KR102343225B1 - Thermal cycle resistant fastening system for refrigerant fitting - Google Patents

Abstract

The block fitting assembly comprises a first block having a first fastener aperture formed therethrough, a second block having a second fastener aperture formed therethrough in axial alignment with the first fastener aperture, and a first fastener aperture. and a fastener extending through the aperture and the second fastener aperture to couple the first block to the second block. The block fitting assembly defines a second fastener aperture in which an inner surface of the second block includes an axially extending non-threaded portion proximate the threaded portion, or wherein the fastener has an outer diameter less than a minor thread diameter of the threaded portion of the fastener. a thermal expansion compliant characteristic in the form of at least one of a neck portion having a

Description

THERMAL CYCLE RESISTANT FASTENING SYSTEM FOR REFRIGERANT FITTING}

This patent application claims priority to U.S. Provisional Patent Application Serial No. 62/716,619, filed on August 9, 2018, the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION The present invention relates to a block fitting assembly for a vehicle air conditioning system, and more particularly, to a block fitting assembly comprising a fastening assembly that allows its flexibility or resilience while maintaining a desired clamping force during thermal cycling of the block fitting assembly.

In assembly line manufacturing of a vehicle, the line fittings of the air conditioning system may be securely fastened using a power nut driver rather than using a torque wrench. For this reason, peanut or block type fittings are often used and assembled using electric (DC) torque tools.

Several refrigerants are used in vehicle air conditioning systems, such as R12, R134a, R1234F and R744 (CO _{2 ).} However, there are environmental concerns. Eventually, laws were passed by several government agencies in the United States and the European Union, requiring, for example, that air conditioning systems operate substantially free of refrigerant leakage or penetration.

Automotive refrigerant components used in CO ₂ air conditioning systems must be tested according to VDA DIN SPEC 74102 (8/2015) of the German Automobile Industry Association (Verband der Automobilindustrie - VDA) and the German Standards Organization (Deutsches Institut fur Normung - DIN) , this includes pressure and temperature cycling checks. Many refrigerant fitting designs fail this test due to severe thermal expansion gradients occurring within the refrigerant block fittings and the associated fasteners used to join them. Many refrigerant block fittings and fasteners are constructed from different materials such as aluminum, stainless steel, and low carbon steel alloys. Accordingly, the coefficient of thermal expansion also differs between different components, such as between fasteners associated with cooperating block fittings.

Block type fitting assemblies generally include a male block configured to mate with a female block. The male and female blocks include aligned apertures for penetratingly receiving a threaded fastener, such as a stud or bolt, wherein the threaded fastener also provides sufficient compressive force to be applied to the sealing element of the block fitting assembly while also providing the male block. is configured to couple to the arm block. The problem posed by the use of threaded fasteners is how the fastener's external threads are substantially confined in the axial direction of the fastener when engaged with internal threads formed in one or both of the cooperating apertures formed through the block. is about As a result, the portion of the threaded fastener that engages the threads of the block may not be thermally expandable or contractible in a desired manner relative to the remainder of the block fitting assembly. If a threaded fastener cannot thermally expand or contract relative to the block or nut in the desired manner, clamping forces that exist between the blocks exist between the block, threaded fastener, and potentially a nut or similar structure used with the threaded fastener. The variable thermal expansion rate may lead to a decreasing situation. This reduction in the clamping force applied to the corresponding sealing element of the block fitting assembly may result in unwanted leakage therefrom.

Accordingly, there has been a continuing need for a block fitting assembly that includes a fastening assembly that allows its flexibility or resilience while maintaining a desired clamping force in response to a thermal load cycling.

Consistent with the present disclosure, it has been surprisingly found a block fitting assembly having a fastening assembly that allows its flexibility or resilience while maintaining a desired clamping force during thermal load cycling.

In one embodiment of the present invention, a block fitting assembly comprises a first block having a first fastener aperture formed therethrough, and a second block having a second fastener aperture formed therethrough in axial alignment with the first fastener aperture. two blocks, and a fastener extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block. An inner surface of the second block defining a second fastener aperture includes a non-threaded portion arranged proximate the first fastener aperture and a threaded portion arranged proximate the non-threaded portion. The fastener further includes a first threaded portion configured to engage a threaded portion of the second fastener aperture.

In another embodiment of the present invention, a block fitting assembly comprises a first block having a first fastener aperture formed therethrough, and a second block having a second fastener aperture formed therethrough in axial alignment with the first fastener aperture. two blocks, and a fastener extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block. The fastener includes a threaded portion and a necked portion. The neck portion has an outer diameter that is less than a minor thread diameter of the threaded portion.

