Abstract: Strong, light weight master cylinders for hydraulic braking systems are produced by incasing a section of steel tubing within a diecasting of metal such as an alloy of magnesium or aluminum. Master cylinders can thus be produced by diecasting the metal in situ around a seamless tube having a smooth accurately oversized bore so that it incases the exterior surface and extends over one end thereof and through predetermined shrinkage produces a final uniform bore diameter and operating surface. Tooling requirements are minimal, with little if any machining being needed following the diecasting operation. Unit production cost is thus lower than that of castings made with permanent molds. Light weight diecastable metals can thus be used in combination with strong but relatively thin steel tubing to provide durable master cylinders that are lighter, simpler and less expensive to make than cast iron cylinders. This composite construction can be used in power cylinders for numerous light weight applications.

Abstract: Strong, light weight master cylinders for hydraulic braking systems are produced by incasing a section of steel tubing within a diecasting of metal such as an alloy of magnesium or aluminum. Master cylinders can thus be produced by diecasting the metal in situ around the tube so that it incases the exterior surface and extends over one end thereof. Tooling requirements are minimal, with little if any machine being needed following the diecasting operation. Unit production cost is thus lower than that of castings made with permanent molds. Light weight diecastable metals can thus be used in combination with strong but relatively thin steel tubing to provide durable master cylinders that are lighter, simpler and less expensive to make than cast iron cylinders.