Method of roller spinning cup-shaped metal blanks
First Claim
1. In a method of making a cup-shaped sheet metal pulley blank of the type having a bottom wall and a connected outer cylindrical side wall terminating in an open end, from a flat sheet metal disc with pressure roll forming means, for use as a stage blank for forming a V-grooved pulley, including the steps of:
- a. providing a flat uniform thickness sheet metal disc having a central hole formed therein;
b. clamping a central portion of the disc around the hole between opposed relatively axially movable complementary clamping faces of rotatable headstock and tailstock die means wherein the headstock die means also has cylindrical flange-forming means and reentrant conical flange forming means connected with the cylindrical flange forming means by a reentrant corner acutely angled in cross section;
c. rotating the die means and clamped disc;
d. reforming the disc into a cup-shaped blank having a flat bottom wall and a connected annular reversely angled conical flange portion terminating in an axially extending open-ended cylindrical side wall portion by pressure rolling, forming and ironing the rotating annular disc metal portions surrounding said central portion against the headstock die means cylindrical and conical flange forming means and the connected reentrant corner;
2 Assignments
0 Petitions
Accused Products
Abstract
A method of making a dynamically balanced cup-shaped blank for use in the production of a V-grooved pulley, from a flat sheet metal disc by a roller spinning tool. The disc is provided with a central hole for mounting the disc on rotating die means between headstock and tailstock die form assemblies of a spinning machine. The spinning tool presses the disc against an end of a headstock die form and moves generally radially outwardly pressing a portion of the disc against the end of the die form to provide a bottom wall of the desired cup-shaped blank. The spinning tool then moves in a series of passes along the headstock die form thereby rolling, forming and ironing rotating outer metal portions of the disc against the die, and forming the disc with an annular reversely angled conical flange and an axially extending cylindrical side wall which terminates in an open end. The die form and spinning tool also form a reentrant corner in the disc blank which connects the conical flange with the cylindrical wall and which is defined by an acute angle with the cylindrical side wall. The conical flange ultimately forms a portion of one of the flanges of a V-groove in a finished pulley subsequently spun from the cup-shaped stage blank. The open end of the cylindrical side wall then is trimmed to a predetermined length to provide the desired wall length in which one or more V-grooves will be spun, to form a finished dynamically balanced, spun V-grooved pulley.
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Citations
11 Claims
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1. In a method of making a cup-shaped sheet metal pulley blank of the type having a bottom wall and a connected outer cylindrical side wall terminating in an open end, from a flat sheet metal disc with pressure roll forming means, for use as a stage blank for forming a V-grooved pulley, including the steps of:
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a. providing a flat uniform thickness sheet metal disc having a central hole formed therein; b. clamping a central portion of the disc around the hole between opposed relatively axially movable complementary clamping faces of rotatable headstock and tailstock die means wherein the headstock die means also has cylindrical flange-forming means and reentrant conical flange forming means connected with the cylindrical flange forming means by a reentrant corner acutely angled in cross section; c. rotating the die means and clamped disc; d. reforming the disc into a cup-shaped blank having a flat bottom wall and a connected annular reversely angled conical flange portion terminating in an axially extending open-ended cylindrical side wall portion by pressure rolling, forming and ironing the rotating annular disc metal portions surrounding said central portion against the headstock die means cylindrical and conical flange forming means and the connected reentrant corner; - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11)
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2. e. said reforming step including forming a reentrant corner, acutely angled in cross section, connecting said reversely angled conical flange and said axially extending side wall portion;
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f. maintaining the thickness of the disc metal during reforming throughout the conical flange portion, the reentrant corner and cylindrical wall portions substantially unchanged from that of the sheet metal disc to provide a cup-shaped blank having substantially uniform thickness conical flange portion, reentrant corner and cylindrical side wall portion; and g. then while continuing rotation of the die means and clamped blank, trimming the open end of the cylindrical side wall to predetermined axial length with respect to the acutely angled reentrant corner.
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Specification