Label printer applicator with tamp pad back-pressure return

A drive and control system for a tamp pad for a label applicator of the type for separating labels from a continuous carrier strip and applying the labels to an object positioned at the applicator, the applicator having a supply roll and a rewind roll, the supply and rewind rolls being driven for moving the strip therethrough, the applicator including a tamp pad configured for receiving the label at a retracted position and contacting the label to the object to apply the label to the object when the tamp pad is at an extended position, the drive and control system comprising:

• a tamp pad cylinder having a compressed gas inlet for extending the cylinder and a compressed gas inlet for retracting the cylinder, the tamp pad being operably connected to the tamp pad cylinder;
• a pressure transducer in communication with the compressed gas inlet for extending the cylinder for measuring a pressure in the cylinder;
• compressed gas supply valves for supplying compressed gas to the compressed gas inlets, the pressure transducer being positioned intermediate one of the compressed gas supply valves and the compressed gas inlet for extending the cylinder;
• and
• a controller configured for controlling the compressed gas supply valves for moving the cylinder between an extended position and a retracted position, wherein the controller is responsive to one or more signals generated by the pressure transducer responsive to the pressure measured in the cylinder, movement of the cylinder from the retracted position to the extended position and back to the retracted position defining a cycle;
• wherein the controller generates a signal in response to a second increase in pressure measured by the pressure transducer, the signal corresponding to the extended position and terminating compressed gas flow to the inlet for extending the cylinder and commencing compressed gas flow to the inlet for retracting the cylinder for moving the cylinder to the retracted position;
• and wherein the controller recalibrates during the cycle and wherein a subsequent cycle is independent of pressure transducer measurements from the cycle, such that the tamp pad contacts the object to transfer the label to the object at a contact force that is consistent and about equal to a contact force of the tamp pad contacting previous and or subsequent objects to transfer labels to previous and or subsequent objects.