Control system and method for automatic fastening machines

Apparatus for riveting two or more side-by-side workpieces together, the workpieces being provided with aligned apertures in which a slug rivet has been received, said apparatus comprising:

• a) first and second riveting ram means aligned with the rivet, the first riveting ram means being disposed facing said one side of said one workpiece, and the second riveting ram means being disposed facing the outer side of another workpiece;
• b) first moving means capable of moving the first riveting ram means toward the workpiece;
• c) second moving means capable of moving the second riveting ram means toward the workpiece;
• d) first and second servo control devices in controlling relation to said first and second moving means;
• and
• e) a multi-axis motion controller connected in controlling relation to said first and second servo control devices for controlling movements of said first and second riveting ram means to upset said rivet in said workpieces.

In an automatic apparatus for installing fasteners in a workpiece including a plurality of tools for performing fastener installation operations on said workpiece and a control system for controlling operation of said tools and wherein at least one of said tools includes a rotary operating component, an encoder for said at least one tool comprising:

• a) a generally disc-shaped element mounted on said tool for rotation therewith and having a circumferential surface provided with successive regions of alternating optical characteristics;
• and
• b) a pair of optical devices connected to said control system and in operative relationship with said regions and positioned relative to said regions and to each other;
• c) so that information from said devices can be utilized by said control system to determine the speed and direction of rotation of said tool.

A method for riveting two or more side-by-side workpieces together, the workpieces being provided with aligned apertures in which a slug rivet has been received, said method comprising:

• a) providing first and second riveting ram means aligned with the rivet, the first riveting ram means being disposed facing said one side of said one workpiece, and the second riveting means being disposed facing the outer side of another workpiece;
• b) providing second moving means capable of moving the first riveting ram means toward the workpiece;
• c) providing moving means capable of moving the second riveting ram means toward the workpiece;
• d) providing first and second servo control devices in controlling relation to said first and second moving means;
• and
• e) utilizing a multi-axis motion controller connected in controlling relation to said first and second servo control devices for controlling movements of said first and second riveting ram means to upset said rivet in said workpieces.

A method of riveting two or more side-by-side workpieces together, the workpieces being provided with aligned apertures in which a slug rivet has been received, said method comprising the following steps:

• providing first and second riveting ram means aligned with the slug rivet, the first riveting ram means being disposed facing said one side of said one workpiece and the second riveting ram being disposed facing the outer side of another workpiece;
• moving the first riveting ram means toward the workpiece in a programmed axis move under control of a multi-axis motion controller to establish a first desired die cavity;
• moving the second riveting ram means towards the first riveting ram means in a programmed axis move under control of said controller until both ends of the slug rivet are just in contact with both riveting ram means;
• and
• moving the first and second riveting ram means towards each other under control of said controller to form upset heads on both ends of the slug rivet.