Clip-on anchor device
United States Patent n91 Trobaugh 1 1 CLIP-ON ANCHOR DEVICE [75] Inventor: Arnold G. Trobaugh, Milwaukee.  
 Wis.  
 [73] Assignee: Johnson Service Company,  
 Milwaukee, Wis.  
 [22] Filed: May 8, 1974 [21] Appl. No.: 467,865  
 [52] US. Cl. 24/73 VA; 24/213 C; 248/206 R; 285/194; 285/D1G. 22; 277/189 [51] Int. Cl A44b 22/00 [58] Field of Search 277/189, 188, 186, 166; 285/D1G. 22, 194, 317, 319; 248/206 R;  
 24/213 C, 215. 73 PP, 73 UA [56] References Cited UNITED STATES PATENTS 1.376.389 4/1921 Holmes 24/215 1.771019 8/1930 Wickers 285/194 2.173,?79 9/1939 Francois 285/194 2.2831199 5/1942 Baker 285/194 2,792.976 5/1957 Stewart 285/194 2,823,932 2/1958 Schigut 285/194 2.940.720 6/1960 Birr 24/73 UA 1 1 Apr. 8, 1975 3.222.093 12/1965 Simmons 285/D1G. 22  
 Primary Examiner-Robert Smith Attorney, Agent, or Firm-Johnson, Dienner, Emrich &amp; Wagner [57] ABSTRACT A detachable, clip-on anchor device for use in firmly securing and supporting an object to a stationary wall structure. The anchor device embodies a collapsible resilient, cup-shaped member adapted to sealingly engage one surface of the wall surrounding an opening therethrough. Connected to the cup-shaped member is at least one generally longitudinally extending latch finger having a generally transversely directed latching portion adapted to extend through the wall opening and thereafter selectively engage with an opposite surface of the wall in response to a restoring action effectuated when the cup-shaped member partially returns from a collapsed condition to less collapsed cupshaped condition. In a preferred embodiment, the latch finger includes a guide member which facilitates insertion of the latch finger through the wall opening.  
 12 Claims, 4 Drawing Figures CLIP-ON ANCHOR DEVICE BACKGROUND OF THE INVENTION l. FIELD OF THE INVENTION The present invention relates to a detachable clip-on anchor device adapted to secure and support sensing tubes and the like used in pressure and temperature sensing systems to a wall.  
 2. DESCRIPTION OF THE PRIOR ART It is a conventional practice in the field of use pressure gauges or temperature control devices to measure certain conditions of fluids, such as pressure and temperature, in a fluid system. In measuring local fluid pressure, for instance, the use of a pitot tube is a well known practice. Normally, the pitot tube has one end facing upstream in the fluid to be measured and on opposite end anchored to an opening extending through a conduit wall and in fluid communication with a tube which is similarly anchored to the wall. The accuracy of the measurements provided by such type unit is sensing or measuring low fluid pressures in known devices is dependent, at least in part, upon the provision of a reliable seal about the opening which is used to insert the pitot tube into the stream.  
  The simpler types of prior art anchor devices known in the field which are of the removable type generally do not provide a satisfactory seal. On the other hand, other types of devices which do achieve an acceptable seal are generally of the permanent type and of a relatively complex structure which require extensive preparation in mounting of the devices to the duct wall and frequently require access to both sides of the duct wall to do so. Such access is not always readily available. In addition, such type devices by virtue of their complicated construction and the rather cumbersome and difficult steps to be performed in the installation and removal thereof. are less than satisfactory for many appli cations.  
  By way of specific example, the device disclosed in US. Pat. No. 3,101,205 discloses an anchor cable seal which can be quickly and easily pulled out from a wall. However, as will be apparent from such disclosure, if the wall with which the device is used has a thickness which is less than that which is shown, the seal in all probability would not satisfactorily perform its intended function. While still other prior art devices, such as shown in U.S. Pat. No. 3,240,502, permit a fluid seal if conduit thickness varies, such device does not provide an anchor which can be quickly and easily removed from the wall.  
