JOINT FOR PLASTIC PIPE
First Claim
1. An improvement in a joint for connecting a plastic pipe to fittings or metal pipes comprising:
- a hollow body member having an end portion, said body member having a bore extending at least through said end portion, a first counterbore terminating at its inner end in an inwardly extending annular shoulder surrounding said bore and terminating at its outer end in an outwardly extending annular shoulder, a second counterbore of a diameter greater than the diameter of said first counterbore and substantially equal to the outside diameter of the plastic pipe, said second counterbore extending outwardly from the annular shoulder of the outer end of said first counterbore and terminating in an outwardly facing and flaring frustoconicAl shoulder;
an elongated rigid tubular sleeve element having one end portion fixedly secured in said first counterbore against axial movement relative said body member and the other end projecting substantially beyond the frustoconical shoulder of said body member, said tubular sleeve element having an exterior diameter substantially equal to the interior diameter of the pipe at least on the portion of the same received in the pipe and said tubular sleeve element having, on the exterior surface of the portion projecting beyond the frustoconical shoulder, an annular recess means of a substantial overall axial extent and uniform depth, said annular recess means terminating in oppositely disposed frustoconical inner and outer end walls at its overall axial extent, the outer juncture of said inner frustoconical end wall lying substantially in a projection of said frustoconical shoulder of said body member, the exterior surface of said sleeve element between the fixedly secured end of the same and the outer juncture of said inner frustoconical end wall defining with said second counterbore an annular chamber of substantial axial extent for snugly receiving an end portion of the plastic pipe;
follower means including a nut threadedly received by said body member, said follower means having an inner diameter at least equal to the exterior diameter of the plastic pipe and a frustoconical inner surface opposed to and spaced from said frustoconical shoulder of said body member to define therebetween a variable volume annular compression chamber having an initial axial length greater than the overall axial extent of said annular recess means on said sleeve element;
a noncompressible annular gasket seal made of a deformable material and having an axial cross section when relaxed generally complementary to said compression chamber prior to volume of the compression chamber being reduced and an axial extent greater than the axial extent of said annular recess means on said sleeve element; and
means for limiting and tightening of said nut on said body member to a position where the frustoconical inner surface of said follower means reduces the volume of said compression chamber and where a projection of said frustoconical inner surface of said follower means extends through the outer junction of said outer frustoconical end wall of the said annular recess means on said sleeve element so that said gasket seal deforms the plastic pipe without extrusion into said annular recess to completely fill the same.
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Accused Products
Abstract
A joint for connecting a nonmetallic flareless plastic pipe or tube to fittings or metal pipes, the joint including two relatively movable members having a variable volume compression chamber therebetween, one of the members fixedly supporting a relatively rigid sleeve element insertable into the plastic pipe to provide a backing therefor. The sleeve element is provided with an annular recess on its exterior discriminately arranged with respect to length, depth and location relative to the compression chamber whereby a noncompressible annular gasket seal made of a deformable elastic material and positioned within the compression chamber will cause the plastic pipe to deform and completely fill the recess in the sleeve element without extrusion or thinning of the walls of the plastic pipe.
114 Citations
21 Claims
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1. An improvement in a joint for connecting a plastic pipe to fittings or metal pipes comprising:
- a hollow body member having an end portion, said body member having a bore extending at least through said end portion, a first counterbore terminating at its inner end in an inwardly extending annular shoulder surrounding said bore and terminating at its outer end in an outwardly extending annular shoulder, a second counterbore of a diameter greater than the diameter of said first counterbore and substantially equal to the outside diameter of the plastic pipe, said second counterbore extending outwardly from the annular shoulder of the outer end of said first counterbore and terminating in an outwardly facing and flaring frustoconicAl shoulder;
an elongated rigid tubular sleeve element having one end portion fixedly secured in said first counterbore against axial movement relative said body member and the other end projecting substantially beyond the frustoconical shoulder of said body member, said tubular sleeve element having an exterior diameter substantially equal to the interior diameter of the pipe at least on the portion of the same received in the pipe and said tubular sleeve element having, on the exterior surface of the portion projecting beyond the frustoconical shoulder, an annular recess means of a substantial overall axial extent and uniform depth, said annular recess means terminating in oppositely disposed frustoconical inner and outer end walls at its overall axial extent, the outer juncture of said inner frustoconical end wall lying substantially in a projection of said frustoconical shoulder of said body member, the exterior surface of said sleeve element between the fixedly secured end of the same and the outer juncture of said inner frustoconical end wall defining with said second counterbore an annular chamber of substantial axial extent for snugly receiving an end portion of the plastic pipe;
follower means including a nut threadedly received by said body member, said follower means having an inner diameter at least equal to the exterior diameter of the plastic pipe and a frustoconical inner surface opposed to and spaced from said frustoconical shoulder of said body member to define therebetween a variable volume annular compression chamber having an initial axial length greater than the overall axial extent of said annular recess means on said sleeve element;
a noncompressible annular gasket seal made of a deformable material and having an axial cross section when relaxed generally complementary to said compression chamber prior to volume of the compression chamber being reduced and an axial extent greater than the axial extent of said annular recess means on said sleeve element; and
means for limiting and tightening of said nut on said body member to a position where the frustoconical inner surface of said follower means reduces the volume of said compression chamber and where a projection of said frustoconical inner surface of said follower means extends through the outer junction of said outer frustoconical end wall of the said annular recess means on said sleeve element so that said gasket seal deforms the plastic pipe without extrusion into said annular recess to completely fill the same.
