JP2537578B2 - Pipe fitting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flareless pipe joint, and more particularly to a pipe joint capable of sealing a flareless pipe to a fitting.

[0002]

BACKGROUND OF THE INVENTION Generally, flareless tubes are connected to a tubular fitting body by a nut and ferrule fitting assembly. In this case, the ferrule is attached to the end of the tube, but the ferrule is provided with a sealing surface having a shape that can match the sealing surface formed on the fitting body, and A seal relationship can be established. For example, U.S. Pat.
Ferrules often have inner edges or inner edges that can be deformed inward by tightening compression nuts to engage the associated tube, as disclosed in US Pat.No. 673 and U.S. Pat. A deformable portion with serrations is provided which forms a metal-to-metal seal relationship with the tube and prevents the tube from axially separating from the fitting.

Flareless pipe joints are often used for pipes made of various materials and having various hardnesses. The seal between the pipe and the pipe joint and the axial force resistance are determined by the ferrule and the pipe. Due to the engagement with the, it is not always possible to obtain a fluid-tight assembly when connecting tubes of relatively hard material or tubes with non-uniform surfaces.
If the initial engagement of the ferrule with the tubing is located adjacent to the initial seal area, vibration and deformation of the tubing may cause normal operation during normal operation, even with the fluid seal assembly initially established. Leakage may occur. Some fittings use structures that have improved overall performance as fittings, but the results are still unsatisfactory and the constructions require expensive manufacturing processes.

US Pat. No. 2,523,135 discloses a pipe fitting using a double ferrule structure in which one ferrule has a wedge-shaped metal-to-metal engagement with the associated tube. To be transformed. This wedge-shaped engagement is excellent for pipe fittings that employ ferrules with cut edges or serrations. This is because a large contact area is created between the tube and the ferrule, which results in a more effective seal and frictional force that can establish an effective grip of the tube.
The outer ferrule has a conical sealing surface that establishes a sealing engagement with a conical sealing surface formed on the fixture body, which requires a laborious and costly machining step. become. Also, the ends of the tube are not structured to be received by the ferrule in a supporting relationship that provides additional resistance to vibration.

In the dual ferrule construction disclosed in US Pat. No. 2,737,403, the end of the tube is received in sealing engagement with a circumferential undercut formed on one ferrule while at the same time the other ferrule is received. Establishes a sealing engagement with the other surface of the tube so that a double seal is formed. The undercut portion flares the end of the tube outward to form a seal for the ferrule.
However, the ferrules and nuts that engage the outer surface of the tube use a vertical contact relationship that does not resist vibration loads, and the structure is abutting shoulders formed on the ferrules and nuts that limit tightening of the nuts. Even if a leak occurs during operation, it cannot be further tightened to stop the leak because it has a section. Also, the sealing surface of the ferrule that engages the sealing surface of the fixture body has a conical shape, which necessitates unnecessary precision machining if the sealing surface is flat.

[0006]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a nut-ferrule type fitting for connecting a flareless tube to a fitting body having a flat sealing surface, which is relatively inexpensive to manufacture and use. SUMMARY OF THE INVENTION It is an object of the present invention to provide a nut-ferrule type pipe joint which is simple, efficient, reliable in operation, and can be used for a wide range of pipe materials having various hardnesses.

Another object of the present invention is a pipe joint using a ferrule-sleeve structure, wherein a circumferential undercut is provided inside the sleeve, and the undercut cuts out the end of the pipe. To provide a tube fitting that expands toward the end to establish a support-locking relationship with the end while the ferrule establishes a wedge metal-to-metal seal engagement with the outer surface of the tube to form a double seal. Especially.

Another object of the present invention is a pipe fitting using a ferrule-sleeve structure actuated by a compression nut, wherein the sleeve is attached to the end of the pipe and the ferrule has a front portion and a rear portion. And the compression nut has an inner cam surface which pushes the ferrule axially forward to engage the sleeve, the front portion of the sleeve engaging the tube and the metal-to-metal seal. It is an object of the present invention to provide a pipe joint configured to mate and deform the ferrule into a bent shape and bend the rear portion of the ferrule radially inward into the pipe to assist in vibration damping.

Another object of the present invention is a pipe joint using a structure consisting of a ferrule, a sleeve and a compression nut, and the structure of the pipe joint does not include means for limiting tightening of the nut. It is an object of the present invention to provide a pipe joint in which the nut is sufficiently tightened to establish a double seal between the joint and the associated pipe to form a fluid tight assembly. Another object of the present invention is a flareless tube joint using a sleeve and a ferrule, wherein a cam surface formed on the sleeve compresses and contracts the ferrule on the tube, the sleeve during compression of the ferrule. An object of the present invention is to provide a flareless pipe joint having a shape capable of limiting expansion and radial deformation of the sleeve and configured to apply a pressing force in the radial direction to the ferrule.

[0010]

DISCLOSURE OF THE INVENTION A pipe joint embodying the present invention has a fitting body having a flat radial surface on which an annular recess is formed. Is an elastic "O" having an axial normal dimension greater than its depth.
Accepts the "ring." The attachment body is provided with a male screw at a position adjacent to the end thereof. The fixture body may be brazed or screwed to a tube or other conduit device connection, or may be permanently fixed.