  The prior art apparently has not provided an anchor device which is of a relatively simple construction, which is quickly and easily attached to and detached from a wall structure, and which also provides a secure and fluid-tight arrangement which is effective to seal the opening regardless of variations in the wall thickness.  
 SUMMARY OF THE INVENTION It is an object of the present invention, therefore, to provide an anchoring device which is easily and conveniently attached to and detached from a stationary structure, such as a fluid carrying duct.  
  It is another object of the present invention to provide a device of such type which provides a seal against the undesired leakage of fluid through the duct wall opening which receives the anchor device by providing a reliable fluid impervious seal thereabout.  
  It is another object of the present invention to provide an anchor device which can be simply and easily pushed into pulled out from the duct wall.  
  It is another object of the present invention to provide a versatile anchor device which can be used on duct walls having various thickness while still maintaining an effective and reliable seal.  
  It is another object of the present invention to provide an anchoring device which can be repeatedly detached without seriously damaging the anchor structure or reducing its effectiveness.  
  It is another object of the present invention to provide a device that uses latch fingers for effecting such a seal arrangement and which exhibits reduced stress concentrations in flexure due to repeated use.  
  In order to accomplish the objects, as aforementioned, there is provided a clip-on, detachable anchor device which is particularly adapted for use in anchoring fluidic pressure sensing tubes or temperature sensitive devices such as charge bulbs or capillary tubes, to a wall of a fluid carrying duct which has an opening with opposed surfaces adjacent the opening through which the sensing device is inserted.  
  The anchoring device, preferably, comprises a generally cup-shaped member having a longitudinally extending neck portion and resilient retaining means. The cup-shaped member includes a convex surface, a concave surface which defines a hollow area. a peripheral portion for selective engagement with one surface of a duct wall, and a passageway extending therethrough having a first aperture which communicates with the concave surface and is adapted to slidably and snugly receive one end of a pitot tube of the like therein. The cup-shaped member, itself, is fabricated from an elastically deformable material which permits resilient bending thereof and includes a neck portion from the con vex surface which has a passageway in communication with the passageway formed in the cup-shaped memher. A second aperture in the neck portion is adapted for suitable connection to another pressure sensing tube.  
  Resilient retaining means extend from the concave surface into the hollow area formed by the cup-shaped member. In a preferred embodiment, the resilient means include a pair of generally longitiudinally extending latch fingers symmetrically arranged relative to each other about the first aperture. Each latch finger includes a generally longitudinally extending segment and a latching portion which extends generally transversely to the longitudinal segments of the finger and which is arranged to be oriented in a radially outward direction relative to the longitudinal axis of the cupshaped member for selective engagement with the interior surface of the duct wall surrounding the opening. To enhance the ability of the latch fingers to be pressed together inwardly, respective recesses are formed in the concave surface adjacent the first aperture for receiving each of the respective longitudinal segments of the latch fingers. Additionally, the material of the cupshaped member is such as to permit movement of the latch fingers relative thereto, to thereby reduce stress concentrations resulting from repeated flexing of the latch fingers. As will be shown, the anchor device may be inserted into detached from the wall by simple and easy pushing and pulling actions, respectively.  
  In a preferred embodiment, the latch fingers of the anchor device include an inclined guide member which extends outwardly therefrom. Each guide member has one end connected adjacent the transverse end of the associated latching finger and a portion which slopes downwardly from said end toward the longitudinal axis of the aperture in the cup-shaped member. The free ends of the guide member are separated relative to each other by a distance which is somewhat less than the outside diameter of the wall opening. Inasmuch as the latch fingers are resilient, upon their insertion into the opening, the free ends of the guide members are caused to move radially inwardly a distance sufficient to permit the latching portions of the fingers to pass therethrough, and to thereafter snap back into a latching position.  