- a hollow body member having an end portion, said body member having a bore extending at least through said end portion, a first counterbore terminating at its inner end in an inwardly extending annular shoulder surrounding said bore and terminating at its outer end in an outwardly extending annular shoulder, a second counterbore of a diameter greater than the diameter of said first counterbore and substantially equal to the outside diameter of the plastic pipe, said second counterbore extending outwardly from the annular shoulder of the outer end of said first counterbore and terminating in an outwardly facing and flaring frustoconicAl shoulder;
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2. A joint as claimed in claim 1 in which said means for limiting tightening of the nut on said body member includes a shoulder on said body member on which said nut bottoms.
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3. A joint as claimed in claim 1 in which said inner and outer frustoconical end walls of the annular recess means of said sleeve element have an angle in the order of 45* relative to a longitudinal axis of said sleeve element.
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4. A joint as claimed in claim 1 in which said frustoconical shoulder of said body member and said frustoconical surface of said follower means each has an angle to the longitudinal axis of the joint in the order of 30*.
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5. A joint as claimed in claim 1 in which the annular recess means of said sleeve element has a surface with means thereon for gripping the interior of the plastic pipe when said nut is tightened on said body member to thereby resist relative rotation between said plastic pipe and said sleeve element as said plastic pipe is being deformed.
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6. A joint as claimed in claim 5 in which said means to resist relative rotation between said sleeve element and said plastic pipe includes at least one longitudinally extending rib projecting outwardly from the surface of said annular recess.
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7. A joint as claimed in claim 5 in which said means to resist relative rotation between said sleeve element and the plastic pipe includes knurling on the surface of said recess.
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8. A joint as claimed in claim 1 in a dry film low friction lubricant coated on its Interior surface to thereby reduce friction between the follower means and said gasket seal when a joint is made up.
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9. A joint as claimed in claim 1 including a semirigid washer substantially L-shaped in radial section and positioned between said frustoconical surface of said follower nut and said gasket seal, said washer being distorted by said frustoconical surface upon makeup of the joint to prevent cold flow of said gasket seal from beneath the annular flange of said follower nut.
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10. A joint as claimed in claim 9 in which said semirigid washer is made of a low friction plastic material.
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11. A joint as claimed in claim 1 in which the outer end of said sleeve element is slightly rounded inwardly, whereby a free edge of said sleeve element is spaced from the interior of the plastic pipe.
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12. A coupling joint as claimed in claim 1 in which said sleeve element is fixedly secured by a press fit in sad first counterbore.
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13. A joint as claimed in claim 1 in which said sleeve element is fixedly secured by threading the same in said first counterbore.
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14. A joint as claimed in claim 1, in which said annular recess means which said follower means has a at least two axially spaced annular recesses on the exterior of said tubular sleeve element.
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15. A joint as claimed in claim 1, in which the depth of said annular recess means is in the order of one thirty-second of an inch.
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16. A joint as claimed in claim 1, in which said nut of said follower means is a gland nut and in which said frustoconical inner surface of said follower means is on an antifriction ring arranged to be urged axially of the pipe against the gasket seal by said nut.
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17. A joint as claimed in claim 16 in which said body member includes a third counterbore extending outwardly from the outwardly facing and flaring frustoconical shoulder, at least a portion of said third counterbore defining with said last mentioned shoulder and with said antifriction ring the variable compression chamber for said gasket seal.
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18. A joint as claimed in claim 17, in which the outer end portion of said third counterbore is interiorly threaded and said nut is exteriorly threaded.
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19. A joint as claimed in claim 17, in which said nut is interiorly threaded and in which the end portion of said body member is exteriorly threaded.
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20. A joint as claimed in claim 16, in which said antifriction ring is coated with a dry film antifriction lubricant material.
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21. A joint as claimed in claim 1 in which each inner and outer end wall of said annular recess means has a radius at its outer and inner junctures.
Specification