Connection systems used by industry in numerically controlled systems have generally relied on technology employing a projecting member concentric to a spindle axis shaped for secure connection with a matingly shaped bore. Locking mechanisms of the art such as radially directed wedge members have been actuatable by a number of methods including the use of threaded members having oppositely directed threads in engagement with bores of the wedge members. Radially oriented thru-bores are used in order to rotate the threaded member to radially displace the wedges. The threaded member may thereby be actuated by a manual or automatic tool member.
Displacing the wedge members from a location at the lateral sides of the tool head is sometimes disadvantageous. The clamping forces generated are limited by the threaded connection between the threaded member and the wedge members.
In addition, providing a cooling system such as by feeding cooling fluid through the threaded member to the tooling has not typically been possible.
In German publication entitled "tz fur Metallbearbeitun", 1984, No. 3/84, page 26 (system WIDIA), a general discussion of a connection system is presented. Clamping pins positioned in inclined bores engage recesses in a tool head when actuated in an outward radial direction. The tool head is drawn against the spindle when the clamping pins are actuated radially outward and released when drawn inward. Displacement of the pins is provided by a central actuating rod which engages the pins via a conical head portion. The clamping pins are moved radially inward by correspondingly shaped recesses of the tool head for tool changing. The use of clamping pins however both limits the clamping forces and necessitates the use of substantial forces to separate the tool head from the spindle when the pins become stuck due to chips or the like.
It is therefore an object of the present invention to provide a connection system for connecting an interchangeable tool head to a spindle of a numerically controlled machine by central actuating means capable of generating high clamping force and quick release.