  In use, the anchor device may be attached to the duct wall by merely positioning the resilient latch finger over the opening and thereafter pushing in on the device so that the guide members are inserted through the wall opening and, as aforementioned, are effective to radially inwardly depress the latch fingers so that the latter may freely pass therethrough. After the guide members pass through the wall the latch fingers, as a result of their performed resiliency, are enabled to return to their substantially longitudinal and parallel position.  
  In another mode of attachment, however, the cupshaped member by reason of its resiliency is normally merely squeezed prior to insertion of the latch fingers through the wall opening. This action has the effect of bringing the guide members closer together thereby facilitating an easier insertion or pushing in action for achieving attachment. Such latter type of attachment method is found to be highly desirable in situations wherein the wall opening is relatively small so as to preclude a mere pushing type of attachment action earlier described. Another manner of insertion which may be utilized occurs whenever the cup shaped member is pulled back so as to assume an inverted configuration and the latch fingers are squeezed so as to bring the guide members closer together prior to insertion thereof through the opening. In any event, the attachment of the device by whatever method is accomplished in an extremely easy and reliable manner.  
  After the above insertion action, the cup-shaped member&#39;s peripheral portion will contact the exterior surface of the duct wall and partially collapse from its concave-convex configuration. By reason of its resiliency. it will tend to snap back or return to the original condition and it and the longitudinal neck portion which carries the latch fingers will move outwardly away from the duct wall. This restoring or return action of the cup-shaped member to the earlier mentioned normal condition will be arrested when the latch portion of the fingers firmly engage the inner surface surrounding the wall opening whereby the cup-shaped member only partially returns to its normal condition. As this comes about, the perpheral portion of the cupshaped member will be firmly sealingly pressed against the outer surface of the duct wall to thereby create an effective fluid and dirt impervious seal. Consequently, in one easy motion the anchor device can be simply secured to a duct wall.  
  whenever it is desired to quickly detach the anchor from the duct wall and that is necessary is a simple pulling action be effected which is sufficient. by itself, to  
 move the latch fingers radially inwardly and withdraw the unit from the opening.  
  The above, as well as other objects, features, and advantages of the present invention will become apparent upon a reading of a description of the preferred embodiments of the present invention when viewed in conjunction with the several views of the drawings, wherein like reference numerals indicate like parts:  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the improved device of the present invention as used to firmly secure a pitot tube to a duct or conduit wall;  
  FIG. 2 is a sectional side elevational view of the anchor device shown in FIG. 1;  
  FIG. 3 is a somewhat enlarged side elevational view illustrating the anchor device of the present invention in the folded back position; and  
  FIG. 4 is a perspective end view of the improved anchor device of the present invention.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and, in particular, to FIG. 1, there is shown a portion of a fluidic sensing arrangement in which the improved anchor device 12 of the present invention is shown mounted through an opening in, and in sealing engagement with, a wall 14 ofa duct member 15. Although, the anchor device 12 of the preferred embodiment is described as being used in conjunction with a fluidic sensing arrangement, it is noted that the principles of the present invention permit within its scope, use of the anchor device to firmly support and fasten other objects, such as temperature charge bulbs and capillary tubes presently commercially available from Penn Controls a division of Johnson Service Company, of Milwaukee, Wis., and which may be identified as a Series A 19 type, or Series A 11 type, respectively.  
  The anchor device 12 is shown in FIG. 1 as being firmly secured to wall 14 of duct member 15 which has interior and exterior side surfaces 16 and 18, respectively. The conduit wall 14 is made from any suitable material effective for carrying a fluid medium. An opening 20 of appropriate dimension extends through duct wall 14 to receive a portion of the anchor device 12 as well as the sensing segment of a conventional pitot tube 22. The pitot tube 22 which is of a normally available device of well-known construction is used to sense or measure fluid pressure and velocity within a flowing stream of fluid in the duct member 15. The pitot tube 22 has one end segment 24 facing upstream, as indicated by arrow A, and has an opposite segment 26 extending through opening 20 and the anchor device 12 so as to be in fluid communication with a second fluid pressure sensing tube 28.  