The sleeve located at the end of the metal tube has an inner undercut portion which is adapted to receive the end portion of the tube and expand outwardly. . The sleeve has a flat radial surface that can engage the sealing surface and "O-ring" of the fitting. The sleeve also includes an inner annular conical cam surface that rests on and engages the ferrule and the outer tapered surface to form a radially inflatable gap. . The sleeve has a cantilevered end that is deformed radially outward when the ferrule is compressed to serve to maintain a radial pressing force against the ferrule. To do.

The ferrule has an inner diameter slightly larger than the diameter of the tube. The ferrule also includes a rear portion and a front portion extending toward the fixture body. The outer tapered surface formed on the ferrule engages with the cam surface of the sleeve at various angles, and the compression nut is screwed onto the fixture body, thereby deforming the front portion of the ferrule and pipe. And wedge-shaped metal-to-metal seals. The tapered surface of the ferrule has a much smaller angle than the inner cam surface of the sleeve,
The ferrule is designed to bend inward when the fitting is assembled. This bending action creates a compressive force within the fixture body that absorbs vibrations and reliably supports the tube at a location remote from the location of the primary seal. The nut has an inward annular conical cam surface which, when the nut is rotated in the tightening direction, causes a convex abutment surface formed on the ferrule adjacent to the rear of the ferrule. And push the ferrule axially forward and radially inward to engage the outer surface of the ferrule with the cam surface of the sleeve. This wedge-shaped engagement pushes the end of the tube axially forward into the undercut portion of the sleeve, causing the end of the tube to expand outwardly and lock the connection between the tube and sleeve. Is established to prevent the tube end from being crushed. Also, the inner cam surface of the nut causes the rear of the ferrule to be pushed inward into the tube to bend the ferrule. Therefore, vibration damping is assisted, and the rear end of the ferrule is pressed so as to make sure contact with the pipe, so that the pipe can be supported at a position in the axial direction away from the front end of the ferrule where the primary seal occurs. Therefore, leakage can be prevented during use of the joint.

Since the structure of the pipe joint of the present invention uses wedge-shaped seal engagement with the pipe, the pipe joint of the present invention can be applied to a wide range of pipe materials having various hardnesses.

[0014]

The above objects and advantages of the present invention will become apparent from the following description and the accompanying drawings. The components of the pipe fitting of the present invention will be apparent from the accompanying drawings. The basic component is an annular fitting body 10 (a portion of which is shown in the drawing), which includes an axial bore 12. The bore 12 intersects the outer end 14, which is flat in shape and perpendicular to the axis of the fixture body 10.
An annular recess 16 is formed in the outer end 14 concentrically with the bore 12, and the recess 16 receives an elastic O-ring 18 having a diameter larger than this axial depth. Therefore, when the O-ring 18 is assembled in the recess 16,
A portion of the O-ring 18 projects axially from the plane of the outer end 14 of the fixture body 10. The fixture body 10 is provided with a male screw 20 adjacent to its outer end 14 and the other end (not shown) of the fixture body 10 is concentric with the bore 12 of the fixture body. It is adapted to receive a conduit with a communicating bore.

The tube 22 to be connected to the fixture body 10 has a cylindrical shape and has a square end 24. A deformable ferrule 26 is attached to the end of the tube 22, and an annular sleeve 28 is attached to the end of the tube 22. Ferrule 26 and sleeve 2
Prior to assembling 8 and 8 to the end of tube 22, nut 30 is placed at the end of tube 22.

The ferrule 26 is formed in an annular shape and is usually made of a material having a hardness higher than that of the tube 22. The ferrule 26 also includes a front portion 32 and a rear portion 34. A bore 36 having a diameter slightly larger than that of the tube 22 is provided inside the ferrule 26. Further, the ferrule 26 has an outer annular tapered surface 38.
The tapered surface 38 extends from a maximum diameter adjacent the rear portion 34 to a minimum diameter adjacent the front portion 32. Further, at the rear end portion of the ferrule 26, as described later in detail, a convex abutment surface 40 that engages with the nut 30 is formed. As will be described later, it is preferable that the outer surface (tapered surface) 38 of the ferrule 26 is provided with an orientation means.

Like the ferrule 26, the sleeve 28
Is usually made of a material having a hardness higher than that of the tube 22. A flat sealing surface 42 is provided at the front end of the sleeve 28. The sealing surface 42 is located in a plane perpendicular to the axis of the sleeve 28, aligned with the flat outer end 14 of the fixture body 10 and the O-ring 1.
8 to form a fluid-tight seal therebetween. An inner annular tapered cam surface 44 is provided at the rear end of the sleeve 28, and the cam surface 44 is formed by the ferrule 2.
It rests on the outer surface 38 of 6 and engages with it. The outer surface 45 of the sleeve 28 is conical and converges towards the free end of the sleeve 28. The rear end of the sleeve 28 is not supported, and has a cantilever structure that applies a pressing force to the ferrule 26, as will be described later. Also, the sleeve 28 is provided with a circumferential inward undercut 46 so that the end of the tube 22 can be tightly received. The undercut 46 defines a forward outwardly extending conical surface which extends the end 24 of the tube 22 outwardly to provide a mechanical lock between the sleeve 28 and the tube 22. And establish tube 22
The end 24 of the.

