Abstract: A drive mechanism for reciprocating a sewing machine needle bar endwise from an actuating crank is disclosed in which the lateral stud on the needle bar to which the drive link is connected is fitted with a ball bearing slidably constrained in a guide slot formed parallel to the path of needle reciprocation in a stationary guide frame. The forces and reactions occasioned by alternate acceleration and decelleration during each needle bar stroke will cause the outer race of the ball bearing to engage first one side then the opposite side of the guide slot during each stroke thus turning the bearing in opposite directions and distributing the wear.

Abstract: This disclosure relates to needle guards for rotary loop takers in sewing machines and has its purpose prevention of interference between the needle and the loop seizing beak of the rotary loop taker during the sewing operation. A needle guard is provided which takes the form of a rib member formed in the bottom wall of the rotary loop taker which rib member is spaced from the vertical side wall of the cup-shaped rotary loop taker. The rib member is relatively thin and may be said to be resilient. Means are provided for biasing the rib member toward and away from the vertical side wall of the rotary loop taker in order that the rib member may be adjusted relative to the reciprocating path of the needle so that the needle will be deflected away from the loop seizing beak of the rotary loop taker upon penetration of the fabric by said needle and thereby prevent a scoring of the loop seizing beak or a breakage of the needle.