The basic component is a rotary gripper unit which is combined with, for example, a 3D handling system. The point of departure for finding the right solution involves the dimensions of the sample vial and the required torque. Whether or not different vials will need to be handled is also decisive.
The sample vials themselves dictate the technical requirements. It has to be determined how much torque is required to open and close them. The amount of required torque should always be tested in advance with the vials which will be used later on – under conditions which are as realistic as possible. If the sample vials are manually filled the thread may be contaminated with, for example, glucose or salt-containing media. After the vial has been closed, the liquid dries out and become sticky or crystallizes. Considerably higher forces are required for opening in this case. If testing is conducted exclusively with brand new vials, one runs the risk of not making the technical requirements strict enough.
Force can be reduced significantly at the gripper if a positive-locking connection is used. On the other, friction-locked gripping necessitates much higher forces.
Torques of up to 5 Nm and gripping forces (depending on arrangement) of up to 200 N can be implemented with standard solutions from Festo. Other torques are available upon request.
The necessary strokes can be determined on the basis of the height and diameter of the vials. In the case of vials of varying size, a larger gripper stroke is advantageous in addition to a longer Z stroke for the handling unit, in order to be able to fulfill all requirements with a single system if possible. This greatly reduces the complexity of the overall system.