
Turning now to the figures,
The channel 104 includes at least one bend 106 and has a channel length C defined by the distance a probe needs to travel from the opening 108 of the channel 104 to the desired location (e.g., here, the surface 102). It is understood that the shown channel length C is illustrative, and the channel length C includes permutations of a probe travelling the length of the channel 104 other than directly. For example, the channel length C includes channel lengths where the probe has kinks or other types of variations that increase or decrease the length of probe required to contact the desired area.
The bend 106 can be of a variety of different sizes, and include a variety of different features, as will be discussed below. In at least one example embodiment, the body 100 includes multiple bends (not shown), however, for the sake of simplicity, the discussion shall refer to scenarios where a single bend is encountered.
Similarly, as alluded to above, the bend 106 can include one or more features which impede a probe passing through the channel 104. For example, the shown bend 106 includes variations that can obstruct a probe passing through the bend 106. A variety of variations are contemplated by this disclosure. For example, in the shown embodiment, the variation is defined by a single continuous step 110 which expands the channel 104, such that the variation is defined by a diameter D′ that is greater than the diameter D of the channel 104 in regions other than in the variation. A probe passing through the channel 104 could potentially be stopped from passing further into the channel 104 by the steps 110.
Referring now to
The jacket 116 includes a channel into which the plurality of fiber optic elements 118 can be inserted. For example, the jacket 116 includes a channel 154 (
The probe 112 can include a label 126, and a mechanism 127 (e.g., a spring-loaded mechanism) to bias the sensing member 114 towards a surface (e.g., surface 102). The mechanism may be part of a standard straight tip (ST) connector at a connection end of the probe 114.
Also shown in
Referring now to
Referring now to the sensing member 114, properties of the sensing member 114 can be adjusted to facilitate the probe 112 passing through the channel 104. For example, the sensing member 114 can be selected to have a thickness t or height h capable of passing through a diameter D of a smallest bend 106 in a channel 104.
The tip 128 and the ferrule 130 are securable to one another such that the sensing element 140 is in optical communication with the distal ends of the elements 118, as shown. In example embodiments, as shown in
Optionally, as shown in
The tip 128 includes the sensing element 140. The sensing element 140 can be made from a phosphor compound disc, or other material(s) suitable for temperature measurement. In the shown embodiments, the sensing element 140 is disposed within a cavity 142 within the tip 128. The sensing element 140 can be secured to the interior of the tip 128128, for example, by adhesive bonding, or by overmolding, etc.
The exterior profile of the tip 128, for example defined in part by the contour 144 and the distal end contour 146, can be configured or selected based on expected properties of the channel 104 and the bends 106 therein. For example, the sensing member of
Similarly, and in example embodiments, complimentary to the configuration of the tip 128, the ferrule 130 can be configured based on expected properties of the channel 104 and the bends 106 therein. For example, again referring to
Also illustrated in
Referring now to
At block 802, distal portions of the plurality of fiber optic elements 118 are secured to a sensing member 114 (e.g., the ferrule 130 of the sensing member 114). Image 155 of
At block 804, the plurality of fiber optic elements 118 are inserted within a channel (e.g., channel 154) defined by the flexible jacket 116.
At block 806 the flexible jacket 116 is secured to the sensing member 114. For example, as shown in
In example embodiments, similar to the connection between the tip 128 and the ferrule 130, the jacket 116 can be secured to the sensing member 114 via an overmold (e.g., a melt-processable or sintered fluoropolymer) or dip coat/potting compound. Some fluoropolymers like perfluoroalkoxy alkanes (PFA) are melt-processable and PFA could be an alternate material for the jacket 116.
Images 156 show an example process of inserting the plurality of fiber optic elements 118 into the jacket 116, which includes sliding the jacket over the elements 118. In the shown example, the jacket 116 can be secured with a friction fit with the ferrule 130 through the application of force. As discussed above, in at least some example embodiments, the jacket 116 is secured to the ferrule 130 via a combination of one or more of adhesion, crimping, or other means.
It is understood that the disclosure contemplates blocks 802, 804, and 806 occurring in different sequence to the sequence shown in
Referring now to
At block 808, and wherein block 802 included attaching the elements 118 and the jacket 116 to a sensing member 114 without a sensing element (i.e., unassembled), the tip 128 having the sensing element 140 of the sensing member 114 is secured to the ferrule 130, completing assembly of the sensing member 114. In example embodiments, the tip 128 is removably attached to the ferrule 130, for example via a threaded connection, as shown in
At block 810, a member 120 for engaging an opening 118 of a channel 104 a channel length distance from the sensing member 114 is secured to the jacket 116. For example,
It is understood that, while throughout this disclosure the sensing member 114 has been described as being composed of separate parts, one or more of the constituent parts, or the entire sensing member 114, may be a single part. That is, the sensing member 114 can include various unitary combinations of the described constituent parts. For further certainty, the sensing member 114, for example, can be comprised of a unitary tip 128 and ferrule 130.
