Sewing machine thread control
AssigneeWillcox & Gibbs, Inc.
InventorCarl E. Lindquist
Life of this patent
Estimating the term…
Abstract
To control thread pull-off, particularly in high-speed industrial sewing machines, a rotatable element such as a roller pin is engaged with the bobbin, typically with the outside flange of the bobbin. The pin is rotated, upon spinning of the bobbin, and restrained from free rotation by a spring bearing against the pin. Preferably, the pin is formed with drum or bell-shaped ends, the spring being similar to a bobbin case retaining spring and bearing against a reduced diameter thereof, to provide for different diameters of engaging rotating surfaces between flange and pin, as well as between the flange engaging surface and the spring engaging pin.
Claims14
In a sewing machine bobbin case (10) having means (11) to rotatably support a bobbin (5) with flanges (6, 7) thereon,
- means to control bobbin rotation and bobbin thread tension comprising
- a roller (20) having its terminal end portions (21) in engagement with the edges of the flanges (6, 7) of the bobbin (1), said roller having a diameter at the engagement surface which is small with respect to the diameter of the bobbin flanges;
- and yielding means (15, 17) yieldingly engaging the roller (20) and retaining the roller in position on the case and in yielding, frictional, rotational, engagement with the flanges (6, 7) of the bobbin, the yielding means applying a yielding drag on the roller which is transferred to the bobbin by engagement between the roller and the flanges of the bobbin.
In a sewing machine bobbin case (10) having means to rotatably retain a bobbin (5) having flanges (6, 7) in the case (10),
- means to control bobbin rotation and bobbin thread tension comprising
- a roller engaging the flanges (6, 7) of the bobbin (5) at a diametrical engagement point remote from the axis of rotation of the bobbin to be in rotation-transmitting engagement therewith, said roller having a radius of rotation which is small with respect to the distance of the engagement point of the roller on the flanges of the bobbin from the axis of rotation of the bobbin;
- and a spring means (15) engaging the roller and retaining said roller in said rotation-transmitting engagement with the bobbin (5) the spring means applying a yielding drag on the roller which is transferred to the bobbin by engagement between the flanges of the roller and the bobbin.
Dependencies are inferred from the claim text.