As is apparent from FIGS. 2, 4, 8 and 9, the angle of the conical surface (outer taper surface) 38 with respect to the axis of the ferrule 26 depends on the conical surface of the sleeve 28 (tapered cam). It is smaller than the angle of the surface 44 by several degrees. Nut 3
0 is provided with a female screw 48 for screwing a nut 30 onto the male screw 20 of the fixture body 10. The nut 30 is also provided with a bore 50 of maximum diameter that is dimensioned to receive the tube 22 and enclose the ferrule 26 and sleeve 28. Further, the nut 30 is provided with a shoulder portion 52 extending inward in the radial direction,
The shoulder 52 has an annular conical cam surface 54 that engages the abutment surface 40 of the ferrule 26. The inner diameter 56 of the shoulder 52 is slightly larger than the outer diameter of the tube 22. The cylindrical surface of the sleeve where the inner diameter (bore) 36 of the ferrule 26, the inner diameter 56 of the nut 30, and the surface (tapered cam surface) 44 intersect is the same. A flat surface (not shown) that engages with a wrench is provided on the outer surface of the nut 30, and the nut 30 can be screwed into the male screw 20 of the fixture body 10 by gripping the flat surface with a wrench or the like. .

When assembling, first, the nut 30 is attached to the pipe 22.
Of the ferrule 26 and then slides the ferrule 26 into the end 24 of the tube 22 with its surface (abutment surface) 40 facing the cam surface 54 of the nut 30. The sleeve 2 is then moved until the end 24 of the tube 22 is aligned with the undercut 46.
8 is placed at the front end of the tube 22 and the nut 30 is pre-threaded onto the male thread 20 of the fixture body 10 as shown in FIG.

When the compression nut 30 is rotated by a predetermined number of revolutions to tighten the nut 30 and the nut 30 is moved to the right as viewed in FIGS. 1 to 3, the cam surface 54 of the nut 30 causes the abutment of the ferrule 26 to abut. Engage with surface 40, which pushes ferrule 26 axially forward, engaging abutment surface 38 of ferrule 26 and cam surface 44 of sleeve 28. As the ferrule 26 moves forward, the shape of the engagement surface causes the front portion 32 of the ferrule 26 to begin to deform inward into the tube 22, which pushes the tube 22 and sleeve 28 forward, As shown in FIG. 2, the sealing surface 42 of the sleeve 28 is the sealing surface 14 of the fixture body 10 and the O-ring 1.
Proper assembly of the fitting is achieved by sealingly engaging with 8. As the ferrule 26 moves forward, the front portion 32 of the ferrule 26 begins to deform inwardly into the tube 22 due to the shape of the engagement surface, which pushes the tube and sleeve 28 forward and forces the sleeve sealing surface 42 into the fitting body. A sealing engagement is made with the sealing surface 14 and the O-ring 18 (FIG. 2). As the nut 30 continues to be tightened, the ferrule 26 is pushed further forward and the front portion 32 of the ferrule 26 is deformed inwardly into a wedge-shaped metal-to-metal seal engagement with the tube 22. This creates a primary seal between the pipe 22 and the fitting, with the front end of the pipe 22
The undercut 46 and the annular recess formed by the undercut 46 are pressed into sealing engagement therewith. In addition, the rear portion 34 of the ferrule 26 also has the shape of the abutting surface 40 of the ferrule 26, which will be described later.
It is transformed inward into 2. This allows ferrule 2
Bend 6 (FIG. 3) to help dampen vibrations.
If the nut 30 is rotated by a predetermined number of rotations, the nut 30
The clamping is stopped, at which point the fluid tight assembly is established.

Depending on the hardness and wall thickness of the tube material forming the tube 22, the end 24 of the tube 22 is flared outwardly by an undercut 46, while at the same time the wedge engagement of the tube 22 and ferrule 26. Thereby, the pipe 22 is deformed inward as shown in FIGS. 3 and 5. This flaring and deformation of the tube 22 provides a strong resistance to axial forces acting on the tube 22 in an attempt to separate the tube 22 from the fixture body 10. However, even when the deformation or spreading is minimal, such as when joining tubes made of relatively hard materials such as stainless steel, the ferrule 26 still has high friction with the tube 22 due to the wedge-shaped engagement. Force is applied to keep the tube 22 connected to the fixture body 10. Also, even when the tube has a non-uniform surface, an effective seal is established that forms a fluid tight assembly.

The tight fit of the end 24 of the tube 22 into the undercut 46 provides several advantages. The first advantage is that a fluid tight seal is usually achieved even though the end 24 of the tube 22 is not an exact square, and the tube 2
A primary seal is formed between the 2 and the ferrule 26. A second advantage is that the sleeve 28 is mechanically locked to the end 24 of the tube 22 to ensure that the sleeve 28 is retained in the tube 22 when the coupling is uncoupled. The third advantage is that the innermost part of the undercut surface is formed so as to return toward the tube 22,
And an undercut 46 to prevent the end 24 of the tube 22 from being radially crushed during tightening the nut 30 and compressing the ferrule 26 as shown in FIG.
Is to be retained.

As shown in FIGS. 4 and 5, the ferrule 2
If the O-ring 58 is installed in the sleeve 28 before the 6 enters the sleeve 28, the O-ring 58 is deformed and pushed in when the coupling of the joint is completed, and the O-ring 58 is adjacent to the end portion (front portion) 32 of the ferrule 26. At this point, the tube 22, ferrule 26 and sleeve 28 are hermetically sealed together (FIG. 5).

