主权项 |
1. An apparatus comprising: a welding motor with a motor shaft, an eccentric shaft, a motor bushing, the motor bushing being fixedly attached to the motor shaft of the welding motor; an eccentric bushing; the eccentric bushing engaging the motor bushing, such that rotating the motor bushing rotates the eccentric bushing; the eccentric bushing being coupled with the motor bushing to transmit the torque; the eccentric bushing being pivotally mounted on the eccentric shaft so that eccentric axis of the eccentric shaft is coincident with rotation axis of the eccentric bushing; the eccentric shaft protruding into the eccentric bushing; the eccentric shaft being coupled to two stops that as a result of the coupling, rotate with the motor shaft; the eccentric shaft being coupled to a vertical link; the vertical link being linked to a gripper, which contacts an upper strap, when the upper strap is present; a first stop of the two stops engaging the eccentric shaft when the motor shaft rotates in the first direction; as a result of the first stop engaging in the eccentric shaft, when the motor shaft is rotated in the first direction, eccentric shaft is pushed into a configuration in which the rotation axes of the eccentric shaft is coincident with eccentric axis of the eccentric bushing creating an non-eccentric rotation of tile eccentric bushing when the motor shaft rotates in the first direction; the coupling of the eccentric shaft to the vertical link, the non-eccentric rotation of the eccentric shaft is translated, via. the coupling into a stationary neutral position of the gripper; a second stop of the two stops engaging the eccentric shaft when the motor shaft rotates in the second direction; when the second stop engages the eccentric shaft, the eccentric shaft is pushed into a configuration in which the rotating axis of the eccentric shaft is not coaxial with the eccentric axis of the eccentric bushing creating a maximum eccentricity in a rotation of the eccentric shaft when the motor shaft rotates in the second direction; as a result of the vertical link being linked to the eccentric shaft, the eccentricity in the rotation of the eccentric shaft is translated into art oscillatory motion of the vertical link; as a result of the vertical link being linked to the gripper, the oscillatory motion of the vertical link causes the gripper to move back and forth moving a piece of plastic back and forth to create friction if the piece of plastic is present. |