  Pressure sensing tube 28 is adapted to be suitably se cured to one end of the anchor device, as will be more fully described hereinafter. While fluid sensing tube 28 is shown as having one end inserted within the anchor device 12, it is to be understood that other conventional and suitable fastening arrangements can be used within the scope of the present invention The opposite ends of the pressure sensing tube 28 is connected to a pressure gauge (not shown), such as a manometer, which is effective to indicate the fluid pressure sensed within the flowing stream by the pitot tube 22.  
  With reference to FIG. 1 taken in conjunction with FIGS. 2 and 4, an embodiment of the anchor device I2 is shown in detail therein. The anchor device 12, in essential respects, comprises a generally concave-convex or cup-shaped member 30, a longitudinally extending neck projection 32 formed integral with the cupshaped member 30, and resilient retaining means 34, the significance of which will be more particularly described hereinafter. Although the described embodiment of the present invention includes a neck portion which is integral with the cup-shaped member 30, it will be apparent that a cup-shaped member without such a neck portion can also be used.  
  As shown in FIG. 2, the cup-shaped member 30 takes the form of a hollow hemispherical body having a convex surface 36 and a concave surface 38 which defines a hollow area 40. Although a hemispherically shaped member 30 is being described, it is, of course, understood that other configurations can be utilized so long as they remain generally in the form of a concaveconvex member. Cup-shaped member 30 has formed thereon an outer peripheral lip portion 42 which is effective to selectively engage the exterior side 18 ofduct wall 14 for providing both a fluid and dirt impervious sealing engagement therewith. Preferably centrally located within the concave surface 38 is a fluid passageway 44 having a longitudinal axis 46 and at one end thereof a first aperture 48 sized 48 to snugly and slidably receive tube segment 26. A pair of diametrically opposed recesses 50 are formed in a concave surface 38 adjacent first aperture 48 and partially extending along the longitudinal length of passageway 44 away from the concave surface 38. Both the passageway 44 and recesses 50 are in open and continuous communication with each other for reasons that will be hereinafter made apparent.  
  The cup-shaped member 30 is fabricated from any appropriate elastically deformable material which per mits resilient compression thereof. In fact, the cupshaped member 30 is fabricated from any appropriate elastically deformable material which permits resilient compression thereof. In fact, the cup-shaped member 30 should be pliable enough to permit complete inversion or reversal of the configuration. that is, the original concave surface 38 should be flexible enough to form a new convex surface and the original convex surface 36 correspondingly, should form a concave surface (see FIG. 3). The material should also be sufficiently resilient to permit relative movement of the latching means 34 therein, thereby minimizing stress build-up in the latching means resulting from repeated flexures thereof. To this end an elastic material such as silicone rubber or black rubber compound has proven satisfactory in use. Such flexibility is also desired for the purpose of permitting a snapping action, details of which will be more fully hereinafter explained.  
  The passageway 44 is formed to extend along the longitudinal portion of the neck projection 32 which pro trudes rearwardly from the convex surface 36. A second aperture 52 formed at the end of the passageway opposite the first aperture 48 is appropriately dimensioned to receive end 29 of the pressure sensing tube 28. While the above type of connection has been described, it is to be understood, of course, that other conventional suitable fixtures or connections may be used with the anchor device 12 to provide for an ac ceptable fluid connection.  