In another embodiment of the present invention, a block fitting assembly includes a first block having a first fastener aperture formed therethrough, a second fastener aperture formed therethrough in axial alignment with the first fastener aperture; a second block, an internally threaded nut configured to engage a face of the first block facing away from the second block, and extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block I include a fastener to say. The second fastener aperture includes a non-threaded portion arranged proximate to the first fastener aperture and a threaded portion arranged proximate to the non-threaded portion. The fastener includes a first threaded portion configured to engage a threaded portion of the second fastener aperture and a second threaded portion configured to engage a nut. The fastener further includes a neck portion arranged between the first threaded portion and the second threaded portion and having an outer diameter less than a minor thread diameter of the first threaded portion.

The above and other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of preferred embodiments when considered with reference to the accompanying drawings.
1 is a cross-sectional elevational view of a block fitting assembly having an increased free length fastener in accordance with an embodiment of the present invention;
2 is a cross-sectional elevational view of a block fitting assembly having a fastener having a neck portion in accordance with another embodiment of the present invention.
3 is a cross-sectional elevational view of a block fitting assembly having both a neck portion and a fastener having an increased free length in accordance with another embodiment of the present invention.
4 is a cross-sectional elevational view of a block fitting assembly having a press-fitting connection between a fastener and a corresponding block in accordance with another embodiment of the present invention;
5A-5D illustrate several different cross-sectional shapes of fasteners taken through section line 5-5 of FIG. 4 .

The following detailed description and accompanying drawings describe and illustrate several embodiments of the present invention. These detailed description and drawings serve to enable those skilled in the art to make and use the present invention, but are not intended to limit the scope of the present invention in any way. In the disclosed method, the sequence of steps presented is exemplary in nature and thus is not required or critical.

1 illustrates a block fitting assembly 10 according to an embodiment of the present invention. The block fitting assembly 10 is configured for fluidly coupling two fluid transport components of an associated fluid system. A related fluid system may be, by way of non-limiting example, a refrigerant circuit in a heating, ventilation and air conditioning (HVAC) system of an automobile or a coolant circuit associated with a drive mechanism or energy source in an automobile. The block fitting assembly 10 generally includes a male block 20 , a female block 40 , a fastener assembly 60 and a sealing element 80 .

The fastener assembly 60 includes an externally threaded stud 62 and an internally threaded nut 64 . The stud 62 includes a first threaded portion 65 near a first end of the stud 62 , a second threaded portion 66 near a second opposite end of the stud 62 , and a first threaded portion 65 . ) and a stop feature 68 formed intermediate the second threaded portion 66 . In the provided embodiment, the first threaded portion 65 and the second threaded portion 66 are shown to have the same construction of threads, the threads of the first threaded part 65 and the threads of the second threaded part 66 being shown. has the same pitch, angle, depth and pitch diameter. 1 , however, the first threaded portion 65 optionally has a reduced thread diameter compared to the second threaded portion 66 due to the direction of entry of the stud 62 through the blocks 20 , 40 , and , it is clear that it may include threads with altered pitch, angle or depth. Hereinafter, it is assumed that the first threaded portion 65 and the second threaded portion 66 comprise threads of the same structure which are spaced apart from each other in the axial direction by including the stop feature 68 .

The external thread of stud 62 includes an alternating pattern of roots and crests, wherein the minimum thread diameter of each of the threaded portions 65 and 66 (hereinafter referred to as "minor thread diameter") is the root of each Whereas the maximum thread diameter of each of the threaded portions 65 and 66 (hereinafter referred to as the “major thread diameter”) is measured for each crest. At least one diametrically opposite portion of the stop feature 68 has minor threads in the threaded portions 65 , 66 to prevent passage of the stop feature 68 past the corresponding internally threaded surface of the arm block 40 . includes an outer diameter greater than the diameter. The stop feature 68 may further include an outer surface having a hexagonal or octagonal cross-sectional shape configured to cooperate with a corresponding tool to rotate the stud 62 , as desired. The stop feature 68 helps to set the depth of entry of the stud 62 into the male block 20 when the stud 62 travels in a downward direction from the perspective view of FIG. 1 . However, also looking at Fig. 1, as long as the stud 62 is inserted axially to the desired extent suitable to receive the nut 64 beyond its end, the stud 62 has a stopping characteristic without necessarily departing from the scope of the present invention. It will be appreciated that in the absence of part 68 it may also be presented with only a single continuous threaded portion.

The internal threads of the nut 64 are configured to mate with the external threads of the stud 62 , and more specifically, the external threads of the second threaded portion 66 . As such, the minor thread diameter, major thread diameter, pitch, angle and depth of the threads of the nut 64 are selected to correspond to those of the threads of the stud 62 . When the nut 64 is used to compress the male block 20 towards the female block 40, the nut 64 may, as desired, use a corresponding washer (not shown) or It may be presented in cooperation with a similar structure.