The preferred construction of ferrule 26 is shown in greater detail in FIGS. 6 and 7. Since the groove 64 that surrounds the ferrule 26 is provided at a position adjacent to the end (rear portion) 34 on the larger diameter side of the ferrule 26, the person who assembles the joint first determines which end of the ferrule 26 on which side. It makes it possible to quickly decide whether to insert at the end 24 of the tube 22. The display groove 64 has a small size joint, that is, the ferrule is relatively small, and unless the alignment groove 64 is provided, it is difficult to distinguish the end portion on the large diameter side and the end portion on the small diameter side. It is especially effective in some cases.

The outer end portion (abutting surface) 40 of the ferrule 26
Is the outer gradual radius 60
And a smaller inner radius 62. Since the cam surface 54 of the nut 30 is conical, the surface 6
There is a "line" contact between 0 and 54. For this reason,
It is possible to reduce friction between these engagement surfaces, and therefore torque required to rotate the nut 30, and prevent rotation of the ferrule 26 when the nut 30 rotates. The inner radius 62 can eliminate stress points in the tube 22 when the end 34 of the ferrule 26 is pushed into the tube 22.

While tightening the compression nut 30, the pipe 22
, Sleeve 28, ferrule 26 and compression nut 30
For the best understanding of the interrelationship of the cam surface 54 with the cam surface 54, please refer to FIGS. 8-12, which depicts these components in schematic lines for purposes of illustration. In FIG. 8, the relationship between the components is that the compression nut 3 is placed before the “hand tightening” state.
This is the relationship that occurs when 0 is rotated 1/2. In this state, the cam surface 54 of the nut 30 has the ferrule 26
Of the ferrule 26, the nose of the ferrule 26 first engages the cam surface 44 of the sleeve 28. Ferrule 2
The surface 66 of 6 is slightly convex and is substantially parallel to the cam surface 54 of the nut 30 so that the force applied to the ferrule 26 is axially oriented as indicated by arrow A. Therefore, sufficient force to deform ferrule 26 has not yet been exerted by nut 30.

FIG. 9 shows the "manual tightening" relationship in which the nut 30 is tightened by hand.
When the zero cam surface 54 engages the surface 66 of the ferrule 26, the ferrule 26 moves substantially axially to the right. The nose of the ferrule 26 engages the cam surface 44 of the sleeve 28, which causes the cam surface 44 of the sleeve 28 to exert a substantially radial force inward as indicated by arrow B. To work. As is apparent from FIG. 9, force B deforms the nose of ferrule 26 to engage the surface of tube 22.

FIG. 10 shows "tightening by hand" in FIG.
From the relationship, the relationship of each component when the nut 30 is rotated about 1/2 in the tightening direction is shown. In these conditions, the force B is deforming the nose of the ferrule 26 inward into the material of the tube 22 and the ferrule 2
6 is moved to the right to the extent that cam surface 44 of sleeve 28 and surface 38 of ferrule 26 are substantially parallel and adjacent during engagement. The nose region of ferrule 26 is pushed inward until it penetrates deeper into tube 22, thereby forming a primary metal-to-metal seal relationship between ferrule 26 and tube 22.

FIG. 11 shows the state of the components obtained by rotating the compression nut 30 one more complete rotation from the "hand tightening" state of FIG. The nose region (front) 32 of the ferrule 26 is more deeply embedded within the tube 22 by the inward force exerted on the ferrule 26 by the cam surface 44 of the sleeve 28. In addition, the ferrule 26
Due to the large axial force applied to it, it is beginning to assume a "bent" shape. Further, as can be seen from FIG. 11, the cam surface 54 of the nut 30 is beginning to engage with the convex radius 60 of the ferrule 26, and the vector of force between the cam surface 54 and the convex radius 60 is the ferrule 26. Radius 6
2 has a radial component that engages the surface of tube 22.

FIG. 12 shows a state in which the nut 30 is fully tightened by rotating the nut 30 about one and a half rotations further from the "hand tightening" state of FIG. In these conditions, the axial force acting on the ferrule 26 is large and the nose of the ferrule 26 is deeply embedded in the tube 22 to achieve an effective seal. Further, the ferrule 26 is largely bent, and the cam surface 54 of the nut 30 is
Engages the radius 60 of the ferrule 26 so that the force vector indicated by arrow C has a large radial component. Ferrule 26 that engages cam surface 54 of nut 30
When the outer end 40 of the ferrule 26 is thus radially compressed, the outer end 40 of the ferrule 26 is slightly embedded within the tube 22, thereby causing the ferrule 26 to be flush with the ferrule 26 at the surface 62 of the ferrule 26. A positive mechanical interconnection with the tube 22 is formed. This positive mechanical interconnection between the ferrule 26 and the tube 22 on the surface 62 allows the tube 22 to
Is strongly supported against the fitting at a position axially spaced from the primary metal-to-metal seal at the nose region 32 of the ferrule 26. Therefore, tube 2
The bending and the vibration occurring in the No. 2 are caused by the radius 62 of the ferrule 26.
Is not absorbed and is not transmitted to the nose end of the ferrule 26 where the seal is formed. Therefore, a joint using the concept of the present invention can withstand large vibrations without causing leakage.