  As more particularly shown in FIGS. 24, the outer or free ends of resilient retaining means 34 extend into the hollow area 40 formed by concave surface 38. In the preferred embodiment of the invention presently being described, the retaining means 34 is formed by a single member 54 made of a spring-like resilient material having a convoluted portion 56 which encircles the passageway 44 and extends outwardly to provide a pair of longitudinally extending and parallel arranged latch fingers 58. Latch fingers 58 extend substantially along the length of the passageway 48 into the hollow area 40. Convoluted end 56 and each latch finger 58 are em bedded or otherwise suitably secured within neck projection 32 of the cup-shaped member 30. While the retaining means 34 has been disclosed as being made of a single member 54 having a pair of latch fingers 58, it is well within the scope ofthe present invention to have additional latch fingers 58 to provide the desired function.  
  Each latch finger 58 includes a generally straight segment 60, a latching portion 62 and a guide portion or member 64. The straight segments 60 which extend from the convoluted end 56 are substantially parallel to the longitudinal axis 46 of the passageway 44 and pass through recesses 50 which are formed in the concave surface 38 of the cup-shaped member 30. The recesses or slots 50 receive the segment 60 of the latch fingers 58 and permit the latter to move through a greater degree of radial movement than would otherwise be permissible.  
  Each latching portion 62 extends generally transversely to the straight segment 60 in a radially outwardly direction relative to the longitudinal axis 46 for selective engagement with the interior side surlface I6 of the conduit wall 14 when installed, thusly enabling a secure attachment of the anchor device I2 to the duct wall 14.  
  Each guide member 64 associated with a respective latch finger 58 has its free end 66 sloped inwardly from the top of the latching portion 62 toward longitudinal axis 46. Both free ends 66 terminate from each other by a distance which is somewhat less than the diameter for the wall opening 20, thereby permitting ready entry of the free ends 66 into the opening 20 in wall 14. That is, the guide members or portions 64 facilitate an easy and quick insertion of the latch fingers 58 through the opening 20 by reason of the fact that as the sloping portions 64 engage the side of opening 20, during insertion, the fingers are urged radially inwardly, thereby their radially outwardly extending latching portions 62 are enabled to pass through the wall opening. Once the latch fingers 58 have been inserted through the opening 20 the preformed resilience or bias of the fingers cause them to spring back to their generally longitiudinal and parallel position thereby having the latching portions 62 latch into latching engagement with the inner surface 16 of duct wall 14. Although the guide members 64 are disclosed as being associated with the latch fingers 58, anchor device I2 can be provided without such members.  
  In addition, while the latch fingers have been dis closed as being integrally connected by a convoluted end, it is within the scope of the present invention that such latch fingers may be discrete members. each of which may be inserted through paassages extending throughout the cup-shaped member. Of course, in such an arrangement, these fingers would be suitably secured by any of the known conventional manners for securing same.  
  Having thus described the construction of the preferred embodiment of the present invention, its mode of attachment, detachment, and use will be hereinafter described. To attach anchor device 12 to the duct wall l4 having a relatively small opening for purposes of securing fluidic sensing tubes 22 and 28 or the like thereto. the anchor device is pulled back so as to be in a folded or reversed condition, as best shown in FIG. 3, wherein the concave surface 38 becomes a convex surface. Thereafter, the guide members 64 are pushed through the wall opening to cause the straight segments 60 and latching portions 62, by virtue of their resiliency, to be urged together radially inwardly so that passage of the latching portions 62 through the opening is uninhibited. After passage of the latch portions 62 of latch fingers 58 through the opening 20 the fingers return, as aforementioned, to their normal generally longitudinal and parallel position by reason of the resiliency thereof and the latch portion 62 of the fingers 58 are in position for engagement with the interior surface 16 of duct wall 14.  
  At this point in time, the reverse or inverted cupshaped member is manaipulated so that by reason of its deformable nature it will snap-back or return to its original eup-shaped condition (see H6. 2). ln the course of this returning or restoring action, the peripheral sealing lip 42 will firmly engage the exterior side surface [8 and the resilient cup-shaped member will, due to its resiliency, simultaneously urge the neck portion 32 carrying the latch fingers 58 away from the exterior surface 18.  
