a friction fitting manner immediately after the pivoting of the locking lever 35 the bobbin case 3 is axially ejected out of the hook 1 by the tension force of the coil spring 23 because the second end of the spring 23 contacts a stop 55 in the bobbin case 3 cf fig5 the bobbin case 3 can now manually be removed from the hook 1 here the bobbin 5 is held in a friction fitting fashion by the back of the latching leg 45 of the locking lever 35 as soon as the force f upon the locking lever 35 reduces i e when the operating person grasps the bobbin case peripherally with two fingers locking lever 35 rotates in the clockwise direction and holds the bobbin 5 via the back of the braking leg 47 cf fig6 it is discernible from fig7 that the latching leg 45 is pivoted in the clockwise direction to the very right by the force of the torsion spring 37 and contacts a cam shaped end 59 embodied on the primary leg 43 at a stop 61 in the opening 29 a refilled lower thread bobbin 5 is inserted from above into the bobbin case 3 here it glides against a certain resistance over the angled surface 57 of the braking leg 47 of the locking lever 35 downwards and is here held in position by the back of the brake leg 47 thus when inserting the bobbin case 3 into the hook 1 this way the bobbin 5 is held and cannot fall out even when the bobbin case 3 is tilted slightly downwards as soon as the hook shaped end 51 of the latching leg 45 contacts the sleeve 9 the locking lever 35 is slightly pivoted in.