US3982778A — Joint and process for forming same

Claim 1

Independent Claim 174 words

An improved flange-tube joint comprising a flange formulated by placing a mixture of powdered metal and a lubricant in a flange shaped mold, compressing the mixture at a pressure of at least about 4 × 10 7 Kg. per sq. meter in said mold, removing the resulting flange from the mold, initially heating the flange in a non-oxidizing gas atmosphere at a temperature which falls within the range from about 500° C to about 1200° C to remove the lubricant, further heating the flange at a temperature which falls within the range from about 800° C to about 1500° C, cooling the flange to a temperature of no more than about 100° C and dry machining an annular channel into said flange; and a tube having an external diameter nearly equal to the diameter of said hole, one end of said tube being within said hole, said tube being formulated of a less hard metal than said flange, the external surface of said tube being expanded into said channel to thereby form said joint.

Claim 2

Dependent Claim 174 words

An improved flange-tube joint comprising a flange formulated by placing a mixture of powdered metal and a lubricant in a flange shaped mold, compressing the mixture at a pressure of at least about 4 × 10 7 Kg. per sq. meter in said mold, removing the resulting flange from the mold, initially heating the flange in a non-oxidizing gas atmosphere at a temperature which falls within the range from about 500° C to about 1200° C to remove the lubricant, further heating the flange at a temperature which falls within the range from about 800° C to about 1500° C, cooling the flange to a temperature of no more than about 100° C and dry machining an annular channel into said flange; and a tube having an external diameter nearly equal to the diameter of said hole, one end of said tube being within said hole, said tube being formulated of a less hard metal than said flange, the external surface of said tube being expanded into said channel to thereby form said joint.

Claim 3

Dependent Claim 53 words

A joint as in claim 1, wherein said flange, prior to the placing of said tube within said hole is contacted with steam in a substantially oxygen-free atmosphere at a temperature above about 340° C for at least 5 minutes and cooled after completion of said contacting and before formation of said joint.

Claim 4

Dependent Claim 54 words

An improved joint as in claim 2, wherein said first heating is carried out at a temperature which falls within the range from about 750° C to about 1000° C and said further heating step is carried out at a temperature which falls within the range from about 1025° C to about 1225° C.

Claim 5

Dependent Claim 54 words

A joint as in claim 3, wherein said initial heating step is carried out for a time which falls within the range from about 5 minutes to about 40 minutes and said further heating step is carried out for a time which falls within the range from about 10 minutes to about one hour.

Claim 6

Dependent Claim 37 words

A joint as in claim 3, wherein said contacting with steam is carried out at a temperature which falls within the range from about 340° C to about 650° C for at least about one half hour.

Claim 7

Dependent Claim 46 words

A joint as in claim 5, wherein said contacting with steam is carried out at a temperature which falls within the range from about 540° C to about 600° C for a time which falls within the range from about 1 hour to about 2 hours.

Claim 8

Dependent Claim 21 words

A joint as in claim 6, wherein said annular channel is dry machined into said flange prior to said contacting step.

Claim 9

Dependent Claim 225 words

In a process for forming a force-fit tubing-flange joint comprising providing a metallic flange having a circular cross-section hole therethrough adapted to matingly receive a metallic tube, said hole including an annular channel extending therefrom into said flange, placing within said hole one end of said tube, said end having an external diameter nearly equal to the diameter of said hole, said tube being formulated of a less hard metal than said flange, and forcing an expander into said one end of said tube to force said tube to expand into said annular channel thereby forming said force-fit joint, the improvement of increasing the torque strength of said joint comprising: formulating said flange by placing a mixture of powdered metal and a lubricant in a flange shaped mold, compressing the mixture at a pressure of at least about 4 × 10 7 Kg. per sq. meter in said mold, removing the resulting flange from the mold, initially heating it in a non-oxidizing gas atmosphere at a temperature which falls within the range from about 500° C to about 1200° C to remove the lubricant therefrom, further heating it at a temperature which falls within the range from about 800° C to about 1500° C, cooling it to a temperature of no more than about 100° C, and dry machining said annular channel into said flange.

Claim 10

Dependent Claim 225 words

In a process for forming a force-fit tubing-flange joint comprising providing a metallic flange having a circular cross-section hole therethrough adapted to matingly receive a metallic tube, said hole including an annular channel extending therefrom into said flange, placing within said hole one end of said tube, said end having an external diameter nearly equal to the diameter of said hole, said tube being formulated of a less hard metal than said flange, and forcing an expander into said one end of said tube to force said tube to expand into said annular channel thereby forming said force-fit joint, the improvement of increasing the torque strength of said joint comprising: formulating said flange by placing a mixture of powdered metal and a lubricant in a flange shaped mold, compressing the mixture at a pressure of at least about 4 × 10 7 Kg. per sq. meter in said mold, removing the resulting flange from the mold, initially heating it in a non-oxidizing gas atmosphere at a temperature which falls within the range from about 500° C to about 1200° C to remove the lubricant therefrom, further heating it at a temperature which falls within the range from about 800° C to about 1500° C, cooling it to a temperature of no more than about 100° C, and dry machining said annular channel into said flange.

Claim 11

Dependent Claim 53 words

An improved process as in claim 8, wherein said first heating step is carried out at a temperature which falls within the range from about 750° C to about 1000° C and said further heating step is carried out at a temperature within the range from about 1025° C to about 1225° C.

Claim 12

Dependent Claim 56 words

An improved process as in claim 9, wherein said initial heating step is carried out for a time which falls within the range from about 5 minutes to about 40 minutes and wherein said further heating step is carried out for a time which falls within the range from about 10 minutes to about 1 hour.

Claim 13

Dependent Claim 55 words

An improved process as in claim 10, including as an added step: contacting said flange, prior to the placing of said tube in said hole, with steam in a substantially oxygen-free atmosphere at a temperature above about 340° C for at least about 5 minutes; and cooling said flange after completion of said steam contacting.

Claim 14

Dependent Claim 37 words

An improved process as in claim 11, wherein said steam contacting is carried out at a temperature which falls within the range from about 340° C to about 600° C for at least about one half hour.

Claim 15

Dependent Claim 45 words

An improved process as in claim 12, wherein said contacting is carried out at a temperature which falls within the range from about 540° C to about 600° C for a time which falls within the range from about 1 hour to about 2 hours.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-09-28	1980-03-29	1980-09-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-09-28	1984-03-29	1984-09-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-09-28	1988-03-29	1988-09-28	$7700.00	Window Closed / Lapsed

Joint and process for forming same

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