Further, as is apparent from FIG. 12, since the bent shape of the ferrule 26 has an inherent elasticity, the joint can absorb the vibration without impairing the sealing efficiency. This feature of the invention is characterized by the sleeve 2
The force exerted by 8 on the ferrule 26 is augmented by the cantilevered support structure of the sleeve 28 which is configured to allow the outer end 68 of the sleeve 28 to elastically deform outward. This outward deformation of the sleeve 28 is indicated by the arrow D in FIGS. This inherent elasticity of the cantilever end of the sleeve 28 maintains a strong pressing force that presses the ferrule 26 inward in the radial direction, so that even if vibrations act on the joint, it tends to cause leakage to the joint. You can resist more than anything.

The outer taper surface 45 of the sleeve 28 prevents the cantilevered outer end 68 of the sleeve 28 from engaging the bore 50 of the nut 30 when the ferrule 26 is compressed. Can bend outwards. Further, since the wall thickness of the outer end portion of the sleeve 28 is thin due to the tapered surfaces 44 and 45, the sleeve 28 is bent outward during the compression of the ferrule 26 and maintains the pressing force against the ferrule 26 described above. You can

Those skilled in the art will appreciate that various changes can be made without departing from the spirit and scope of the invention.

[Brief description of drawings]

FIG. 1 is a diametrical cross-sectional side view showing a flat seal type pipe joint according to the present invention, showing a state after initial assembly before tightening a compression nut of the pipe joint.

FIG. 2 is a side view similar to FIG. 1, showing the relationship of the components after rotating the nut towards the fully assembled position.

FIG. 3 is a side view similar to FIGS. 1 and 2, showing the fitting in the fully assembled position.

FIG. 4 is an enlarged detail view of the sleeve end, ferrule and cam surface of the nut, with the relationship of FIG. 2 prior to compression and axial displacement of the ferrule and an optional seal ring between the sleeve and tube. It shows a state of being provided.

FIG. 5 is an enlarged detail view of the end of the sleeve, the ferrule and the cam surface of the nut, with the ferrule fully compressed,
Figure 4 illustrates the relationship of Figure 3 with the optional seal ring in a compressed state.

FIG. 6 is an enlarged side view of a ferrule having alignment grooves formed therein.

7 is a half cross-sectional view of the ferrule of FIG. 6 taken along line 7-7 of FIG.

FIG. 8 is an enlarged view schematically showing the end portion of the sleeve, the ferrule and the cam surface of the nut, showing the components when the nut is turned 1/2 turn before the “tightening by hand” rotation of the compression nut. Is shown.

FIG. 9 is an enlarged view similar to FIG. 8, showing the components in the “hand tighten” position of the compression nut.

10 is an enlarged view similar to FIG. 9, showing the components when the nut is rotated 1/2 turn beyond the position shown in FIG. 9.

11 is an enlarged view similar to FIG. 10, showing the components when the nut has been fully rotated once beyond the “hand tightening” relationship of FIG. 9.

FIG. 12 is an enlarged view similar to FIG. 11, showing the shapes of the components when the nut is rotated one and a half turns beyond the “hand tightening” relationship of FIG. 9.

[Explanation of symbols]

 10 Fixture Main Body 16 Annular Recess 18 O-Ring 20 Male Thread 22 Tube 24 Tube End 26 Ferrule 28 Sleeve 30 Nut 32 Front of Ferrule 34 Rear of Ferrule 40 Abutment of Ferrule 42 Sleeve Sealing Surface 44 Tapered of Sleeve Cam surface 45 Outer surface of sleeve 46 Undercut 48 Female thread 58 O-ring 60 Gradient outward radius of ferrule 62 Inner smaller radius of ferrule 64 Alignment groove 66 Face of ferrule 68 Outer end of ferrule

Front Page Continuation (72) Inventor Dennis J Steuersenberger Indiana, USA 46773 Monroville Tillman Road 18102 (56) References JP 60-146990 (JP, A) JP 60-8226 (JP, JP, Y2) Patent 114739

Claims (18)