  Alternately, the resilient cup-shaped member 30 may be squeezed by two fingers to move guide members 64 towards each other and the guide members 64 are then pushed through wall openings 20 and released. With other than very small wall openings the latch fingers 58 can be merely pushed into and through the opening without the necessity of squeezing the cup-shaped member 30.  
  As more clearly depicted in FIG. 1, the restoring action of cup-shaped member 30 is only partially com pleted when the latching portions 62 are brought into firm engagement with interior surface 16. In the above described assembled condition of the anchor device 12, the peripheral lip 142 firmly engages exterior surface 18 and forms a tight sealing contact therewith thereby providing not only a seal impervious against fluid but also against ingress of dirt. Thus, if any variations exist in wall thickness, the restoring action of the cup-shaped member is sufficient to compensate therefor by moving the latching portions 62 until they contact the interior surface 16. Subsequently, of course, the opposite ends 26 of the pitot tube 22 can be conveniently inserted within the first aperture 48. The second aperture 52 can have fitted therein pressure sensing tube 28, whereby the pitot tube 22 and second pressure tube 28 are firmly and sealingly secured or anchored to the duct wall [4.  
  Whenever it is desired to quickly detach the anchor device [2 from the wall 14 having a relatively small opening 1 it is only necessary to provide a simple squeezing pressure on guide members 64 through cupshaped member 30 and pulling on anchor device 12. If relatively large openings occur one merely pulls outwardly without squeezing. In this condition the cupshaped member 30 and latch fingers 58 are manually compressed so that each of their respective latch portions 62 again move radially inwardly together and thereby out of full engagement with the interior surface 16 for return passage through opening 20.  
  It is believed apparent that the foregoing description of construction as well as use of the improved anchor device 12 the attaching and detaching of tubes or the like to a duct wall can be performed in a simple, inex&#39; pensive, and effective manner which improves the measuring opration by preventing against leakage. It should be pointed out that the anchor device 12 can also be used to measure static pressure, by merely having the pitot tube removed. Anchor device 12 can also be used to install temperature sensing bulbs or capillary tubes in duct walls so long as such bulbs or capillary tubes are inserted in place of pitot tube 22.  
  while the particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made thereto without departing from this invention in its broader aspects and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the scope of this invention.  
 The invention claimed is:  
  1. In a detachable anchor device for use in anchoring an object to a stationary structure with an opening and having two opposed surfaces adjacent the opening providing a fluid seal between said structure and said object, said device including a member having a convex surface, a concave surface, and a peripheral portion for selective engagement with one of the two opposed sur faces of said structure, and a passageway extending therethrough for receiving the object to be anchored, said member being made of an elastically deformable material which permits resilient bending thereof, and resilient retaining means extending from said concave surface for insertion through said opening including a generally longitudinally extending segment and a latch portion, said latch portion extending generally transversely to said segment and arranged to be oriented in a direction radially outwardly from the longitudinal axis of said aperture for engagement with the other of the opposed surfaces adjacent the opening, whereby said latch portion firmly and selectively engages the other of the opposed surfaces as said cup-shaped member resiliently presses against said one opposed surface to provide a fluid and dirt impervious sealing engagement therewith.  
  2. A detachable anchor device as found in claim 1 wherein said latch portion has connected thereto a guide member for facilitating entry and passage of said latch portion into and through the opening.  
  3. A detachable anchor device as defined in claim 2 wherein said guide member is attached adjacent a top portion of said latch portion and has a free end thereof inclined downwardly toward said longitudinal axis.  
  4. A detachable anchor device as defined in claim 2 further including a recess means formed in said concave surface adjacent said first aperture and said passageway to be in communication thereweith for receiving said straight segment.  
  5. A detachable anchor device as defined in claim 1 wherein said member is formed of a material which permits relative movement of the retaining means therein upon movement of the latter for reducing stress concentrations in said retaining means.  