The sensing element 214 includes a collar (e.g., an inner ferrule 230), a tip 228, and an intermediary part (e.g., an outer ferrule 234). The inner ferrule 230 includes an internal channel 232 for receiving the bundle of fiber optic elements 218. Similar to the ferrule 130, the inner ferrule 230 is secured to end portions of the bundle 218 within the internal channel 232. In at least some example embodiments, the inner ferrule 230 is a part separate from the sensing member 214. For example, the end portions of the bundle 218 can be secured to the inner ferrule 230 (e.g., via gluing) prior to the inner ferrule 230 being secured to the sensing element 214. The inner ferrule 230 can be glass to at least in part address concerns related to bundle 218 optical performance, or to address concerns about heat dissipation, as discussed herein.
In at least one example embodiment, the end portions of the bundle 218 can be secured to the inner ferrule 230, and the inner ferrule 230 is passed through the passage defined by wall 250 to an opening. The inner ferrule 230 is thereafter secured to outer ferrule 234, which itself includes a channel 238 for receiving the inner ferrule 230. The outer ferrule 234 can be a rigid metal part, and the inner ferrule 230 can be secured to the outer ferrule 234 via, for example, glue or other attachment mechanisms. In example embodiments, for example, the inner ferrule 230 and the outer ferrule 234 are secured at a portion 252 of the outer ferrule 234 which is distant from projections (as described herein) of the outer ferrule 234, as said projections may be subject to thermal loading which can potentially adversely impact the securing means. In example embodiments, the outer ferrule 234 at portion 252 includes a funnel configuration to facilitate receiving the inner ferrule 230 into the channel 238.
In at least some example embodiments, the outer ferrule 234 includes one or more projections 236 that are capable of being secured to adjacent walls (e.g., wall 250). The projections 236 can be secured to the adjacent portion of wall 250 by, for example, laser welding of an outer surface of the projection 241 to the adjacent wall portion, generating the heat alluded to earlier, or via gluing, etc. Securing the outer ferrule 234 to the adjacent portion of wall 250 via the projections 236 closes the opening in the wall 250. In this way, the environment within the passage of the wall 250 is isolated from the environment outside of the sensing element 214.
The projections 236 can fit within the passage defined by the wall 250 through which the bundle 218 is passed, or as shown in
The tip 228 can include a sensing element 240, and is secured to the intermediary part 234, so that the sensing element 240 is in optical communication with the distal ends of the bundle 218, as shown. The parts can be secured in a variety of manners. For example, the sensing element 240 and the outer ferrule 234 can be removably attached, via a threaded engagement, or secured via an adhesive, etc. In at least some example embodiments, the sensing element 240 and the outer ferrule 234 form a single unitary part.
Referring now to
At block 1102, the distal portion of the bundle 218 is secured to the inner ferrule 230.
At block 1104, the inner ferrule 230 secured to the sensing element 214.
At block 1106, the sensing element is secured to adjacent walls 250.
Referring now to
At block 1202, the flexible temperature probe 112 that can operate within a bent configuration is provided. The bent configuration can be defined by the smallest bend 106 in a channel 104 into which the probe 112 is being installed.
At block 1204, the sensing member 114 of the temperature probe is passed through a channel (e.g., channel 104) having at least one bend (e.g., bend(s) 106) to have the sensing element 114 thermally communicate with the desired area. In example embodiments, the desired area is a surface (e.g., surface 102).
Passing the probe 112 can include passing the sensing element 114 past any obstructions or variations before insertion into the channel 104. In example embodiments, for example, there is a top plate (not shown) above the opening 118 into the channel 104 shown at the top of the image in
For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those of ordinary skill in the art that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the examples described herein. Also, the description is not to be considered as limiting the scope of the examples described herein.
It will be appreciated that the examples and corresponding diagrams used herein are for illustrative purposes only. Different configurations and terminology can be used without departing from the principles expressed herein. For instance, components and modules can be added, deleted, modified, or arranged with differing connections without departing from these principles.
The steps or operations in the flow charts and diagrams described herein are just for example. There may be many variations to these steps or operations without departing from the principles discussed above. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.
Although the above principles have been described with reference to certain specific examples, various modifications thereof will be apparent to those skilled in the art as outlined in the appended claims.
This application claims priority to U.S. Provisional Patent Application No. 63/201,328 filed on Apr. 23, 2021, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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63201328 | Apr 2021 | US |