Sewing machine thread take-up lever

In a sewing machine having a thread take-up lever mounted for swinging movement about a fixed pivot, the lever having hook means at one end for receiving a thread, a shaft for driving a needle bar, and a cam disk mounted for rotation with said shaft, said cam disk having a face normal to said shaft with a cam groove therein, said take-up lever having a cam follower engage in said groove to impart a swinging motion to said take-up lever, said groove having side walls and a bottom wall;

• the improvement wherein said side walls are sloped with respect to said shaft whereby said groove has a trapezoidal cross section with the short side thereof along said bottom wall, said cam follower being tapered to fit in said groove to engage the side walls of said groove without contacting said bottom wall and being mounted to said take-up lever between said fixed pivot and said hook means, and further comprising spring means mounted to urge said cam follower into said grooves.