  6. A detachable anchor device as defined in claim wherein said cup-shaped member is made of a material which permits relative movement of the retaining means therein upon movement of the latter for reducing stress concentrations in said retaining means.  
  7. In a detachable anchor device adapted for use in anchoring fluidic pressure sensing tubes or the like to a wall of a duct carrying fluid to be sensed and having an opening with opposed surfaces adjacent the opening including a generally cup-shaped member having a convex surface, a concave surface which defines a hollow area, and a peripheral portion for selective engagement with one of the opposed surfaces of the duct wall, said member being made of an elastically deformable material which permits resilient inversion thereof, a resilient projection portion protruding from said convex surface, a longitudinally extending passageway extending through both said projection portion and said cupshaped member, said cup-shaped member having a first aperture at one end thereof communicating with said concave surface and said passageway. and resilient retaining means extending from said concave surface into said hollow area for passage through the opening in the duct wall, said resilient retaining means including at least one generally longitudinally extending segment and one latch portion extending generally transversely to said segment and being arranged in a direction radially outwardly from a longitudinal axis of said first aperture for engagement with the other of the opposed surfaces adjacent the opening, whereby said latch portion firmly and selectively engages the other of the opposed surfaces as said cup-shaped member resiliently presses against said one opposed surface to provide a fluid and dirt impervious sealing engagement therewith.  
  8. A detachable anchor device as defined in claim 7 wherein said resilient retaining means further includes a second generally longitudinally extending segment and a second latch portion extending generally transversely to said second segment and oriented in a direction away from said longitudinal axis, both said first and second segments being generally parallel with each other and radially spaced from said longitudinal axis about said first aperture.  
  9. A detachable anchor device as defined in claim 7 wherein a recess means is formed adjacent said first aperture and said first segment is received therein, where by radial movement of said first segment and said latch portion are facilitated.  
  10. A detachable anchor device as defined in claim 7 wherein said latch portion has a guide member attached thereto for facilitating entry and passage of said latch portion into and through the opening.  
  11. A detachable anchor device as defined in claim 8 wherein both said latch portions have respective guide members attached thereto adjacent a top portion of said latch portions and having a free end thereof inclined downwardly toward said longitudinal axis and terminating at a distance from each other, whereby said free ends are spaced somewhat less in dimension than the opening.  
  12. In a detachable anchor device adapted for use in anchoring fluidic pressure sensing tubes or the like to a wall of a duct for carrying fluid to be sensed having an opening and opposed surfaces adjacent the opening including a generally cup-shaped member having a convex surface, a concave surface which defines a hollow area, a peripheral portion for selective engagement with one of the opposed surfaces, a generally longitudinally extending projection portion integrally formed with and protruding from said convex surface, a longitudinally extending passageway centrally located within said device and extending through said projection and said cup-shaped member having at one end thereof a first aperture in communication with said concave surface and at least a pair of resilient springlike latch fingers secured to and extending from said projection portion and concave surface into said hollow area for passage through the opening, said cup-shaped member and said projection portion being made of an elastically deformable material which permits resilient bending thereof as well as relative movement of said pair of latch fingers therein for purposes of reducing stress concentration in said pair of latch fingers, said pair of latch fingers being generally parallel and longitudinally arranged relative to said neck projection portion and passageway so as to radially arranged relative to said first aperture, each of said latch fingers having a generally longitudinally extending segment, a latch portion and a guide member, said latch portion extending generally transversely to said segments and being arranged to be oriented in a direction radially outwardly from a longitudinal axis of said passageway for selective engagement with the other of the opposed surfaces adjacent the opening, whereby said latch fingers firmly engage the other of the opposed surfaces, and said guide member being attached to a top portion of said latch portion and having a free end thereof sloped downwardly or radially inwardly toward said longitudinal axis, said free ends of said guide member terminating in a distance which is somewhat less than the diameter of the opening.