(57) [Claims] 1. A joint for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, a male thread portion and a sealing surface, wherein the end portion of the flareless tube is provided. A sleeve with one axis adapted to be located in the region, the sleeve facing the rearward end in axially opposed relation to the sealing surface of the fitting. A forward-facing end forming a sealing surface disposed in the manner of: and a forward-facing end for receiving an end of the flareless tube and establishing a metal-to-metal sealing relationship therewith. An annular rearwardly-facing recess formed in the sleeve adjacent to, and a conical surface formed in the recess and forming an undercut for receiving, supporting and flaring the flareless tube. And after the sleeve An inward conical cam surface formed on the sleeve adjacent the inwardly facing end, and further including a front portion, a rear portion having an outer abutment surface, and the flareless tube. An inner diameter approximately equal to the diameter of the outer tapered surface of the sleeve to engage the conical cam surface of the sleeve to deform the front inwardly for a metal-to-metal seal engagement with the cylindrical surface of the flareless tube. And a nut having a thread surrounding the sleeve and the ferrule and having a thread that engages the male threaded portion of the fixture, the nut engaging the abutment surface of the ferrule. A mating inward shoulder, which presses the ferrule forward to engage the tapered surface of the ferrule with the cam surface of the sleeve and to seal the sealing surface of the sleeve. Press against the sealing surface of the fixture And a conical cam surface formed on the shoulder of the nut is adapted to engage the abutment surface of the ferrule, the conical cam surface of the nut When engaging the abutting surface of a ferrule, the rear portion of the ferrule is deformed inward to engage the flareless tube, and the rear portion of the ferrule has a convex surface, and the convex surface Engages with the conical cam surface of the shoulder of the nut and substantially makes line contact with the conical cam surface to reduce frictional forces, and the convex surface of the ferrule allows the convex surface of the ferrule to move during compression of the ferrule. A coupling having a varying relationship to a conical cam surface, the coupling comprising increasing a radial force acting on a rear portion of the ferrule in a final stage of tightening the nut. 2. A joint for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, a male thread portion and a sealing surface, wherein the end portion of the flareless tube is provided. A sleeve with one axis adapted to be located in the region, the sleeve facing the rearward end in axially opposed relation to the sealing surface of the fitting. A forward-facing end forming a sealing surface disposed in the manner of: and a forward-facing end for receiving an end of the flareless tube and establishing a metal-to-metal sealing relationship therewith. An annular rearwardly-facing recess formed in the sleeve adjacent to, and a conical surface formed in the recess and forming an undercut for receiving, supporting and flaring the flareless tube. And facing backwards An inner conical cam surface formed on the sleeve adjacent the end, further comprising a front portion, a rear portion having an outer abutment surface, and a diameter of the flareless tube. An approximately equal inner diameter and an outer tapered surface that engages a conical cam surface of the sleeve to deform inwardly of the front portion for a metal-to-metal seal engagement with a cylindrical surface of the flareless tube. A ferrule and a nut surrounding the sleeve and the ferrule and having a thread for engaging an externally threaded portion of the fitting, the nut having an inner surface for engaging an abutment surface of the ferrule. One shoulder, which presses the ferrule forward to engage the tapered surface of the ferrule with the cam surface of the sleeve and the sealing surface of the sleeve to the fitting. Pressing against the sealing surface of both Establishing a sealing relationship therebetween, wherein the seal face of the fixture is substantially flat and substantially perpendicular to the fixture axis, and the seal face of the sleeve is relative to the sleeve axis. A substantially flat surface lying in a substantially vertical plane, wherein an annular recess is formed in the seal surface of the fixture,
A coupling comprising: an elastic seal disposed within the recess such that a surface of the elastic seal is engageable with a flat surface of the sleeve. 3. A joint for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, a male thread portion and a sealing surface, wherein the end portion of the flareless tube is provided. A sleeve with one axis adapted to be located in the region, the sleeve facing the rearward end in axially opposed relation to the sealing surface of the fitting. A forward-facing end forming a sealing surface disposed in the manner of: and a forward-facing end for receiving an end of the flareless tube and establishing a metal-to-metal sealing relationship therewith. An annular rearwardly-facing recess formed in the sleeve adjacent to, and a conical surface formed in the recess and forming an undercut for receiving, supporting and flaring the flareless tube. And facing backwards An inner conical cam surface formed in the sleep adjacent the end of the flareless tube and a front portion, a rear portion having an outer abutment surface, and a diameter of the flareless tube. An approximately equal inner diameter and an outer tapered surface that engages a conical cam surface of the sleeve to deform inwardly of the front portion for a metal-to-metal seal engagement with a cylindrical surface of the flareless tube. A ferrule and a nut surrounding the sleeve and the ferrule and having a thread for engaging the male threaded portion of the fixture, the nut engaging an abutment surface of the ferrule. One shoulder, which presses the ferrule forward to engage the tapered surface of the ferrule with the cam surface of the sleeve and the sealing surface of the sleeve to the fitting. Pressing against the sealing surface of A sealing relationship is established between the sleeve and the end area of the flareless tube, and an elastic seal ring is attached to an end area of the flareless tube, and the elastic seal ring is attached to a front part of the ferrule. A joint consisting of, engaging with. 4. A joint for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, a male threaded portion and a sealing surface, the end portion of the flareless tube being provided. A sleeve with an axis adapted to be arranged in the region, the sleeve having a rearward facing free end and axially opposed to a sealing surface of the fitting. A forward facing end forming a sealing surface disposed in relation, the sleeve having an inner conical surface converging in the direction of the forward facing end of the sleeve. The sleeve has an outer surface that intersects the rearward-facing end of the sleeve, the radial wall thickness of the sleeve adjacent the rearward-facing end is directed forwards. Less than the wall thickness of the sleeve adjacent the end Further comprising a ferrule, the ferrule comprising a front portion, a rear portion having an outer abutment surface, and an inner diameter substantially equal to the diameter of the flareless tube,
