×

Repetition pipette

  • US 5,573,729 A
  • Filed: 04/20/1995
  • Issued: 11/12/1996
  • Est. Priority Date: 04/27/1994
  • Status: Expired due to Term
First Claim
Patent Images

1. A repetition pipette including a syringe receiving section (5) for a mounting portion of a syringe (6), a receiving member (9) having a piston receiving portion for the mounting portion of a syringe piston, piston returning means (10) for moving said receiving member away from said syringe receiving section, piston advancing means (13, 17, 22) for advancing said receiving member towards said piston receiving portion, the piston advancing means comprising a rack having a toothing (13) connected to said receiving member, and an actuating element (17) movable along an actuation path (B), and a pawl (22) pivotally mounted thereto, said pawl being movable into engagement with the toothing (14) of the rack so as to drive the rack for an advancing step when the actuating element is advanced, and is moved out of engagement with the rack when the actuating element is returned, means (23,27) for adjusting a step width of the advancing step, the step width adjusting means comprising a sleeve-shaped withholding element (23) displaceable along the rack by an adjusting element (27) for preventing the pawl from engaging the rack, and stroke length limiting means (29,29'"'"') controlled by the step width adjusting means (23,27) so as to increase a stroke length (B) of the actuating element (17) when the step width increases and to decrease the stroke length of the actuating element when the step width decreases;

  • wherein said stroke length limiting means includes an abutment (29,29'"'"') limiting the stroke length (B) of the actuating element (17) at the beginning of the stroke length, said abutment being adjustable by the step width adjusting means (23,27) both in an advancing and a returning direction (V and R) of the actuating element;

    wherein the withholding element (23) comprises a lateral shoulder (29,29'"'"') forming said abutment; and

    wherein said actuating element (17) includes a pair of parallel legs, (18,18'"'"') with one leg extending transversely across one side of said rack (13), and the withholding element (23) has said shoulder (29) on said one side of the rack (13).

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×