Winding device for multiple bobbins (tub variant) on sewing machines

Abstract

A winding device for feeding sewing thread from at least two bobbins to a sewing machine, in particular an overlock or coverlock machine, characterized in that it comprises: (a) a base plate with a receiving opening for detachable attachment to a bobbin holder or thread disc of the sewing machine, (b) at least two winding units in the form of trays, each forming a receiving space adapted to the outer contour of the bobbin, wherein the bobbin is mounted in the respective tray to be rotatably axially free with radial and axial play, and (c) at least one thread guide element, which is positioned in such a way as to ensure that the thread is taken off the bobbins in a substantially vertical manner.

Description

Technical field

[0001] The invention relates to sewing machine accessories and is based on a device for unwinding and feeding sewing threads from multiple bobbins for sewing machines with multiple thread feeds, in particular overlock and coverlock machines. The device is designed as an adapter for mounting on the existing bobbin holder or thread disc of the machine. State of the art and initial problem

[0002] Overlock and coverlock machines are typically operated with two to five thread feeders, for which several spools of thread of the same color are usually purchased (due to cost and leftover thread issues). Rewinding a single spool of thread onto multiple bobbins is possible; however, a device that feeds multiple bobbins properly, safely, and without preserving the twist directly at the machine is lacking. Task

[0003] Provision of a compact, retrofittable adapter device that securely accommodates at least two bobbins, allows their unwinding around a longitudinal axis substantially parallel to the base plate, and ensures substantially vertical thread take-up without affecting twisting and thread tension. Summary of the invention

[0004] The device comprises a base plate with a receiving opening for detachable attachment to the bobbin holder or thread disc of the sewing machine, and at least two unwinding units in the form of trays (cups / troughs), each holding a bobbin. Each tray forms a bobbin-shaped receiving space whose contour corresponds to the outer contour of the bobbin, but with radial and axial play so that the bobbin can rotate axially in place; the axis of rotation runs essentially parallel to the base plate. A securing element (e.g., a circumferential rim, clip, cap, or bracket) prevents unintentional removal. Optionally, one or more thread guides are arranged so that the thread is pulled off the bobbins essentially vertically and introduced into the machine's thread guide. Designs (without drawings) - Arrangement / number of trays: at least two; preferably three to six; radially around the receiving opening or linearly in a row. - Tub inner contour: adapted to bobbin shape; radial / axial with play tolerance for smooth rotation. - Friction reduction: smooth inner surfaces; optional liner / bearing sleeve or coating (PTFE / POM / PA, sintered bronze insert rings) as sliding bearings. - Securing element: circumferential rim, elastic clip, cover cap or bail; optionally spring-loaded. - Thread guide: central eyelet / guide pin / bail; optional local guides per tub; preferably height-adjustable. - Mounting / adaptation: Cylindrical / conical mounting opening; adapter inserts / clamping devices for various spool holder diameters; base plate preferably not held in a rotating position. - Materials: Plastic (injection molding / 3D printing), metal or composite; low friction inner layer. Advantages

[0005] Parallel operation of multiple thread feeds from a rewound yarn spool; cost reduction and waste reduction; twist-preserving take-up thanks to axially rotating bobbins in troughs; easy retrofitting without intervention in the machine.

Claims

[1] Unwinding device for feeding sewing thread from at least two bobbins to a sewing machine, in particular an overlock or coverlock machine, characterized by , comprising: (a) a base plate with a receiving opening for detachable attachment to a bobbin holder or thread disc of the sewing machine, (b) at least two unwinding units in the form of trays, each forming a receiving space adapted to the outer contour of the bobbin, the bobbin being axially rotatable in the respective tray with radial and axial play, and (c) at least one thread guide element positioned to ensure substantially vertical thread take-off from the bobbins. [2] Device according to claim 1, wherein each tub has a securing element in the form of a circumferential rim, a clip, a cover cap or a bracket to prevent the bobbin from unintentionally falling out. [3] Device according to one of the preceding claims, wherein the inner surface of the tub has a sliding layer or a liner / bearing sleeve made of PTFE, POM, PA, a composite layer or sintered bronze. [4] Device according to one of the preceding claims, wherein the trays are arranged radially around the receiving opening of the base plate. [5] Device according to claims 1-3, wherein the tubs are arranged linearly in series. [6] Device according to one of the preceding claims, wherein the thread guide element is height-adjustable. [7] Device according to one of the preceding claims, wherein the receiving opening is cylindrical or conical and / or has adapter inserts for adapting to different coil holder diameters. [8] Device according to one of the preceding claims, wherein the underside of the base plate has a friction lining for stable contact on the yarn disc. [9] Device according to one of the preceding claims, wherein at least three tubs are provided. [10] Device according to one of the preceding claims, wherein the tubs are attached to the base plate by plugging or screwing. [11] Device according to one of the preceding claims, in which, in addition, a local thread guide element is arranged between the bobbin and the thread guide element according to claim 1 in each tub. [12] Device according to one of the preceding claims, wherein the base plate and / or trays are made of plastic, metal or a composite material. [13] Device according to one of the preceding claims, wherein the inner contour of the tub has interchangeable inserts for adapting to different bobbin shapes. [14] Device according to one of the preceding claims, wherein the base plate is not rotatably held on the spool holder or yarn disc.