An outer conical surface that engages with the inner conical surface of the sleeve to deform the front portion of the ferrule inward to engage the cylindrical surface of the flareless tube with a metal-to-metal seal engagement. A nut having a thread surrounding the sleeve and the ferrule and engaging a male threaded portion of the fixture, the nut engaging the abutment surface of the ferrule. An inner shoulder that pushes the ferrule forward and engages the outer conical surface of the ferrule with the conical surface of the sleeve to radially move the ferrule. When the nut is completely tightened, the inner conical surface of the sleeve and the outer conical surface of the flareless tube adjacent to the rearward end of the sleeve engage. And turned to the rear of the sleeve Small wall thickness portions of the sleeve adjacent to the parts makes it possible to apply a pressing force end facing the rear of the sleeve is inwardly directed with respect to the ferrule flex radially outward,
When the tightening of the nut is complete, the sealing surface of the fitting engages with the forward facing sealing surface of the sleeve to establish a seal between the fitting and the sleeve, and the outer surface of the sleeve is And a conical surface converging in the direction of the rearward facing end of the sleeve. 5. The seal surface of the fixture is substantially flat and substantially perpendicular to the fixture axis, with the forward facing end of the sleeve relative to the sleeve axis. A flat sealing surface in a substantially vertical plane, an annular recess formed in the sealing surface and intersecting the sealing surface, and disposed in the annular recess. The fitting of claim 4, comprising a resilient seal capable of establishing a sealing relationship with the flat surface of the sleeve. 6. A joint for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, a male threaded portion and a sealing surface, the end portion of the flareless tube being provided. A sleeve with an axis adapted to be arranged in the region, the sleeve having a rearward facing free end and axially opposed to a sealing surface of the fitting. A forwardly facing end forming a sealing surface arranged in relation, the sleeve converging in the direction of the forwardly facing end of the sleeve and said rearwardly facing end. An inner conical surface intersecting the portion, and further comprising a ferrule, the ferrule comprising a front portion, a rear portion having an outer abutment surface, and substantially the flareless. An inner diameter equal to the diameter of the tube,
An outer conical surface that engages with the inner conical surface of the sleeve to deform the front portion of the ferrule inward to engage the cylindrical surface of the flareless tube with a metal-to-metal seal engagement. An outer abutment surface of the ferrule includes a convex surface, and further includes a nut surrounding the sleeve and the ferrule and having a thread for engaging the male thread portion of the fitting. The nut has an inward shoulder having a conical surface converging in a direction toward the flareless tube and away from the ferrule, and when the nut is tightened, the conical shape of the nut is obtained. The surface engages with the convex surface of the ferrule by an annular line, presses the ferrule forward to engage the inner conical surface of the sleeve to compress the ferrule radially, and the nut By tightening the The rule and the sleeve are axially pressed to bring the forward facing seal of the sleeve and the sealing surface of the fixture into a sealing relationship, and further adjacent to one portion of the ferrule and outside the ferrule. A coupling means comprising a display means formed on the conical surface on the one side to visually display a predetermined end portion of the ferrule. 7. The display means comprises an annular groove that surrounds an outer conical surface of the ferrule.
Fittings. 8. A joint for attaching a cylindrical flareless tube having an end and an end region to a tubular fitting having an axis, an external male thread and a sealing surface, the axis having an axis. And having a sleeve overlying the end region of the flareless tube, the sleeve being arranged in axially opposed relation with a rearward facing free end and a sealing surface of the fitting. A forward facing end forming a sealing surface, and an inner conical surface converging in the direction of the forward facing end of the sleeve,
The sleeve converging in the direction of the rearward-facing end of the sleeve and having an outer conical surface intersecting the rearward-facing end of the sleeve and adjoining the rearward-facing end. Has a radial wall thickness less than the wall thickness of the sleeve adjacent the forward facing end of the sleeve and further includes a ferrule having a front portion and a rear portion with an outer abutment surface. And the ferrule engages an inner diameter substantially equal to the diameter of the flareless tube and an inner conical surface of the sleeve to deform the front portion of the ferrule inwardly so that the flareless tube and the metal. An outer conical surface for sealing engagement with a metal, further comprising a nut surrounding the sleeve and the ferrule and having a thread for engaging a threaded portion of the fixture, The nut engages the abutment surface of the ferrule By pressing the ferrule forward by engaging the outer conical surface of the ferrule and the conical surface of the sleeve, and having an inner shoulder portion that contracts the ferrule radially. The converging angle of the inner conical surface of the ferrule is greater than the converging angle of the outer conical surface of the ferrule, so that during tightening of the nut, axial compression of the ferrule causes front portion of the ferrule. The ferrule is curved outward in the radial direction between the rear portion and the rear portion, and when the tightening of the nut is completed, the inner conical surface of the sleeve and the outer conical surface of the ferrule of the sleeve are The rearward-facing end of the sleeve is engaged radially adjacent the rearward-facing end of the sleeve by the reduced wall thickness of the sleeve adjacent the rearward-facing end of the sleeve. To apply an inward biasing force to the ferrule, and upon completion of tightening of the nut, engage the sealing surface of the fixture with the forward facing end of the sleeve, A distinct joint that establishes a seal between the fitting and the sleeve. 9. The seal surface of the fixture is substantially flat and substantially perpendicular to the fixture axis, with the forward facing end of the sleeve relative to the sleeve axis. A flat surface lying in a substantially vertical non-planar plane, an annular recess formed in and intersecting the seal surface of the fixture, and a flat surface of the sleeve disposed in the recess. 9. The fitting of claim 8 having a resilient seal that establishes a sealing relationship with the face. 10. A fitting for attaching a cylindrical flareless tube having an end portion and an end region to a tubular fitting having one axis, an external male thread portion and a sealing surface. A sleeve having one axis and overlying an end region of the flareless tube, the sleeve having a rearward facing end and an axially opposed relationship with a sealing surface of the fixture. A forward facing end forming a sealing surface disposed at, and an inner conical surface intersecting the rearward facing end and converging in the direction of the forward facing end of the sleeve. A ferrule having a front portion and a rear portion with an outer abutment surface, the ferrule having an inner diameter substantially equal to the diameter of the flareless tube and an inner cone of the sleeve. The front part of the ferrule by deforming inward A flareless tube and an outer conical surface that is in metal-to-metal sealing engagement, and an outer abutment surface of the ferrule has a convex surface having a first radius and the first conical surface. A convex surface having a second radius that is smaller than the radius and forms the outer dimension of the abutment surface, and further includes a screw surrounding the sleeve and the ferrule and engaging a threaded portion of the fixture. A nut having an inner shoulder with a conical surface converging towards the flareless tube and away from the ferrule, whereby the nut is tightened during tightening of the nut. The conical surface of the sleeve engages the first convex surface of the ferrule with an annular line that presses the ferrule forward to engage the inner conical surface of the sleeve to compress the ferrule radially. The ferrule Made of a deformable metal and curved axially outwardly between the front and rear portions of the ferrule under axial compression to reduce vibration loading in the joint, A second convex abutment surface of the ferrule defines an outer diameter dimension of the abutment surface that engages a conical surface of the nut when the ferrule is curved so that the A radially inward force vector that presses the rear portion of the ferrule is generated, and by tightening the nut, the ferrule and the sleeve are pressed in the radial direction,
A joint comprising a forward facing sealing surface of the sleeve in sealing relationship with the fitting. 11. A display means is provided on an outer conical surface of the ferrule adjacent to one portion of the ferrule for visually displaying a predetermined end of the ferrule. The fitting described in. 12. The fitting according to claim 11, wherein the indicating means comprises an annular groove extending around the outer conical surface of the ferrule. 13. The converging angle of the inner conical surface of the sleeve is greater than the converging angle of the outer conical surface of the ferrule, which results in axial compression of the ferrule during tightening of the nut. 11. The coupling of claim 10, wherein the ferrule bends radially between its front and rear portions. 14. A ferrule for a compression fitting mounted on a tube adjacent to the end of the tube, the ferrule having a cylindrical bore, an outer surface, a first end, and a second end. A ferrule having an annular main body with different wall thicknesses at both ends in the radial direction, the ferrule being adjacent to one end of the both ends of the ferrule. Formed on the outer surface of the ferrule, and having display means for visually displaying a specific end of the ferrule.
A ferrule characterized by that. 15. The ferrule according to claim 14, wherein the display means comprises an annular groove that surrounds the outer surface of the ferrule. 16. An end region of a flareless tube having one axis and axially spaced cylindrical inner and outer portions in a fixture having an annular sleeve surrounding the inner portion of the flareless tube. Wherein the sleeve is radially spaced from an inner portion of the flareless tube and is radially inwardly converging at a first angle in a direction away from an outer portion of the flareless tube. A conical surface, the fitting having a compression nut, enclosing an outer portion of the flareless tube and converging away from an inner portion of the flareless tube, the compression nut rotating the compression nut. Has an annular conical abutment surface that is axially displaced toward the sleeve and further surrounds an outer portion of the flareless tube and faces the sleeve. And an annular ferrule having an outer conical surface that converges at a second angle, the ferrule being received in and engaged with the conical surface of the sleeve, and the ferrule of the nut. A rear portion engaged by an abutment surface, the rear portion of the ferrule being engaged in line contact with a first radially inwardly convex convex surface by the abutment surface of the nut. A second curved convex surface having a radius smaller than the radius of the first convex surface and directed outward in the radial direction, and the first convergence angle of the sleeve is greater than the second convergence angle of the ferrule. And (a) axially displacing the compression nut abutment surface toward the sleeve to engage the nut abutment surface with the first arcuate surface of the ferrule, and Displace the front part of the ferrule in the axial direction Engaging with the conical surface of the sleeve, and (b) continuously displacing the compression nut abutment surface toward the sleeve in the axial direction, whereby the conical surface of the sleeve and the conical shape of the ferrule. Creating a sufficient axial length engagement with a surface to fit the front portion of the ferrule into the inner portion of the flareless tube,
In addition, the step of bending the ferrule outward in the middle of the front portion and the rear portion thereof due to the difference between the first and second convergence angles, and (c) the compression nut abutting surface toward the sleeve. Displaced axially to continue outward bending of the ferrule until the nut abutment surface engages the second outer convex surface of the ferrule, increasing radial inward to the rear portion of the ferrule. Generating a force thereby causing the rear portion of the ferrule to closely engage and support the outer portion of the flareless tube to attach the end region of the flareless tube. 17. The end region of the flareless tube of claim 16 including the step of: (a) biasing the sleeve radially inwardly against the ferrule to create resistance to abrupt displacements due to vibration. Method. 18. A method of pushing an annular ferrule into a flareless tube having one axis and axially spaced inner and outer portions, the ferrule comprising one axis and the flareless tube. A receiving hole, a front portion, a rear portion, and an outer surface that converges axially from the rear portion toward the front portion, the method comprising: (a) during an initial stage of compression of the ferrule; Displacing the front part of the ferrule axially towards the front part while compressing the front part of the ferrule inwardly so as to fit the front part of the ferrule into the inner part of the flareless tube. (B) engaging the outer surface of the ferrule intermediate the front portion and the rear portion and bending the ferrule outward to further fit the front portion of the ferrule into the inner portion of the flareless tube. And changing the relationship of the rear portion of the flareless tube to the outer portion of the flareless tube, (c) the direction of the compressive force of the rear portion of the ferrule during the final stage of compression of the ferrule. Displacing the ferrules in a radially increasing manner to displace the rear portion of the ferrule predominantly radially inwardly to securely engage the rear portion of the ferrule with the outer portion of the flareless tube. A method having.