Claims
- 1. The method of making a heat transfer element comprising:
- a. forming an elongated tubular member having a wall portion and a longitudinal center line therein,
- b. successively, from one end portion of said tubular member toward the other end portion thereof,
- (1) making cuts into said wall portion with a cutter means to thereby afford elongated fins extending across said tubular member in a direction transverse to the length thereof,
- (2) turning said fins outwardly into outwardly projecting relation to said tubular member, and
- c. predeterminedly severing with said cutter means certain of said fins from said wall prior to making the next successive cut into said wall to provide at least two groups of fins spaced from each other longitudinally along said wall portion with the spacing therebetween formed by the severed fins stubs having substantially a horizontal outer plane surface with signed to the longitudinal center line of said tubular member.
- 2. The method of making a heat transfer element comprising
- a. forming an elongated tubular member having a longitudinal center line therein and top and bottoms wall portions thereon,
- b. successively, from one end portion of said tubular member toward the other end portion thereof,
- (1) making cuts into said top and bottom wall portions with a cutter means thereby providing elongated fins extending across said tubular member in a direction transverse to the length thereof,
- (2) turning said fins longitudinally outwardly into projecting relation to said tubular member wherein said fins are convexly curved toward said other end portion, and
- c. predeterminedly severing with said cutting means certain of said fins from said top and bottom wall portions at the end of making the cut forming each respective one of said last mentioned fins to provide at least two groups of fins spaced from each other longitudinally along both of said top and bottom walls, with the spacing therebetween formed by the severed fins stubs having substantially an outer horizontal plane surface with respect to the longitudinal center line of the tubular member.
- 3. The method defined in claim 2, and in which
- a. said tubular member is longitudinally moving in a direction toward said one end portion at all times.
- 4. The method defined in claim 3, and in which
- a. said fins are severed by cutting outwardly away from said wall portion.
- 5. The method defined in claim 1 further including the steps of positioning a tubular steel pipe in sealingly relationship in said tubular member to complete the heat transfer element.
- 6. The method defined in claim 3, and which includes
- a. reducing the outer diameter size of the end portions of said tubular member extending outwardly of said upwardly turned fins by making successive cuts into said end wall portions at a uniform distance from the longitudinal center line of said tubular member and predeterminedly severing with said cutting means the upwardly turned fins at the end of making the cut.
- 7. The method defined in claim 3, and which includes
- a. forming end portions at opposite ends of said tubular member, each of which end portions has an outer portion, the outer surface of which is substantially parallel to the center line of said tubular member, and an inner portion, the outer surface of which slopes inwardly from said outer portion of the respective end portion toward said center line, by
- (1) failing to make said cuts on said outer portions and the trailing one of said inner portions, and
- (2) making said fin-severing cuts, at progressively shorter distances away from said center line, along the leading one of said inner portions.
- 8. The method defined in claim 3, and which includes
- a. forming end portions at opposite ends of said tubular member, each of which end portions has sn outer portion, which is of reduced thickness and the outer surface of which is substantially parallel to the center line of said tubular member, and an inner portion, the outer surface of which slopes inwardly from said outer portion of the respective end portion toward said center line, by
- (1) making said fin-severing cuts on said outer portions at a uniform distance from said center line,
- (2) making said fin-severing cuts, at progressively shorter distances away from said center line, along the leading one of said inner portions, and
- (3) failing to make said fin forming cuts and said fin-severing cuts on the trailing one of said inner portions.
Parent Case Info
This is a division of application Ser. No. 386,950, filed June 10, 1982, now U.S. Pat. No. 4,554,970.
US Referenced Citations (6)
Divisions (1)
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Number |
Date |
Country |
Parent |
386950 |
Jun 1982 |
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