The annular sealing element 80 is received between the male block 20 and the female block 40 and is configured to be compressed. In the illustrated embodiment, the sealing element 80 includes a metal portion 81 surrounded by an elastomeric portion 82 . However, the sealing element 80 can be made of any material or materials having the desired characteristics of deformability and chemical resistance, including the use of only metal, only elastomers, or combinations thereof as disclosed in FIG. 1 . It can also be prepared from combinations.

The male block 20 is formed of a body 21 having a tubular ridge 22 . The raised portion 22 includes a steering feature 23 surrounding the first seal engagement surface 24 axially retracted from the piloting feature 23 . The first seal engagement surface 24 extends primarily in a radial direction of the raised portion 22 and may include one or more teeth or grooves suitable for engagement with the annular seal element 80 . A first fluid aperture 25 extends transversely from the first seal engagement surface 24 and through the body 21 . The first fluid aperture 25 is configured to receive a fluid conveyed through the block fitting assembly 10 . In some embodiments, the first fluid aperture 25 receives a conduit or tube (not shown) for carrying fluid from other components of the fluid system utilizing the block fitting assembly 10 . is configured to In other embodiments, the male block 20 may be formed integrally with a component of a fluid system without intermediate lengths of conduit or tubing, the first fluid aperture 25 being the fluid carrying portion of the associated component. is directly induced into

Male block 20 also includes a first fastener aperture 26 formed therethrough. More specifically, the first fastener aperture 26 extends from the first side 27 of the male block 20 towards the female block 40 through the body 21 of the male block 20 . (27) extends to the second face 28 of the male block 20 formed on the opposite side. The first fastener aperture 26 extends axially in a direction parallel to the axial direction of the first fluid aperture 25 . The first fastener aperture 26 is cylindrical in shape and lacks any form of internal thread suitable for engagement with any of the threaded portions 65 , 66 of the stud 62 . The first fastener aperture 26 is thus formed to include an inner diameter that is greater than the major thread diameter of either of the threaded portions 65 and 66, such that the stud ( 62) is allowed to pass.

In the embodiment provided, the leverage heel 30 projects from the end of the body 21 opposite the end of the body 21 having the raised portion 22 projecting from the body 21 . The leverage heel 30 projects away from the first face 27 of the male block 20 in a direction parallel to the axial direction of the first fastener aperture 26 and is disposed parallel to the first face 27 , and an engagement surface 32 spaced therefrom. The leveraged heel 30 leverages the clamping force generated by the fastener assembly 60 to increase the compressive force applied to the sealing element 80 when compressed between the male block 20 and the female block 40 . make it Although the leverage heel 30 is shown and described as protruding from the male block 20 , one of ordinary skill in the art will appreciate that the leverage heel 30 may alternatively be symmetrical from the arm block 40 without departing from the scope of the present invention. It should be understood that it may protrude in a mirrored fashion.

The female block 40 is formed of a body 41 having a recessed portion 42 configured to receive the raised portion 22 of the male block 20 . The recessed portion 42 defines an annular second seal engagement surface 44 extending primarily in a radial direction of the recessed portion 42 . The second seal engagement surface 44 includes one or more teeth or grooves suitable for engagement with the annular sealing element 80 , and is symmetrical in form and construction with the first seal engagement surface 24 of the male block 20 . it may be A second fluid aperture 45 extends laterally from the second seal engagement surface 44 and through the body 41 . The second fluid aperture 45 is configured to receive the same fluid carried through the first fluid aperture 25 of the male block 20 . In some embodiments, the second fluid aperture 45 is configured to receive a conduit or tubing (not shown) for carrying fluid from other components of the fluid system utilizing the block fitting assembly 10 . In other embodiments, the arm block 40 may be formed integrally with a component of a fluid system without intermediate lengths of conduit or tubing, the second fluid aperture 45 being the fluid carrying portion of the associated component. is led directly to

The arm block 40 also includes a second fastener aperture 46 formed therethrough. More specifically, the second fastener aperture 46 extends from the first side 47 of the female block 40 towards the male block 20 through the body 41 of the female block 40 . (47) extends to the second face (48) of the arm block (40) formed on the opposite side. The second fastener aperture 46 axially extends in a direction parallel to the axial direction of the second fluid aperture 45 . A second fastener aperture 46 is formed in the female block 40 at a position to place the second fastener aperture 46 in axial alignment with the first fastener aperture of the male block 20 to form a fastener aperture 26 . , 46) are arranged concentrically. The second fastener aperture 46 is axially spaced apart from the first fastener aperture 26 by a gap 35 formed by the presence of a leverage heel 30 adjacent the fastener apertures 26 , 46 . The first fastener aperture 26 , the gap 35 and the second fastener aperture 46 cooperate to form a single, coextensible aperture which is formed in the assembled male and female blocks 20 , 40 . go through the whole

The second fastener aperture 46 is substantially cylindrical in shape, and has a smaller diameter threaded portion 50 intersecting the second face 48 of the arm block 40 and formed adjacent the threaded portion 50 . and is defined by an inner peripheral surface of the arm block 40 that is formed to include a larger diameter non-threaded portion 52 that intersects the first face 47 of the arm block 40 . The threaded portion 50 of the second fastener aperture 46 is internally threaded and includes threads having the necessary structural features to mate with the external threads of the first threaded portion 65 of the stud 62 . do. The threaded portion 50 of the second fastener aperture 46 thus has a major thread diameter substantially equal to the major thread diameter of the first threaded portion 65 of the stud 62 , and the first thread of the stud 62 . and a minor thread diameter substantially equal to the minor thread diameter of portion 65 .

