Multi-tiered pipette tip holder and ejection mechanism for a dynamic broad volumetric range pipette

A pipetting device with a multi-tiered pipette tip holder and ejection mechanism comprising:

• an elongated pipette body comprising an air inlet at a dispensing end;
• an ejector element;
• a concentric cylinder assembly comprising:
• a chamber cylinder in fluid communication with the dispensing end, a small tip ejection cylinder having a small tip ejection edge and a large tip holder portion, and
• a cylindrical dispenser housing having a large tip ejection edge, wherein:
• the chamber cylinder is concentrically received within at least a portion of the small tip ejection cylinder;
• the small tip ejection cylinder is concentrically received within at least a portion of the cylindrical dispenser housing and configured to move up and down in relation to the chamber cylinder;
• the cylindrical dispenser housing is configured to move up and down in relation to the small tip ejection cylinder;
• an ejection rod in mechanical communication with the ejector element and configured to:
• cause the cylindrical dispenser housing to move to a first position wherein the large tip ejection edge contacts and ejects a large pipette tip from the large tip holder portion when a first force is applied to the ejector element;
• or
• cause the small tip ejection cylinder to move to a second position wherein the small tip ejection edge contacts and ejects a small pipette tip from a small tip holder portion of the elongated pipette when a second force is applied to the ejector element;
• and
• a locking mechanism comprising:
• a trigger,
• a biasing element, and
• a locking rod movable between a locking position and an unlocking position,
• wherein movement of the cylindrical dispenser housing and the small tip ejection cylinder to the second position causes the locking rod to move to the locking position and prevent upwards movement of the small tip ejection cylinder.

A pipette with a multi-tiered pipette tip holder and ejection mechanism comprising:

• a pipette body comprising an upper drive unit section and a lower dispensing section, the lower dispensing section comprising a small tip holder portion and a chamber cylinder and having a fluid inlet to enable fluid to be drawn into the chamber cylinder or discharged therefrom;
• and
• an ejection assembly comprising:
• an ejector element,
• ejection rod,
• a first dispensing cylinder having a large tip holder portion and a small tip ejection edge,
• a second dispensing cylinder having a large tip ejection edge,
• wherein the first dispensing cylinder is concentric with at least a portion of the chamber cylinder and configured to move up and down in relation to the chamber cylinder, and
• wherein the second dispensing cylinder is concentric with at least a portion of the first dispensing cylinder and configured to move up and down in relation to the first dispensing cylinder;
• wherein the ejection rod is configured to:
• (i) contact the second dispensing cylinder and move the second dispensing cylinder to a first position wherein the large tip ejection edge contacts and ejects a large pipette tip from the large tip holder portion when a first force is applied to the ejector element;
• or
• cause the first dispensing cylinder to move to a second position wherein the small tip ejection edge contacts and ejects a small pipette tip from the small tip holder portion when a second force is applied to the ejector element;
• and
• a locking mechanism comprising:
• a trigger,
• a biasing element, and
• a locking rod movable between a locking position and an unlocking position, wherein movement of the second dispensing cylinder and the first dispensing cylinder to the second position causes the locking rod to move to the locking position and prevent upwards movement of the first dispensing cylinder.