System for forming end flanges on pipes
AssigneeBend All Manufacturing Inc.
InventorHorst U. Petersen
Life of this patent
Estimating the term…
Abstract
The system increases the diameter to which pipe flanges can be flared. The tendency of the radial wall of the flange to crumple inwards is obviated by coining the transition corner of the wall. First, the pipe end is belled out to provide access for the coining punch. The belled-out end is then swaged back in, after the punch is removed. With the corner transition thus preconditioned, further axial pressure on the pipe with a suitable female punch causes the flange to expand diametrally in a controllable manner.
Claims8
Procedure for producing an enlarged end-flange on a pipe, being an end-flange which includes front and back radially-extending walls formed in the material of the pipe, the walls being opposed in that the front wall faces towards the end of the pipe and the back wall faces away from the end of the pipe, and which includes an endmost-portion of the end-flange, the endmost-portion being cylindrical and of approximately the same diameter as the nominal diameter of the pipe, wherein:
- the end-flange of the pipe is of the type in which, inside the end-flange, the front wall is axially spaced from, and out of contact with, the back wall;
- the procedure includes the steps of clamping the pipe in a female die, leaving an end-portion of the pipe protruding from the die, the die having an inner surface complementary to the pipe, having a surface facing the end of the pipe, and having a transition corner therebetween;
- belling-out the protruding end-portion of the pipe, creating a transition between the belled end-portion and the portion of the pipe gripped in the female die;
- providing a male punch, having a nose, a shoulder of greater diameter than the nominal inside diameter of the pipe, and having a transition corner between the shoulder and the nose;
- with the male punch inside the belled end-portion, pushing the male punch far enough axially, that the wall material of the pipe, at the said transition, is coined between the transition corner of the die and the transition corner of the punch;
- withdrawing the male punch, leaving the pipe with the whole length of the end-portion belled;
- reducing the diameter of a endmost-portion of the belled end-portion, being less than the whole length of the end-portion, leaving an inner-length-portion of the belled end-portion not reduced;
- while constraining the length of the endmost-portion against diametral expansion and with the interior of both the endmost-portion and inner-length-portion being unsupported, pushing axially on the pipe to the extent that the inner-length-portion of the end-portion buckles or collapses, and increases in diameter, thereby creating the said front and back walls;
- ceasing pushing axially on the pipe before the front wall touches the back wall internally, and while the front and back walls are still internally spaced apart in the axial sense.
Apparatus for producing an enlarged end-flange on a pipe, being an end-flange which includes front and back radially-extending walls formed in the material of the pipe, the walls being opposed in that the front wall faces towards the end of the pipe and the back wall faces away from the end of the pipe, and which includes an endmost-portion of the end-flange, the endmost-portion being cylindrical and of approximately the same diameter as the nominal diameter of the pipe, wherein:
- the end-flange of the pipe is of the type in which, inside the end-flange, the front wall is axially spaced from, and out of contact with, the back wall;
- the apparatus comprises:
- a female die, having a means for clamping the pipe, leaving an end-portion of the pipe protruding from the die, the die having an inner surface complementary to the pipe, having a surface facing the end of the pipe, and having a transition corner therebetween;
- an operable means for belling-out the protruding end-portion of the pipe, which is effective to create a transition between the belled end-portion and the portion of the pipe gripped in the female die;
- a male punch, having a nose, a shoulder of greater diameter than the nominal inside diameter of the pipe, and having a transition corner between the shoulder and the nose;
- an operable means for pushing the male punch, with the male punch inside the belled end-portion, far enough axially that the wall material of the pipe, at the said transition, is coined between the transition corner of the die and the transition corner of the punch;
- an operable means for withdrawing the male punch, leaving the pipe with the whole length of the end-portion belled;
- an operable means for reducing the diameter of an endmost-portion of the belled end-portion, being less than the whole length of the end-portion, which is effective, when operated, to leave an inner-length-portion of the belled end-portion not reduced;
- an operable means for pushing axially on the pipe, which is forceful enough, when operated, and while constraining the length of the endmost-portion against diametral expansion, that the inner-length-portion of the end-portion buckles or collapses, and increases in diameter without support for the interior of both the endmost-portion and the inner-length-portion, thereby creating the said front and back walls;
- an operable means for withdrawing the means for pushing axially on the pipe, which is operable before the front wall touches the back wall internally, and while the front and back walls are still internally spaced apart in the axial sense.
Dependencies are inferred from the claim text.