The non-threaded portion 52 of the second fastener aperture 46 is larger than the major thread diameter of the threaded portions 65 , 65 of the stud 62 , and thus the threaded portion of the second fastener aperture 46 . (50) includes an inner diameter that is similarly larger than the diameter of the major thread. The increased inner diameter of the non-threaded portion 52 allows the threaded portions 65 and 66 of the stud 62 to penetrate without providing substantial interference.

The non-threaded portion 52 of the second fastener aperture 46 may be formed as a counter-bore of the threaded portion 50 thereof. In other words, the second fastener aperture 46 may first drill or first drill the cylindrical opening through the arm block 40 having an inner diameter substantially similar to the minor thread diameter of the stud 62 prior to counter-boring the cylindrical opening. It may be otherwise machined such that the non-threaded portion 52 includes an inner diameter greater than the major thread diameter of the threaded portions 65, 66 of the stud 62, and the second fastener aperture 46 ) may be formed by including a corresponding internal thread by subsequently tapping the inner surface of the remaining portion of the originally formed cylindrical opening. The radially extending surface 55 of the arm block 40 is shown connecting the inner circumferential surface of the threaded portion 50 to the inner circumferential surface of the non-threaded portion 52 . The radially extending surface 55 may be formed by the end of the tool performing a counter-boring process on the arm block 40 if desired. Alternatively, a frustoconical surface (not shown) extending annularly and disposed at an angle to the axial direction of the second fastener aperture 46 may be utilized to join the inner circumferential surfaces of the portions 50 , 52 , , may form a tapered steering feature of the second fastener aperture 46 to better position and align the stud 62 . If such a frusto-conical surface is used, this surface may be used to further mount the arm block 40 at the intersection between the threaded portion 50 and the non-threaded portion 52 before or after the aforementioned counter-boring process. It may also be formed by counter-sinking.

The many different components forming the block fitting assembly 10 may in some cases be formed from different materials with variable thermal expansion characteristics. For example, the male block 20 and the female block 40 may be formed of a first material, while the stud 62 and the nut 64 may be formed of a second material different from the first material. Each of the blocks 20 and 40, studs 62 and nut 64 may be formed of any suitable rigid material, and preferably may be formed of a rigid metal material. The described components may be formed of aluminum, stainless steel, or low carbon steel alloys as non-limiting examples. However, it will be apparent to those skilled in the art that the general principles of the present invention may be applied to the block fitting assembly 10 having any combination of materials having different thermal expansion characteristics as desired.

In use, the raised portion 22 of the male block 20 enters the concave portion 42 of the female block 40 , wherein the sealing element 80 engages the first engagement surface 24 and the second engagement surface. Positioned between 44, the first fastener aperture 26 and the second fastener aperture 46 lie in axial alignment. The first threaded portion 65 of the stud 62 then engages the first fastener aperture 26 of the male block 20 before engaging the threads of the threaded portion 50 of the second fastener aperture 46 . ), the gap 35 and the non-threaded portion 52 of the second fastener aperture 46 . Rotating the stud 62 relative to the threaded portion 50 axially advancing the stud 62 until the stop feature 68 of the stud 62 rests adjacent the radially extending surface 55 . , position the stud 62 relative to the second fastener aperture 46 in the axial direction. Nut 64 is then received over second threaded portion 66 of stud 62 and rotated until nut 64 engages second face 28 of male block 20 . Continued rotation of the nut 64 relative to the stud 62 causes the male block 20 to continue to be pulled towards the female block 40 while the leveraged heel 30 is provided to the fastener assembly 60. It helps to apply a compressive force to the compression of the sealing element 80 . The nut 64 is thus rotated relative to the stud 62 until a desired compressive force is applied to the sealing element 80 between the cooperating first seal engagement surface 24 and the second seal engagement surface 44 . .

As shown in FIG. 1 , when the block fitting assembly 10 is in a fully assembled configuration, the stud 62 has a first length 91, a second fastener aperture, in threaded engagement with a nut 64 . The second length 92 and the first length 91 and the second length 2 are arranged in the threaded engagement state with the threaded portion 50 of 46 and the engagement of the corresponding arbitrary shape of the thread is provided. free length 93 . The first length 91 and the second length 92 are formed due to the axial engagement of the internal threads of the nut 64 and the external threads of the stud 62 with the threaded portion 50 and the nut 64 or second fastener. It represents the axially extending portion of the stud 62 that is at least partially restricted from thermally expanding or contracting axially with respect to the threaded portion 50 of the aperture 46 . The free length 93 thus represents the portion of the stud 62 that can thermally expand or contract under deformation when the block fitting assembly 10 experiences varying degrees of thermal expansion in several different components.

The free length 93 is the length of the stud 62 present in the first fastener aperture 26 , the length of the stud 62 present in the gap 35 and the unthreaded length of the second fastener aperture 46 . It includes a combination of the length of studs 62 present in portion 52 . Inclusion of the non-threaded portion 52 in the second fastener aperture 46 , compared to conventional configurations, the block fitting assembly 10 includes a substantially greater free length 93 , wherein the female block The entire aperture formed therethrough is substantially threaded and engages a correspondingly threaded portion of a suitable threaded fastener. Due to the added free length, additional axial expansion or contraction of the stud 62 may occur, allowing greater flexibility or resilience of the fastener assembly 60 while maintaining the required clamp load during thermal load cycling. This lengthening of the free length 93 of the stud 62 is due to the addition of the non-threaded portion 52 to the existing structure upon formation of the threaded second fastener aperture 46 by other means in the block fitting assembly. This is achieved without requiring an increase in the overall package size of (10). The inclusion of the increased free length 93 of the stud 62 may be considered a thermal expansion flexible feature of the disclosed block fitting assembly 10 .

The length of the non-threaded portion 52 of the second fastener aperture 46 may be selected based on expected conditions encountered by the block fitting assembly 10 . For example, the length of the non-threaded portion 52 may be determined based on the expected degree of thermal expansion or contraction experienced by each of the male block 20 , the female block 40 , or any portion of the fastener assembly 60 during thermal load cycling. , and this degree of expansion or contraction is now influenced by the choice of material from which each of the aforementioned components is formed. The length of the non-threaded portion 52 of the second fastener aperture 46 may be selected to “tune” the block fitting assembly 10 accordingly, such that the fastener assembly 60 forms the sealing element 80 . ) can undergo the desired strain when subjected to thermal load cycling without compromising the compressive force applied to it.

The non-threaded portion 52 of the second fastener aperture 46 may be formed to be substantially cylindrical in its entire length, such that its inner surface is parallel to the axial direction of the second fastener aperture 46 . are placed Alternatively, the end of the non-threaded portion 52 that intersects the first face 47 of the arm block 40 may be formed to include a frusto-conical surface to assist in adjusting the stud 62 therein. Also, this frustoconical surface may be formed by a suitable counter-sinking process.

The non-threaded portion 52 of the second fastener aperture 46 can be distinguished from the frustoconical steering feature that may be present in block fittings of the prior art. Specifically, the axial length of the non-threaded portion 52 is greater compared to such a frustoconical steering feature, and in particular, the length of the non-threaded portion 52 will be compared to the diameter and length of the corresponding aperture. it is when The non-threaded portion 52 of the second fastener aperture 46 is, relative to the axial direction of the second fastener aperture 46 , 0.1 of the diameter of the major thread of the first threaded portion 65 of the stud 62 . It may be selected to have a length in the range of from to 1.5 times. For example, in the illustrated embodiment, the unthreaded portion 52 is 1.5 times greater in length than the major thread diameter of the first threaded portion 65 of the stud 62 , such that the unthreaded portion 52 is the second axially extending approximately 45% of the total length of fastener aperture 46 . However, as noted above, the non-threaded portion 52 of the second fastener aperture 46 is dependent on the material selected to form the block fitting assembly 10 and the expected temperature encountered by the block fitting assembly 10 . and any desired length suitable to achieve a desired degree of thermal expansion or contraction of the stud 62 depending on the pressure conditions.

2 illustrates a block fitting assembly 110 according to another embodiment of the present invention. The block fitting assembly 110 includes a male block 20 and a nut 64 respectively identical to the male block and nut of the block fitting assembly 10 . The block fitting assembly 110 differs from the block fitting assembly 10 by including a modified stud 162 and a modified second fastener aperture 146 that is otherwise formed in the same arm block 40 and thus , the discussion that follows is limited to the specific structure of stud 162 and second fastener aperture 146 .

The second fastener aperture 146 of the block fitting assembly 110 is closed by the absence of an axially extending non-threaded portion for extending the free length of the stud 162 . It is different from the fastener aperture 46 . Instead, the entire second fastener aperture 146 is internally threaded and configured to engage a corresponding external thread of the stud 162 .

