A center made from molded thermoplastic resin on which yarn is wound, with a means for anchoring the yarn end

Abstract: It is necessary for yarn (F) which is wound into packages (R) on supports or centers (1) and is intended to be dyed, or at any rate subsequently employed for other uses, to be able to form, on an annular zone (16) at the sides of the support (1), a number of turns of "reserve" yarn available and intended for joining to the yarn of a subsequent package; in order to fasten the yarn end, a guide notch (3) is formed in the edge of said annular zone (16) and is combined with a portion (9) of very little thickness which can be torn by the yarn (F) which is inserted and forced into said notch (3) such that it becomes wedged in the tear and is held therein. This anchoring means may be provided in either the base or the top of the center (1) or in both the base and the top of the center (1) in order to fasten both ends of the wound yarn (F).

Description: It is well known that cylindrical, conical or frustoconical centers on which yarn is wound to form packages intended to undergo subsequent processes - dyeing, warping, weaving or other uses - are usually provided with an annular zone on one or both ends of the center, this annular zone being used to wind a number of turns of "reserve" yarn available and intended for joining to the yarn of a subsequent package; currently, the reserve yarn end is fastened somewhat precariously using random means which are rather impractical and unreliable, see for example US 3 955 775 A which corresponds to the preamble of claim 1 . The invention aims to solve this problem in an extremely satisfactory way. The above mentioned problem is solved by a yarn center according to claim 1. Further embodiments are defined in dependent claims 2 and 3. The invention will be more easily understood by reading the description and examining the attached drawing which shows a practical, nonlimiting example of the invention. In the drawing: Fig. 1 shows a very general view of a non-stackable center for yarn packages; Fig. 2 shows an enlarged detail of the zone indicated by the arrow II in Fig. 1; Fig. 3 shows a section on the line III-III in Fig. 2; Figs 4 and 5 show the same detail in a sectional view on IV-IV in Fig. 2 and in a view similar to the one in Fig. 3 once the yarn has been inserted and is held in the tear formed by it; Fig. 6 shows an enlarged detail from Fig. 4, before the tear is made. In the drawing the center, which is indicated as a whole by the reference numeral 1 in Fig. 1, has two ends 1A and 1B, on one or both of which may be formed a reserve of a number of turns of yarn, which represent the beginning of the yarn package, indicated as a whole by the letter R in Fig. 1. It must be possible to grip the beginning of this reserve yarn, or in any case the end of the yarn of the package R, by some suitable means in order to prevent said yarn end from coming undone, which is very easily done in the case of turns of reserve yarn which are exposed since they are wound separately on the end of the center. In order to grip the yarn end, a means is provided along the terminal edge of the end of the center, as illustrated in particular in Figs 2 to 6, which show a detail of the end 1B. For this purpose a transverse notch 3 is made, beginning in the terminal edge of the end 1B, preferably in the region of a shallow recess 5 formed on the inside of said edge. Next to said notch 3, on the outside of the edge, there is a deep recess 7 which in the drawing has a triangular shape when viewed head-on and whose bottom edge may slope toward the notch 3 and communicates with the tip of said notch. Formed at the inside end of the notch 3 and at the base of the recess 7 is a thin diaphragm 9 whose thickness is locally very reduced, and which can be obtained easily by means of a molding process, accurately molding those surfaces which will face each other to give this thin diaphragm 9. The diaphragm 9 is formed transversely and symmetrically with respect to the notch 3, as may be clearly seen in particular in Fig. 3. The thin diaphragm 9 must be located at the tip of the notch 3. The diaphragm 9 is formed from the same thermoplastic material which is used to injection-mold the center, and must be thin enough that it can be torn by forcing the yarn against it. With this arrangement, the end of the yarn of the package, or rather the end of the reserve turns wound on the end 1B of the center, is inserted in the direction of the arrow f in Fig. 2 and then forced - holding it on both the inside and the outside - against the diaphragm 9, which is torn as a result of the forcing action, for example in the direction of the arrow fl in Fig. 5, on one or other side of the said diaphragm 9 starting from the tip of the notch 3; the tearing action produces two lips in the diaphragm 9 which can be seen in Figs 4 and 5; these lips are able to grip the yarn F securely enough to prevent the terminal turns of reserve yarn from coming undone or even to prevent the package from beginning to come undone, by gripping the yarn end between them. This means is produced using a simple molding operation to mold the center. It should be understood that the drawing shows only one example of the invention, given solely by way of practical demonstration, it being possible to vary the forms and arrangements thereof without thereby departing from the scope of the invention as defined in the claims.

Claims: A yarn center made from molded thermoplastic resin, on which yarn is wound into packages, said center having a yarn support body with at least one annular zone (1A; 1B) at one end thereof for winding turns of reserve yarn, said annular zone (1A; 1B) being provided with an edge and yarn holding means associated with said edge for holding the yarn; characterized in that said holding means include a guide notch (3) beginning in said edge of said annular zone (1A; 1B) and a diaphragm portion (9) of very little thickness made such that it can be torn by the yarn which is inserted and forced into said notch and into said diaphragm portion (9), said diaphragm portion being formed approximately transversely to said guide notch (3). The center as claimed in claim 1, characterized in that said diaphragm portion (9) of very little thickness extends out on either side of said guide notch. The center as claimed in claim 1 or 2, characterized in that said yarn support body has two lateral annular zones (1A; 1B) at both ends thereof, each annular zone being provided with holding means so as to hold the tail end and the head end of the yarn.

Inventors: BOTTARI MARCO, BOTTARI, MARCO
Applicants: BOTTARI MARCO, BOTTARI, MARCO
Application year: 1996
Main classification: B65H75
IPC codes: B65H75