High-pressure sealing and gripping device

Claim 2

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; said ferrule means being deformed into gripping engagement with said conduit as by moving said nose portion in a forward direction into a camming mouth so as to be cammed inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the relationship of parts being such that upon torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said coupling body sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 3

The invention of claim 1 in which said coupling body is defined as a composite structure comprised of a male connector element and a connector member with said bore and said sealing surface defined by said connector member and said counterbore and said camming mouth defined by said male connector element with said coupling nut threadedly engaged with said male connector element.

Claim 4

The invention of claim 1 in which said coupling body is defined as a composite structure comprised of a coupling body element and a camming element with said bore and said sealing surface defined by said coupling boDy element and said counterbore and said camming mouth defined by said camming element with said coupling nut threadedly engaged with said coupling body element.

Claim 5

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said coupling body sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 6

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said coupling body sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 7

The invention of claim 4 in which said frustoconical sealing surface of said conduit prior to makeup of the fitting defines a half angle with respect to the axis of said coupling body counterbore less than the half angle defined by said frustoconical sealing surface of said coupling body with respect to the axis of said coupling body counterbore.

Claim 8

The invention of claim 5 in which the difference in recited sealing surface half angles is in the range of about 1* to about 5*.

Claim 9

The invention of claim 5 in which the difference in recited sealing surface half angles is about 2*.

Claim 10

The invention of claim 4 in which said ferrule means is further defined as: a front ferrule received upon said conduit and defined by a body portion having substantially the form of a right circular cylinder and a nose portion having substantially the form of a right circular forwardly converging conical frustum, the exterior surfaces of said body portion and said nose portion being interconnected by a generally concave annular surface, said body portion including a radial base having a frustoconical surface, said right circular forwardly converging conical frustum defining a tapered external forward surface portion, back ferRule received upon said conduit adjacent said front ferrule and rearwardly thereof, said back ferrule being defined by a right circular substantially cylindrical body portion and a nose portion, the forward end of the nose portion of said back ferrule having an external forwardly converging generally frustoconical surface received within the frustoconical surface of said front ferrule, the rearward end of said back ferrule being provided with a generally frustoconical rearwardly converging backface carried on the back ferrule body portion.

Claim 11

The invention of claim 4 in which said ferrule means is defined by a front ferrule and a back ferrule received upon said conduit, said nose portion being defined on said front ferrule and said backface being defined on said back ferrule.

Claim 12

The invention of claim 4 in which a bleed passage to atmosphere is defined in said coupling body providing communication to the interior of said coupling body at a location between said coupling body sealing surface and said ferrule means.

Claim 13

The invention of claim 4 in which said coupling nut threadedly engages external threads of said coupling body.

Claim 14

The invention of claim 4 in which said coupling nut threadedly engages internal threads of said coupling body.

Claim 15

The invention of claim 4 in which said coupling body is defined by a composite structure including a coupling body element and a generally annular camming element, said bore and said coupling body sealing surface being defined by said coupling body element, and said counterbore and said camming mouth being defined by said annular camming element, the composite structure being arranged such that said conduit is inserted through said camming element and into said coupling body element.

Claim 16

The invention of claim 13 in which said annular camming element is threadedly received within said coupling body element.

Claim 17

The invention of claim 13 in which a bleed passage to atmosphere is defined in said coupling body element providing communication to the interior of said coupling body element at a location between the sealing surface of said coupling body element and said ferrule means.

Claim 18

The invention of claim 13 in which a bleed passage to atmosphere is defined in said camming element and said coupling nut providing communication to the interior of said coupling body element at a location between the sealing surface of said coupling body element and said ferrule means.

