Abstract: A gripping mechanism includes an inclined surface, a rolling element, and a facing gripping part. The inclined surface is a surface inclined to a vertical direction. The rolling element freely rolls obliquely upward and downward on the inclined surface. The facing gripping part is arranged to face the inclined surface and forms an opening space with an end of the inclined surface, the opening space being narrower than a diameter of the rolling element. The rolling element includes: a core member forming a core of the rolling element; an annular member that is provided around the core member and has elasticity; and a plurality of ribs each of which is interposed between an outer periphery of the core member and an inner periphery of the annular member, and forms a gap between the core member and the annular member.

Abstract: A push-fit connector for joining a fluid line to a pipe. The pipe has a retaining rib, and the push-fit connector has an angled pipe section. One end section of the angled pipe section can be connected to the fluid line and the other end section can be fitted to the pipe in only one relative rotational position by using a pair of retaining arms which can engage with the retaining rib when the pipe and pipe section are fitted together. To join the pipe section and the pipe together in a torsion-resistant manner at different relative rotational positions, the pipe section is fitted in a locking manner to a coupling ring. The coupling ring has retaining arms to connect one coupling ring, together with the pipe section, to the pipe. The coupling ring and the pipe section are protected from relative rotation with respect to each other by teeth which can be mutually engaged at different rotational positions of the pipe section and coupling ring.