Constant tensioning device
First Claim
1. A filter bag assembly comprising:
- a filter bag;
means connected to said filter bag for maintaining it under substantially constant tension, said means including a rotatably mounted cam having an axis of rotation, a cable at least partially trained around a surface of said can, and spring means urging said cam to rotate in a first direction;
said spring means exerting a varying spring force dependent upon the rotational position of the cam, said cable arranged with respect to said cam so that when the cam is in a first rotational position where the spring force is relatively high, the cable is tangent to the surface of said cam at a first distance from the axis of rotation of said cam, and when the cam is in a second rotational position where the spring force is relatively low, the cable is tangent to the surface of said cam at a second distance from the axis of rotation of said cam which is smaller than said first distance.
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Accused Products
Abstract
A tensioning device is disclosed for maintaining proper tension of a filter bag assembly. The device includes a rotationally mounted cam, a torsion spring urging the cam to rotate in one direction, and a cable trained around the cam opposing the force exerted by the spring. Due to the shape of the cam, the cable force may be exerted at continuously varying distances from the axis of rotation of the cam. The spring, cam, and cable are arranged such that when the spring exerts a relatively high force on the cam, the cable force is exerted a further distance from the axis than when the cam is in a rotational position such that spring force is relatively low. A substantially constant cable force is accordingly exerted. The device is secured between the filter bag and a supporting structure of a baghouse. Constant tension is maintained even if the bag changes in length as the varying spring force is compensated by the cable acting upon the cam at different points.
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Citations
18 Claims
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1. A filter bag assembly comprising:
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a filter bag; means connected to said filter bag for maintaining it under substantially constant tension, said means including a rotatably mounted cam having an axis of rotation, a cable at least partially trained around a surface of said can, and spring means urging said cam to rotate in a first direction;
said spring means exerting a varying spring force dependent upon the rotational position of the cam, said cable arranged with respect to said cam so that when the cam is in a first rotational position where the spring force is relatively high, the cable is tangent to the surface of said cam at a first distance from the axis of rotation of said cam, and when the cam is in a second rotational position where the spring force is relatively low, the cable is tangent to the surface of said cam at a second distance from the axis of rotation of said cam which is smaller than said first distance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A filter bag assembly comprising:
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a filter bag having a first end including a bag cap and an opposing second end, said bag cap having an opening therein; a first support structure; a second support structure; means for securing said second end of said filter bag to said second support structure; a frame secured to said bag cap and extending within said filter bag; a cam rotatably mounted to said frame; a torsion spring contected to said cam and said frame, said torsion spring urging said cam to rotate in a first direction providing a variable force dependent upon the rotational position of said cam; and a cable trained around said cam, one end of said cable extending through said opening in said bag cap and being secured to said first support structure, a second end of said cable being secured to the cam, said cable exerting a force upon said cam opposing the force exerted thereon by said torsion spring, said cam, cable, and torsion spring being arranged such that said filter bag is maintained under substantially constant tension even if it shrinks or elongates a predetermined amount. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification