Patent US3753363A successfully refreshed from Google Patents.
US3753363A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helically wound tubing
Assignee: Johns Manville Corp
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Filing: 1971-04-07
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Granted: 1973-08-21
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Expires: 1991-04-07
Abstract
Abstract A locked seam is formed in ducting formed by convoluted metal strip and seam locking adjacent edges of adjacent convolutions, in which one edge is folded to form a pair of inwardly facing channels and the other is folded to form a generally T-shaped flange and the arms of the T-shaped flange are locked within the channels. The seam may be formed by folding the edges of the strip before it is convoluted to provide along one edge an open U-shaped element facing out of the plane of the strip. A complementary flange is formed along the other edge, generally of similar U-shape or L-shape and after the strip is convoluted and the edges are mated the U-shape is deformed to form the seam. Apparatus for forming the seam comprises a mandrel removably mounted on a frame and two pairs of forming means disposed about the mandrel, one pair being fixed in its location relative to the frame and the other pair being movable with the mandrel, whereby the mandrel can be changed without requiring adjustment of the forming means.
Inventors
- 👤 Trihey J Massey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:32
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/156; B21C37/157; B21C37/12; B21C37/121; B21C37/124
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
119 words
Apparatus for forming helically wound tubing from ductile strip material comprising: a frame, a mandrel mounted on the frame but removable therefrom, and forming means located about the periphery of the mandrel for seaming together adjacent edges of strip material convoluted about the mandrel and characterized in that the forming means comprise two co-operating pairs of forming means with one pair being mounted on the frame and the other pair being mounted to be removable with the mandrel whereby on substitution of a new mandrel of one size for another mandrel the one pair of forming means is compatible with either mandrel and only the other pair of forming means needs to be adjusted to accommodate the new mandrel.
Claim 2
Dependent Claim
119 words
Apparatus for forming helically wound tubing from ductile strip material comprising: a frame, a mandrel mounted on the frame but removable therefrom, and forming means located about the periphery of the mandrel for seaming together adjacent edges of strip material convoluted about the mandrel and characterized in that the forming means comprise two co-operating pairs of forming means with one pair being mounted on the frame and the other pair being mounted to be removable with the mandrel whereby on substitution of a new mandrel of one size for another mandrel the one pair of forming means is compatible with either mandrel and only the other pair of forming means needs to be adjusted to accommodate the new mandrel.
Claim 3
Dependent Claim
47 words
Apparatus as claimed in claim 1, wherein said other pair of forming means comprises a first forming element constituted by the mandrel, and a second element arranged to co-operate with said first element and said second element being mounted on the mandrel for removal with the manrel.
Claim 4
Dependent Claim
39 words
Apparatus as claimed in claim 2, wherein the mandrel is a fixed substantially cylindrical mandrel and said one pair of forming means comprises a pair of rollers one of which is located in a cavity formed in the mandrel.
Claim 5
Dependent Claim
25 words
Apparatus as claimed in claim 1, wherein there is further provided spiking means to spike the strip before the strip is fed to the mandrel.
Claim 6
Dependent Claim
45 words
Apparatus as claimed in claim 4, wherein the spiking mechanism comprises a spiked roller arranged on one side of the strip and a backing roller arranged on the other side of the strip to support the strip as it is spiked by the spiking roller.
Claim 7
Dependent Claim
66 words
Apparatus as claimed in claim 4 wherein the spikes are tapered spikes and means is provided to vary the position of the spiking means relative to the strip to render it operative or inoperative and to vary the degree of penetration of the strip by the spikes thereby varying the size of holes formed by the spikes when the spiking mechanism is in an operative position.
Claim 8
Dependent Claim
48 words
Apparatus as claimed in claim 1 wherein said other pair of forming means comprises a first forming element constituted by a roller mounted within the mandrel, and a second element arranged to co-operate with the said first element and mounted on the mandrel for removal with the mandrel.
Claim 9
Dependent Claim
39 words
Apparatus as claimed in claim 7, wherein the mandrel is a fixed substantially cylindrical mandrel and said one pair of forming means comprises a pair of rollers one of which is located in a cavity formed in the mandrel.
Claim 10
Dependent Claim
39 words
Apparatus as claimed in claim 1, wherein the mandrel is a fixed substantially cylindrical mandrel and said one pair of forming means comprises a pair of rollers one of which is located in a cavity formed in the mandrel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |