The subject application discloses improved tufting apparatus which utilizes basic concepts from tufting techniques disclosed in U.S. Pat. No. 3,554,147 which issued to Abram N. Spanel and George J. Brennan on Jan. 12, 1971 and U.S. Pat. No. Re27,165 which issued Aug. 10, 1971 to Abram N. Spanel and Loy E. Barton.
The aforementioned U.S. Pat. No. Re27,165 discloses a pneumatic yarn transport system in which yarn is transported pneumatically to a tufting station where it is applied by tufting elements to a backing layer. Multi-color selection of the yarn is provided and for each needle station, there may be color choices of five, eight or any reasonable number of colors.
The aforementioned U.S. Pat. No. 3,554,417 describes an alternative system to U.S. Pat. No. Re27,165 and provides for the simultaneous selection of bit-lengths of yarn of various colors for each tufting cycle at each individual tufting station. A collator structure is utilized in which individual channels transport yarn into a common passageway adjacent the tufting station. In a preferred embodiment, the severing function takes place in close proximity to the tufting station after a selected yarn strand has been fed into the common passageway.
It is desirable in complex machinery such as the Spanel apparatus to not have to shift locations of major mechanisms. Accordingly, it is desirable to keep the cutting mechanism and the tufting elements in set locations, however, when this is done, the ability to obtain variable size products is reduced unless compensating adjustability mechanisms are provided.
In the preferred embodiment of the subject case, a yarn strand is pneumatically fed so as to extend past a yarn severing mechanism to dual tufting needles. The yarn strand is severed so that a yarn bit is loaded with it being desired that equal yarn lengths extend to the right and left of the dual needle which has its shanks in close proximity one to another. When the yarn bit is then tufted, equal tuft legs of a U-shaped tuft will be obtained.
It will be appreciated that if the yarn severing means is 1 inch from the tufting needles, then a bit-length of yarn of 2 inches will provide a tuft with approximately 1-inch legs (not counting the portion of yarn between tufting needles when dual needles are utilized). If 2-inch legs are desired, which means a bit-length of yarn of approximately 4 inches, must be provided, then it is obvious that if the severing means remains at the 1-inch distance from the tufting needles, one tuft leg will be 1 inch while the other tuft leg will be 3 inches, unless the yarn on each side of the tufting needles is equalized. Accordingly, yarn adjustment means to compensate for the above problems is desirable if selectability of different size tufts is to be a feature of such a tufting unit as above described.