The term 'Drive Assist' Pantograph Swivel Assembly relates to the incorporation of a link bar that joins between the levers applicable to both output shafts.

The longer of the two levers is driven by the connecting rod of the wiper linkage, which then drives the shorter lever. Under this arrangement the long lever relates directly to the main leg of the pantograph wiper arm and the short lever relates to the slave arm. In both cases the swivel assemblies incorporate the same bearing and shaft design standards. These provide the ability to maintain them in service by grease lubrication.

Main Drive
Swivel Assembly

Link Bar
Arm
Retaining Bolts
Drive Lever
The illustration above shows a typical 12 DIN main and 12 DIN slave output shaft configuration. Production designs also exist for other configurations such as 16 DIN main by 12 DIN slave and a 16 DIN main by 16 DIN slave output shaft.
In addition it will be noted from the illustration that the Matador design involves the use of a bolt for the purposes of securing the wiper arm and slave arm to the tapered spline of the two shafts. The reason for this is to assist the operator in maintaining availability of the vehicle in service in the event that the traditional threaded stud used by other suppliers had become sheared as a result of over-tightening the nut thus requiring replacement of the whole assembly. In the case of the Matador assembly it is merely a case of removing the shank of the sheared bolt and only fitting a new bolt.

Slave
Swivel
Assembly