The stud 162 has a first threaded portion 165 at one end thereof, a detent feature 168 proximate the first threaded portion 165 , a neck portion 171 proximate the detent feature 168 , and the stud. and a second threaded portion 166 proximate the neck portion 171 at the second end of 162 . The first threaded portion 165 includes an external thread configured to mate with an internal thread of the second fastener aperture 46 , while the second threaded portion 166 mates with an internal thread of the nut 64 . and an external thread configured to achieve. The stop feature 168 has an outer diameter greater than the minor thread diameter of the first threaded portion 165 of the stud 162 so that the stop feature 168 engages the first threaded portion 166 with the second fastener aperture ( The axial position of the stud 162 when engaged with the first face 47 of the arm block 40 during threading in 146 .

The neck portion 171 of the stud 162 includes an outer diameter that is less than the minor thread diameter of any of the threaded portions 165 , 166 of the stud 162 . For example, the outer diameter of the neck portion 171 may be selected to be between 0.5 and 0.9 times the diameter of the major threads of the first threaded portion 165 as desired. The neck portion 171 includes a reduced outer diameter to achieve an effect similar to the increased free length 93 of the stud 62 as shown in FIG. Allows for greater flexibility and resilience of the stud 162 intermediate the threaded portions 165 , 166 to achieve without requiring additional machining of the second fastener aperture 146 . The neck portion of the stud 162 effectively increases the ability of the stud 162 to expand or contract under deformation without increasing the overall package size of the block fitting assembly 110 . The inclusion of the neck portion 171 may thus be referred to as the thermal expansion flexible feature of the block fitting assembly 110 .

The length of the neck portion 171 of the stud 162 may also be selected to provide the desired elasticity and flexibility to the stud 162 intermediate the threaded portions 165 and 166 thereof. As such, only a portion or all of the stud 162 arranged intermediate the threaded portions 165 , 166 may be formed to include a reduced outer diameter in accordance with the expected operating conditions of the block fitting assembly 210 , such that the stud 162 . may be allowed to be tuned to include the desired thermal expansion characteristics. 2, the neck portion 171 extends axially for a length greater than half the length of the first fastener aperture 26, although alternative axial lengths do not depart from the scope of the present invention. If not, it may be used. If an alternative means of axial positioning of the stud 162 is used, the stud 162 may be formed from a member of the disclosed stop feature 168 such that between the threaded portions 165 and 166 as desired. It is also possible to make the neck portion 171 longer. Neck portion 171 may also include different axially extending portions having different outer diameters as desired, to further tune the thermal expansion characteristics of stud 162 .

3 illustrates a block fitting assembly 210 according to another embodiment of the present invention. The block fitting assembly 210 is substantially identical in construction to the block fitting assembly 10 disclosed in FIG. 1, except for the use of modified studs 262, utilizing a combination of the thermal expansion flexible properties described above; Accordingly, the discussion below is limited to the structure of the stud 262 .

Stud 262 is substantially similar in structure to stud 162 , including first threaded portion 265 , detent feature 268 proximate first threaded portion 265 , and neck proximate detent feature 268 . portion 271 and a second threaded portion 266 proximate the neck portion 271 . The stud 262 is thus configured such that when the stud 262 is in the position shown in FIG. 3 , the neck portion 271 of the stud 262 engages the first fastener aperture 26 of the male block 20 and the female block. Substantially similar to stud 162 , except that it is elongated to extend over a portion of each of the second fastener apertures 46 at 40 .

The stud 262 thus includes both a reduced outer diameter and an increased axial free length intermediate the threaded portions 265 and 266 of the stud 262 for each of the reasons previously discussed with reference to the block fitting assemblies 10 and 110 respectively. ) promotes increased elasticity and flexibility. The block fitting assembly 210 is therefore configured by changing the length or outer diameter of the neck portion 271 of the stud 262 or the length of the non-threaded portion 52 of the second fastener aperture 46 of the arm block 40 . can be tuned by any one of by changing

4 illustrates a block fitting assembly 310 according to another embodiment of the present invention. Block fitting assembly 310 is substantially identical to block fitting assembly 10 except for the use of modified second fastener apertures 346 and modified studs 362 of otherwise identical female block 40 . Therefore, the discussion hereinafter is limited to the structure of the stud 362 and the second fastener aperture 346 .

The stud 362 has a threaded portion 365 at one end thereof, a neck portion 371 proximate the threaded portion 365, a press-fitting portion 372 proximate the neck portion 371, and a press-fitting portion ( 372 ) and a nearby head 375 . The threaded portion 365 is configured to engage the threads of the nut 64 and includes a thread having a major thread diameter less than the inner diameter of the first fastener aperture 26 . Neck portion 371 is cylindrical in shape and includes an outer diameter that is less than the minor thread diameter of threaded portion 365 . The head 375 defines an annular surface configured to engage the second face 48 of the arm block 40 surrounding the second fastener aperture 346 .

