We have a Vandercook 4 and the foot activated lever that opens the gripper stopped working. The lever is attached to the chain that then goes up through the cabinet and across under the bed to a push rod that pushes out the lever that works the grippers. The problem is in the connection between the chain and the push rod under the bed and I cant find any way to access this? There is a set of screws under the bed by the main ink cylinder but it would require me to take apart the print/trip mechanism and most of the shelving sheet metal to get the panel out. Is there some other way to access this? S/N 17864
OK, I looked at it more carefully and I think it is the taper pin. The center shaft the foot pedal is attached to is not turning with it. Thanks for all the help.
Paul, did I tell you about that No. 4 that fell over? It was the inner pin that sheared in that instance. And the fit of the lever onto the shaft was so tight that I ended up reaming the lever slightly so it could be reinstalled. It would not fit without a hydraulic press, not something at hand or on site.
Yes. Two pins, but in my experience it’s the outer one.
To activate the auto grippers loosen the bolt circled in the image below. Some No. 4s have an extra latch which holds the MS-127 Gripper trip latch back from from the MS-129 Cam.
Make that one of the two taper pins between pedal and chain; there is also a pinned lever connected to the chain, and either pin can shear when stressed. If following the linkages shows a failure under the bed, that does mean the bed must be lifted. There isn’t any easier access.
You could put the grippers into automatic mode.
See also this a photo of a No. 4 with the cabinet removed revealing the assembly from Nicholas Kennedy Trip/Print Press in Toronto.
Are you sure that the linkage has failed between the chain and the push rod? Have you checked that the taper pin on the pedal hasn’t sheared?
But if you are correct, here is the assembly drawing courtesy of Fritz Klinke/NA Graphics.