Claim 19

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body defined by a composite structure including a male connector element and a connector member; said male connector element having a first end, a second end, a bore, a counterbore at said first end for receiving said conduit, and a sealing surface at said first end, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial rearwardly opening generally frustoconical camming mouth adapted to surround said conduit when inserted in the male connector element at said first end, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said counterbore, said second end of said male connector element being provided with external threads adapted to be received within said connector member; said connector member having a bore, a counterbore having internal threads and a generally frustoconical sealing surface; said second end of said male connector element further including a nose portion adapted to sealingly abut said frustoconical sealing surface of said connector member as said second end is advanced into said connector member; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwArdly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said male connector element and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said male connector element, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed radially inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said male connector element sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said male connector element sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 20

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body defined by a composite structure including a male connector element and a connector member; said male connector element having a first end, a second end, a bore, a counterbore at said first end for receiving said conduit, and a sealing surface at said first end, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial rearwardly opening generally frustoconical camming mouth adapted to surround said conduit when inserted in the male connector element at said first end, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said counterbore, said second end of said male connector element being provided with external threads adapted to be received within said connector member; said connector member having a bore, a counterbore having internal threads and a generally frustoconical sealing surface; said second end of said male connector element further including a nose portion adapted to sealingly abut said frustoconical sealing surface of said connector member as said second end is advanced into said connector member; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwArdly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said male connector element and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said male connector element, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed radially inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said male connector element sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said male connector element sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 21

The invention of claim 17 in which said nose portion of said male connector element is integral with said male connector element.

Claim 22

The invention of claim 17 in which said nose portion of said male connector element is further defined as a generally frustoconical surface at said second end of said male connector element, the frustoconical surface of said connector member defining a half angle with respect to the axis of said connector member counterbore greater than the half angle defined by the frustoconical surface of said nose portion of said male connector element.

Claim 23

The invention of claim 17 in which a bleed passage to atmosphere is defined in said male connector element at said first end providing communication to the interior of said male connector element at a location between said male connector element sealing surface and said ferrule means.

Claim 24

The invention of claim 17 in which a bleed passage to atmosphere is defined in said male connector element at said second end providing communication to the interior of said connector member at said male connector element nose portion.

Claim 25

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body defined by a composite structure including a male connector element and a connector member; said connector member having a bore, a counterbore, and a sealing surface, said counterbore of said connector member adapted to receive said male connector element; said male connector element including a bore and a rearwardly opening, generally frustoconical camming mouth adapted to surround said conduit when inserted through said male connector element and into engagement with said connector member, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said bore of said male connector element; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than thE half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said male connector element and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said connector member sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said connector member sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 26

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body defined by a composite structure including a male connector element and a connector member; said connector member having a bore, a counterbore, and a sealing surface, said counterbore of said connector member adapted to receive said male connector element; said male connector element including a bore and a rearwardly opening, generally frustoconical camming mouth adapted to surround said conduit when inserted through said male connector element and into engagement with said connector member, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said bore of said male connector element; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than thE half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said male connector element and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the relationship of the parts being such that upon initial torquing of said coupling nut, said nose portion of said ferrule means is moved in a forward direction into said camming mouth thereby to be cammed inwardly into engagement with the exterior surface of said conduit producing deformation of said conduit; upon further torquing of said coupling nut said conduit is driven forward thus advancing said conduit sealing surface into sealing abutment with said connector member sealing surface establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said connector member sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 27

The invention of claim 22 in which a bleed passage to atmosphere is defined in said male connector element providing communication to the interior of said connector member at said conduit sealing surface.

Claim 28

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrule means, said ferrule means becomes slightly deformed thereby to come into contact with said conduit and apply local force around the circumference of said conduit, said local force having a first force component normal to the axis of said ferrule means bore and acting to reduce the diameter of said conduit at said ferrule means, and a second force component parallel to the axis of said ferrule means bore and acting to place an axial compressive stress in said conduit; upon further application of a substantially axial compressive force said ferrule means becomes more deformed and advances toward said conduit sealing surface thus to preload said one end of said conduit establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 29