The second fastener aperture 346 is defined by the inner circumferential surface of the arm block 40 and includes a cylindrical portion 356 intersecting the first face 47 of the arm block 40 and the second face 48 thereof. and intersecting receiving portions 358 . Cylindrical portion 356 includes an inner diameter that is greater than a major thread diameter of threaded portion 365 , and may include the same inner diameter as first fastener aperture 26 .

The receiving portion 358 is a second fastener having a cross-sectional shape taken perpendicular to the axial direction of the second fastener aperture 346 corresponding to the cross-sectional shape of the outer surface of the press-fitting portion 372 of the stud 362 . and an inner circumferential surface defining an aperture 346 . More specifically, the press-fitting portion 372 of the stud 362 is such that the degree of frictional interference desired for axial entry into the receiving portion 358 of the press-fitting portion 372 defines the receiving portion 358 . It may include substantially the same shape while occupying a greater cross-sectional area than the receiving portion 358 in such a way that it resides between the inner circumferential surface and the press-fitting portion 372 .

5A-5D illustrate several other exemplary cross-sectional shapes used in the interaction between the press-fitting portion 372 and the receiving portion 358, each of the disclosed shapes being non-circular and having a second stud attachment. It is configured to prevent undesired rotation of stud 362 when received in perforator 346 . For example, FIG. 5A includes other substantially circular shapes with splines extending radially outward, FIG. 5B includes a substantially square shape, FIG. 5C includes a substantially elliptical shape, and FIG. 5D includes a substantially circular shape. Includes triangular shapes. In each figure, dashed line 380 represents the circumferential shape of the major thread diameter of threaded portion 365 , such that a selected cross-section of receiving portion 358 when stud 362 is fully received in fastener apertures 26 , 346 . Each of the shapes illustrates that the threaded portion 365 of the stud 362 should receive therethrough.

Block fitting assembly 310 includes threaded portion 365 of stud 362 until press-fitting portion 372 of stud 362 meets receiving portion 358 into receiving portion 358, cylindrical portion ( 356) and by passing it through the first fastener aperture 26. The press-fitting portion 372 is then press-fitted until the head 375 engages the second face 48 of the arm block 40 . Nut 64 is then rotated relative to threaded portion 365 of stud 362 until a desired clamping force is applied to blocks 20 , 40 .

As shown in FIG. 4 , stud 362 has a greater free length 393 with substantially no axial interference with the second component compared to block fitting assemblies 10 , 110 , 210 described herein. ) advantageously. A free length 393 extends between the nut 64 and the head 375 of the stud 362 , and includes a receiving portion 358 of the second fastener aperture 346 . Although the press-fitting portion 372 is frictionally engaged with the inner surface of the second fastener aperture 346 along the receiving portion 358 , the press-fitting connection may be formed by an intervening radially extending structure such as an engaging thread. Absence does not necessarily prevent axial expansion or contraction of the press-fitting portion 372 relative to the receiving portion 358 .

In a manner similar to block fitting assembly 210 , block fitting assembly 310 thereby increases both free length 393 of stud 362 while also providing a reduced diameter neck portion 371 therebetween. It includes two different thermal expansion flexible properties. The block fitting assembly 310 may be tuned accordingly by varying any of the disclosed features of each of the disclosed thermal expansion flexible features as desired.

Those of ordinary skill in the art should appreciate that the block fitting assemblies 10, 110, 210, 310 disclosed herein may be modified in many respects without necessarily departing from the scope of the present invention. For example, the disclosed fastener apertures may be formed in an opposing manner for cooperating male and female blocks without necessarily changing the manner of operation of the disclosed subject matter. Moreover, the disclosed studs 62 , 162 , 262 may be replaced with any suitable fasteners, such as threaded bolts, clamping screws, etc., while still maintaining the same relationship disclosed herein. For example, if a bolt is to be used as a fastener, the head of the bolt may be configured to engage the second face 48 of the arm block 40 to provide axial positioning of the bolt, while the opposite end of the bolt may be It may also be threaded to cooperate with the disclosed nut 64 . As such, the bolt may be formed without any type of detent feature for axial positioning of the bolt as disclosed herein. One of ordinary skill in the art will recognize that further variations and modifications may be made to the disclosed block fitting assembly 10, 110, 210, 310 without departing from the scope of the present invention.

While certain representative embodiments and details have been described for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made thereto without departing from the scope of the invention, which is further set forth in the appended claims.

