38 the cover 34 is secured against the arm 14 in a substantially upright or closed position by a latch member 40 which engages an aperture 42 formed in the cover 34 and which may be operated by depressing a cover release button 44 preferably carried on the arm 14 the arm 14 contains a chamber 46 into which the cover 34 may be rotatably pivoted and which contains a plurality of thread handling instrumentalities which influence the control of the thread as it is removed from the thread supply the cover 34 has a window 47 through which the quantity of thread remaining in the cassette 32 may be observed fig2 shows that the thread cassette 32 contains a thread supply 48 which is preferably formed in a coil shape with the thread end supplied to the needle 20 being removed from the center of the coil to provide for a large volume of thread without creating an excessive load which would be created if the whole thread mass was rotated as a conventional thread spool or bobbin the cassette 32 is preferably formed from an easily molded material as for example plastic preferably the cassette 32 is formed with a body 50 and a top 52 which permits the cassette 32 to be easily filled with thread before enclosing the body 50 with the top 52 the top 52 has formed thereon a window 54 through which the color and quantity of thread remaining in the cassette 32 may be observed and a similar window 56 is formed on the bottom to permit observation of.