This invention relates generally to methods and machines for manufacturing fluted filter media, and more particularly to a method and apparatus for winding a fluted media into a coreless roll.
Spiral wound fluted filter media are well known. Cylindrical fluted filter elements are typically made by winding fluted media about a central mandrel. The mandrel is manually connected to the leading edge of the media and then rolled to wind the media around it. The mandrel is typically left inside the media to plug the center. Connecting the mandrel to the leading edge is labor intensive. The mandrel at times also does not seal reliably to the media in contact with it, providing an undesirable leak path. Using a separate mandrel for each media also adds cost.
Another prior art approach is shown in U.S. Pat. Nos. 5,543,007 and 5,435,870. In that approach, one or more releasable xe2x80x9cclawsxe2x80x9d grip a front edge of the media, the media is rolled around the claws, and then the claws are removed. This approach is also labor intensive in that the claws must be attached and then removed when making each filter. The claw also interferes with the bead of sealant that must be applied on the media, which can result in the claw becoming undesirably glued to the media and, upon removal, possible tears or poor sealing of the media. Claws or other removable mandrels also add complexity in that they require a special means for releasing them from the media. They also add cost in that the opening left behind must be filled with special materials to create a core and provide sealing.
It can be seen that a new apparatus and method is needed for winding a fluted media into a coreless roll without the use of a temporary or permanent mandrel, thereby reducing or eliminating the shortcomings of the prior art discussed above.
In the invention, the use of a mandrel that grips the front end of the media in order to wind the media around it is eliminated. In addition to the manufacturing cost and other benefits associated with eliminating the mandrel, the invention also results in a complete and reliable seal of the center portion of the wound media.
In one aspect of the method of the invention, a fluted media having flutes with a first end that is closed and a second end that is open, is wound into a coreless roll. The fluted media is sealed transversely across the front end. A sealant is applied on top of the fluted media along a side edge adjacent the second end of the flutes. As the fluted media is transported forwardly, its front edge is lifted upwardly, without gripping, so as to bend the fluted media rearward of the front edge. The front edge is then pushed, without gripping, rearwardly and then downwardly to form an incipient log, or roll start. The remaining portion of the fluted media is rolled around the incipient log, and the back end is sealed to the roll.
In one aspect of the apparatus of the present invention, the apparatus comprises a transport arrangement that moves the fluted media forwardly and structure that facilitates forming an incipient log around which a remaining portion of the fluted media can be rolled. The structure includes a generally rearwardly facing inclined ramp that lifts a front edge of the fluted media upwardly, a generally rearwardly facing surface that then pushes it rearwardly, and a generally downwardly facing surface that then pushes the front edge downwardly. As will be discussed further below, this structure can be any of a number of different configurations within the principles of the invention to achieve winding a fluted media into a coreless roll without the use of a mandrel.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto. However, for a better understanding of the invention and its advantages, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.