Ball bearings

Claim 1

BALL BEARING FOR LONGITUDINAL MOVEMENTS, COMPRISING AT LEAST AN INNER TUBULAR ELEMENT AND AN OUTER TUBULAR ELEMENT ENGAGED CONCENTRICALLY WITHOUT SPACING THEREBETWEEN TO PROVIDE TOGETHER SEVERAL CLOSED-LOOP GUIDES, BALLS UNDER LOAD ONLY ON PART OF THEIR PATH OF CIRCULATION, THE PORTIONS OF THE GUIDES OF THE INNER TUBULAR ELEMENT EACH COMPRISING TWO STRAIGHT SECTIONS CONNECTED BY TWO SEMICIRCULAR ARCS, ONE PART OF THE GUIDES IN SAID INNER TUBULAR ELEMENT HAVING A WALL THICKNESS SLIGHTLY LESS THAN THE BALL DIAMETER AND COVERED OUTWARDLY BY SAID OUTER TUBULAR ELEMENT, SAID ONE PART OF THE GUIDES IN THE INNER TUBULAR ELEMENT HAVING ALONG ONE OF THE STRAIGHT SECTIONS AN INWARDLY OPEN SLOT, THE WIDTH THEREOF BEING INFERIOR TO THE BALL DIAMETER, THE OUTER TUBULAR ELEMENT PROVIDING THE BALL RACEWAY ALONG THIS SECTION, ALONG THE OTHER STRAIGHT SECTION AND THE TWO SEMICIRCULAR ARCS, THE OUTER TUBULAR ELEMENT HAVING THROUGH SLOTS FORMING THE OTHER PART OF SAID GUIDES, THE WIDTH THEREOF BEING INFERIOR TO THE BALL DIAMETER TO SECURE THEM AGAINST FALLING OUT AND SAID BALLS BEING CONTAINED IN THE STRAIGHT SECTIONS CONNECTED BY TWO SEMICIRCULAR ARCS, THE OUTER TUBULAR ELEMENT BEING RELATIVE TO THE INNER MEMBER THIN-WALLED AND IS MADE OF A PARTICULARLY PRESSURE-RESISTANT MATERIAL, AS SURFACEHARDENED SHEET STEEL, AND THE INNER TUBULAR ELEMENT BEING RELATIVE TO THE OUTER MEMBER THICK-WALLED, ONLY SLIGHTLY STRESSED AND MADE OF A READILY MOULDABLE MATERIAL.