Spiral tractor apparatus and method
First Claim
1. A spiral pig apparatus for axial movement through a pipe of the type having a cylindrical interior surface defining a central axis, said spiral pig apparatus comprising:
- (a) a first section;
(b) a second section, coupled to said first section for axial movement therewith and for relative rotation with respect to said first section;
(c) a first plurality of wheels attached to said first section, each of said first plurality of wheels attached at a first rolling angle relative to said pipe axis for rolling contact with said interior surface of said pipe and for supporting said first section spaced inward from said interior surface of said pipe;
(d) a second plurality of wheels attached to said second section, each of said second plurality of wheels attached at a second rolling angle relative to said pipe axis for rolling contact with said interior surface of said pipe, which second rolling angle is different from said first rolling angle of said first set of wheels, and said second plurality of wheels also attached for supporting said second section spaced inward from said interior surface of said pipe; and
(e) a drive mechanism operatively connected to said spiral pig for causing said pig to move through said pipe as said first and second sections rotate relative to each other.
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Accused Products
Abstract
A spiral pig apparatus is provided for axial movement through a pipe of the type having a cylindrical interior surface defining a central axis. The spiral pig apparatus includes a first and a second section coupled to each other for axial movement of both sections and for relative rotation between the first and second sections. A first plurality of wheels is attached to the first section. Each of the first plurality of wheels is attached at a first rolling angle, relative to the pipe axis for rolling contact with the interior surface of the pipe, and for supporting the first section spaced inward from the interior surface of the pipe. A second plurality of wheels is attached to the second section. Each of the second plurality of wheels is attached at a second rolling angle, relative to the pipe axis for rolling contact with the interior surface of the pipe. The second rolling angle is different from the first rolling angle of the first set of wheels. The second plurality of wheels is also attached for supporting the second section spaced inward from the interior surface of the pipe. A drive mechanism is operatively connected to the spiral pig for causing the pig to move through the pipe, as the first and second sections rotate relative to each other.
157 Citations
17 Claims
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1. A spiral pig apparatus for axial movement through a pipe of the type having a cylindrical interior surface defining a central axis, said spiral pig apparatus comprising:
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(a) a first section; (b) a second section, coupled to said first section for axial movement therewith and for relative rotation with respect to said first section; (c) a first plurality of wheels attached to said first section, each of said first plurality of wheels attached at a first rolling angle relative to said pipe axis for rolling contact with said interior surface of said pipe and for supporting said first section spaced inward from said interior surface of said pipe; (d) a second plurality of wheels attached to said second section, each of said second plurality of wheels attached at a second rolling angle relative to said pipe axis for rolling contact with said interior surface of said pipe, which second rolling angle is different from said first rolling angle of said first set of wheels, and said second plurality of wheels also attached for supporting said second section spaced inward from said interior surface of said pipe; and (e) a drive mechanism operatively connected to said spiral pig for causing said pig to move through said pipe as said first and second sections rotate relative to each other. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A spiral pig apparatus for axial movement through a pipe of the type having a cylindrical interior surface defining a central axis, said spiral pig apparatus comprising:
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(a) a first section having a plurality of wheels attached thereto and spaced circumferentially therearound for rolling contact with said pipe interior, each of said first plurality of wheels positioned at a first predetermined rolling contact angle with respect to said pipe axis; (b) a second section having a plurality of wheels attached thereto and spaced circumferentially therearound for rolling contact with said pipe, each of said second plurality of wheels positioned at a second predetermined rolling contact angle with respect to said pipe axis and which second predetermined rolling contact angle is different from said first predetermined rolling contact angle; and (c) a drive motor, coupled between said first and second sections for coaxially rotating said first section relative to said second section, so that said angled rolling contact of said first and second plurality of wheels at different relative angles to cause said pig to move axially through said pipe interior.
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Specification