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Publication numberUS354390 A
Publication typeGrant
Publication dateDec 14, 1886
Filing dateJul 10, 1886
Publication numberUS 354390 A, US 354390A, US-A-354390, US354390 A, US354390A
InventorsBenjamin F. Caldwell
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Benjamin f
US 354390 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

(No Model.)



No. 354,390. Patented Dec. 14, 1886.




SPECIPICATON foning part of Letters Patent No. 354,390,'dated December lf. 1886.

' To all whom it may concern:

bbent and' formed accnmding.M to my .invention- 2O i the accompanying drawings, in which;

. Figure'l is a perspective view of a blank for a section of stove-pipe having its edges for making the interlocking con'necting'g'oint or seam. Fig; 2 is a transverse sectional view of the blank brought into stove-pipe form and having the edges folded an'd in position prior to the folds being compres'sed to complete the connecting joint or seam, and Fig. 3 a'similar view showing the folds-compressed and the connecting joint or seam com'- plete. r w

In the manufactnrevof stovepipes which are cylindrical or of other form in cross-sec-4 tion the 'Sections are composedof rcctilinear blanks of Sheet metal having their vlongitndinal edges interlocked to form a connecting- 'seann This has been effected by various .35 joints prior to my invention; but I have devised a simple construction'of the longitudinal edges 'of the sheet metal pipe-b1ank,whereby 'after the blank is bronghtinto pipe formthe 'pecu'liar looking joint or-seam can be com,-

pleted'at any timeby simply pressing the folds thereof together by means of any suitableimplement. o

Where no solder or brazing is eniployed to complete the seams or joints in ordinary stovepipes,they'are sometimes completed by employing separate fastening devices passing through the folded edges of the pipe-Sections, or by folding and slot-ting one edge and providing the other edge wit-htongnes passing through the slots and bent down.

Instead of soldering or brazing or using Application filed July 10, 1886. Serial No. .692. (No model.)

separate fastenings'or tongue-aud-slot connections,`I employ the construction which I will now describe in detail.

One longitudinal edge of the` Sheet-metal blank is bent to form a fiange, 1, standing at.

an acute angle to the 'blank to formwhat might be termed a V-shaped edge, 1*, and the opposite longitndinal edge of the blank is first'folded upon itself to form a strip or flange, 27, parallel, or approximately so, to the body of the blank and in contact therewith, constitnting an edge of two thicknesses, such strip lor flange being then bent outward obliquelyhas at 3, to constitute a,V-shaped recess, 4, with the edge of the obliqrle strip or bend 3 formed into a pendent flange, 5. The blank so formed is brought into cylindrical or pipe form and the V-shapcd edge 1' en- -tercd into the-V-shaped recess 4 in such' manner that the flange 1 is approximately parallel to the obliquc bend 3, and the edge of said flange 1 bears against the base or angle 6, forming the flange .5 on the obliqne bend, all as shown in Fig. 2. The parts' are now in proper position to be pressedl together, and thereby interlocked, which can` be accomplished by any suitable contrivances, such as a mandrel and pressing-rollers. In pressing the'bends and fianges together the flangeof theoblique bend 3 passes under the flange 1 and between it and, the body of the blank at one edge, and the oblique bend 3 is pressed downwith the flange 1 into a plane snbst-antially parallel to` the plane of the pipelsection', the whole constituting a lock joint orv seam which cannot be separated except by 'extraordinary force.-

The blanks having their edges constructed as described, and shown in Fig. 1, can be kept in stock and the pipes 'subsequentlylproduced by the method set forth of bringing the folded parts together; or the V-shaped edge of the blank may be introdnced into theV-shaped recess 4,iwhen the parts will b'e temporarily held by the edge of the flange 1 bearingagainst the base or angle 6 of thev fiange 5 on the oblique bend 3, after-which the parts can be' pressed together at any timeto complete 'the lock-joint.

Having thus'describcd my invention, vwhat I claim is'- w As'an article of manufacture, a stove-pipe IOC having the interlock'ing jeinb or seam herein In testimony whereof Iaffix my signature in descrbed, the same eonsisting in having a fold, presenee of two wibnesses. 1, ab one edge resting upon a fold, 2, ab the other edge and between such fold, and a strip BENJAMIN F' CALDWELL' 5 orbed, 3, having aflange, 5, extending around Witnesses:

and under t-he fold 1, substantialy as den P. H. MOORE,

scribed. WM. H. STELLE.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3967430 *Nov 27, 1974Jul 6, 1976Knudson Gary ArtBuilding method
US7681297 *Sep 23, 2003Mar 23, 2010Met-Coil Systems CorporationDuct fastseam
US8459307 *Feb 2, 2010Jun 11, 2013Met-Coil System Corp.Duct fastseam
Cooperative ClassificationF16L9/02