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrule means, said ferrule means becomes slightly deformed thereby to come into contact with said conduit and apply local force around the circumference of said conduit, said local force having a first force component normal to the axis of said ferrule means bore and acting to reduce the diameter of said conduit at said ferrule means, and a second force component parallel to the axis of said ferrule means bore and acting to place an axial compressive stress in said conduit; upon further application of a substantially axial compressive force said ferrule means becomes more deformed and advances toward said conduit sealing surface thus to preload said one end of said conduit establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the yield stress of said conduit in compression being such that said conduit maintains a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 30

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrule means, said ferrule means becomes slightly deformed thereby to come into contact with said conduit and induce an elastic compression wave in said conduit, the wave-inducing force imparted to said conduit by said ferrule means having a first force component normal to the axis of said ferrule means bore and acting to maintain said ferrule means in contact with said conduit and a second force component parallel to the axis of said ferrule means bore and acting to advance said wave toward said one end of said conduit thus to advance said conduit sealing surface into sealing abutment with said coupling body sealing surface; upon further application of a substantially axial compressive force said ferrule means becomes more deformed to preload elastically said one end of said conduit establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the yield stress of said conduit in compression being such that said conduit remains sufficiently elastic upon deformation of said ferrule means thus to maintain a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 31

A fitting comprising: a conduit having a substantially cylindrical exterior surface and a generally frustoconical forwardly converging sealing surface at one end thereof said sealing surface having been formed on said conduit prior to initial makeup of said fitting; a coupling body having a bore, a counterbore for receiving said conduit, and a generally frustoconical rearwardly opening sealing surface, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generally frustoconical rearwardly opening camming mouth adapted to surround said conduit when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; ferrule means received upon said conduit, said ferrule means having a bore and including a generally frustoconical forwardly converging nose portion defining a half angle with respect to the axis of said ferrule means bore less than the half angle defined by said camming mouth, the rearward end of said ferrule means being provided with a backface; a coupling nut threadedly engaged with said coupling body and provided with a thrust surface disposed in axially spaced opposition to said camming mouth and engaging said backface of said ferrule means, said coupling nut and camming mouth together defining an annular chamber surrounding said conduit when inserted in said coupling body, within which said ferrule means is adapted to be received; the portion of said conduit gripped by said ferrule means having a substantially uniform outside diameter prior to deformation of said ferrule means; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrule means, said ferrule means becomes slightly deformed thereby to come into contact with said conduit and induce an elastic compression wave in said conduit, the wave-inducing force imparted to said conduit by said ferrule means having a first force component normal to the axis of said ferrule means bore and acting to maintain said ferrule means in contact with said conduit and a second force component parallel to the axis of said ferrule means bore and acting to advance said wave toward said one end of said conduit thus to advance said conduit sealing surface into sealing abutment with said coupling body sealing surface; upon further application of a substantially axial compressive force said ferrule means becomes more deformed to preload elastically said one end of said conduit establishing a high integrity seal on a diameter less than the inside diameter of said ferrule means in a deformed state; the yield stress of said conduit in compression being such that said conduit remains sufficiently elastic upon deformation of said ferrule means thus to maintain a thrust load on said coupling body sealing surface of a magnitude substantially equal to or greater than the hydraulic force within said conduit acting against said conduit sealing surface.

