Abstract: A retrofit system for a multi-spindle machine which includes a brake clutch (72), a feed clutch (70), and a high speed clutch (68) which are incorporated into the drive train gear layout of the multi-spindle machine. All three clutches are controlled by an electrical control circuit which includes a timer (80). When the multi-spindle machine shifts from high speed to low speed the control system activates the brake clutch for a short time period set in the timer, which causes the drive train gears to quickly slow down, allowing synchronous meshing with the low speed drive train of the multi-spindle machine and enabling a reduction in machine cycle time.

Abstract: A threading clutch apparatus (10) for a multiple spindle machine which allows for selective engagement of connected gears with a rotating shaft (12) which is connected to the threading clutch apparatus. The threading clutch apparatus includes a hub (14) which is positively connected with and rotates with the shaft (12), and a housing (18) which is supported from the hub via bearings (28 and 30). The threading clutch apparatus further includes a pair of pistons (48 and 66) which are positioned to communicate with a compressed fluid source. The threading clutch apparatus further includes a first and second plurality of friction disks (92 and 122) which are operably connected with the gears of the multiple spindle machine. When compressed fluid is communicated to a piston, the piston compresses the associated plurality of the friction disks which results in the positive engagement of the associated gear and rotation of the gear with the shaft.