Claims (20)

A block fitting assembly comprising:
a first block having a first fastener aperture formed therethrough;
a second block having a second fastener aperture formed therethrough to be axially aligned with the first fastener aperture, wherein an inner surface of the second block defining the second fastener aperture comprises the first fastener aperture the second block comprising a non-threaded portion arranged proximate the perch and a threaded portion arranged proximate the non-threaded portion; and
a fastener extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block, wherein the fastener is configured to engage a threaded portion of the second fastener aperture. 1 comprising the fastener comprising a threaded portion;
wherein the first fastener aperture is entirely formed of a non-threaded portion, and the second fastener aperture is partially formed of a non-threaded portion;
The diameter of the first fastener aperture is formed uniformly,
wherein the fastener comprises a detent feature proximate the first threaded portion, the detent feature comprising an outer diameter greater than a minor thread diameter of the threaded portion of the second fastener aperture;
the second block further comprises a surface extending radially from the opening side of the threaded portion;
and the stop feature is supported on the radially extending surface. The block fitting of claim 1 , wherein the inner diameter of the first fastener aperture and the inner diameter of the non-threaded portion of the second fastener aperture are each greater than a major thread diameter of the first threaded portion of the fastener. assembly. delete The block fitting assembly of claim 1 , wherein the fastener includes a second threaded portion configured to engage a nut, the nut engaging a face of the first block facing away from the second block. The block fitting assembly of claim 1 , wherein the axial length of the non-threaded portion of the second fastener aperture is between 10% and 150% of a major thread diameter of the fastener. The block fitting assembly of claim 1 , wherein the fastener further comprises a necked portion having an outer diameter less than a minor thread diameter of a first threaded portion of the fastener. 7. The block fitting assembly of claim 6, wherein the neck portion is at least partially arranged in each of the first fastener aperture and the second fastener aperture. 7. The block fitting assembly of claim 6, wherein the fastener further comprises a second threaded portion configured to engage a nut, and wherein the neck portion is formed intermediate the first and second threaded portions. The block fitting assembly of claim 1 , wherein the first block and the second block are formed from a first material, and the fastener is formed from a second material different from the first material. A block fitting assembly comprising:
a first block having a first fastener aperture formed therethrough;
a second block having a second fastener aperture formed therethrough to be axially aligned with the first fastener aperture; and
a fastener extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block, the fastener comprising a threaded portion and a neck portion, the neck portion including the threaded portion the fastener having an outer diameter less than the minor thread diameter of the portion;
wherein the threaded portion of the fastener comprises a first threaded portion and a second threaded portion;
the inner surface of the second block defining the second fastener aperture comprises a threaded portion configured to engage the first threaded portion of a fastener;
a nut configured to engage the second threaded portion of the fastener, the nut engaging a face of the first block facing away from the second block;
the neck portion is formed between the first threaded portion engaging the second fastener aperture and the second threaded portion engaging the nut;
wherein the first fastener aperture is formed entirely of non-threaded portions and has a constant diameter;
the neck portion of the fastener is arranged proximate the stop feature of the fastener having an outer diameter greater than a minor thread diameter of the threaded portion of the fastener;
the second block further comprises a surface extending radially from the opening side of the threaded portion;
and the stop feature is supported on the radially extending surface. delete delete delete The block fitting assembly of claim 10 , wherein the neck portion is at least partially arranged in each of the first fastener aperture and the second fastener aperture. 11. The block fitting assembly of claim 10, wherein the fastener includes a press-fitting portion configured to be axially press-fitted within a receiving portion of the second fastener aperture. 16. The block fitting assembly of claim 15, wherein the inner surface of the second block defining the receiving portion and the outer surface of the press-fitting portion have substantially the same cross-sectional shape. 17. The block fitting assembly of claim 16, wherein the press-fitting portion is prevented from rotating relative to the receiving portion of the second fastener aperture. 11. The block fitting assembly of claim 10, wherein an outer diameter of the neck portion is between 50% and 90% of a major thread diameter of a threaded portion of the fastener. delete A block fitting assembly comprising:
a first block having a first fastener aperture formed therethrough;
a second block having a second fastener aperture formed therethrough in axial alignment with the first fastener aperture, the second fastener aperture comprising: a non-threaded portion arranged proximate the first fastener aperture; , the second block comprising a threaded portion arranged proximate the non-threaded portion;
an internally threaded nut configured to engage a face of the first block facing away from the second block; and
a fastener extending through the first fastener aperture and the second fastener aperture to couple the first block to the second block, wherein the fastener is configured to engage a threaded portion of the second fastener aperture. a fastener comprising a first threaded portion and a second threaded portion configured to engage the nut, the fastener further comprising a neck portion having an outer diameter less than a minor thread diameter of the first threaded portion;
the neck portion is arranged between the first threaded portion engaging the second fastener aperture and the second threaded portion engaging the nut;
wherein the first fastener aperture is formed entirely of non-threaded portions and has a constant diameter;
wherein the fastener includes a stop feature adjacent the first threaded portion and having an outer diameter greater than a minor thread diameter of the threaded portion of the second fastener aperture;
the second block further comprises a surface extending radially from the opening side of the threaded portion;
and the stop feature is supported on the radially extending surface.

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