Claim 32

A phased controlled sequential tube fitting comprising: a coupling body having a bore, a counterbore for receiving a tube, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generAlly frustoconical rearwardly opening camming mouth adapted to surround a tube when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; a front ferrule adapted to be received upon a tube and defined by a body portion having substantially the form of a right circular cylinder and a nose portion having substantially the form of a right circular forwardly converging conical frustum, the exterior surfaces of said body portion and said nose portion being interconnected by a generally concave surface, the external surface of said nose portion, prior to makeup of the fitting, defining a half angle with respect to the axis of said counterbore less than that defined by said camming mouth, a front ferrule bore defined within said front ferrule coaxial with the counterbore of said coupling body, the forward end of the nose portion of said front ferrule terminating with a curved apical zone, the front ferrule being provided at the rearward end thereof with a coaxial rearwardly opening generally frustoconical surface joining the radial base of the front ferrule with the wall defining the bore of the front ferrule, said frustoconical surface of said front ferrule having a radial extent at its intersection with the radial base, substantially less than half the greatest difference between the inner and outer radii of the front ferrule body portion; a back ferrule adapted to be received upon a tube adjacent said front ferrule and rearwardly thereof, said back ferrule being defined by a right circular substantially cylindrical body portion and a nose portion, the back ferrule being provided with a back ferrule bore coaxial with said counterbore of said coupling body, the outer diameter of the body portion of said back ferrule being substantially equal to the outer diameter of the body portion of said front ferrule, the greatest radial thickness of the nose portion of said back ferrule being substantially less than one-half the greatest difference between the inner and outer radii of the body portion of said back ferrule, the forward end of the nose portion of said back ferrule having an external forwardly converging generally frustoconical surface received within said frustoconical surface of said front ferrule, the rearward end of said back ferrule being provided with a generally frustoconical rearwardly converging backface defined on the body portion; a coupling nut threadedly engaged with said coupling body and provided with a coaxial internal rearwardly converging generally frustoconical thrust surface disposed in axially spaced opposition to the camming mouth and engaging the backface of said back ferrule, the coupling nut and the camming mouth together defining an annular chamber surrounding a tube when inserted in the coupling body, within which the front and back ferrules are received; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrules a major part of the front ferrule deformation will be accomplished prior to the time deformation of the back ferrule is initiated.

Claim 33

A phased controlled sequential tube fitting comprising: a coupling body having a bore, a counterbore for receiving a tube, said counterbore being substantially cylindrical throughout a portion of its length and being provided with a coaxial generAlly frustoconical rearwardly opening camming mouth adapted to surround a tube when inserted in said coupling body, said camming mouth forming a predetermined forwardly extending half angle with respect to the axis of said coupling body counterbore; a front ferrule adapted to be received upon a tube and defined by a body portion having substantially the form of a right circular cylinder and a nose portion having substantially the form of a right circular forwardly converging conical frustum, the exterior surfaces of said body portion and said nose portion being interconnected by a generally concave surface, the external surface of said nose portion, prior to makeup of the fitting, defining a half angle with respect to the axis of said counterbore less than that defined by said camming mouth, a front ferrule bore defined within said front ferrule coaxial with the counterbore of said coupling body, the forward end of the nose portion of said front ferrule terminating with a curved apical zone, the front ferrule being provided at the rearward end thereof with a coaxial rearwardly opening generally frustoconical surface joining the radial base of the front ferrule with the wall defining the bore of the front ferrule, said frustoconical surface of said front ferrule having a radial extent at its intersection with the radial base, substantially less than half the greatest difference between the inner and outer radii of the front ferrule body portion; a back ferrule adapted to be received upon a tube adjacent said front ferrule and rearwardly thereof, said back ferrule being defined by a right circular substantially cylindrical body portion and a nose portion, the back ferrule being provided with a back ferrule bore coaxial with said counterbore of said coupling body, the outer diameter of the body portion of said back ferrule being substantially equal to the outer diameter of the body portion of said front ferrule, the greatest radial thickness of the nose portion of said back ferrule being substantially less than one-half the greatest difference between the inner and outer radii of the body portion of said back ferrule, the forward end of the nose portion of said back ferrule having an external forwardly converging generally frustoconical surface received within said frustoconical surface of said front ferrule, the rearward end of said back ferrule being provided with a generally frustoconical rearwardly converging backface defined on the body portion; a coupling nut threadedly engaged with said coupling body and provided with a coaxial internal rearwardly converging generally frustoconical thrust surface disposed in axially spaced opposition to the camming mouth and engaging the backface of said back ferrule, the coupling nut and the camming mouth together defining an annular chamber surrounding a tube when inserted in the coupling body, within which the front and back ferrules are received; the relationship of the parts being such that upon application of a substantially axial compressive force to said ferrules a major part of the front ferrule deformation will be accomplished prior to the time deformation of the back ferrule is initiated.