Abstract: An adjustable volume pipette sampler and pressure-generating device comprises a barrel slidably and rotatably containing a cross-shaped plunger of radial flanges which is manually rotatable around its axis in the barrel, at least one of the radial flanges having open-ended slots or notches. A stop disc is rigidly secured on the top flange of the barrel in such a manner that it does not interfere with the vertical motion of the plunger shaft when its axial position is such that adjacent flanges of the plunger straddle the stop disc. Otherwise, the stop disc cooperates within the notches to stop vertical movement of the plunger at a selected position corresponding top a selected pipette volume.

Abstract: An adjustable volume sampler or syringe comprises a pair of barrels axially aligned and retained together by complementary screw threads. The volume is controlled by relative rotation of the barrels. Coupling mechanisms are provided at an outlet end of one of the barrels for attaching a second cylinder or other accessories.

Abstract: A precision micropipettor device, primarily useful for dispensing a predetermined, accurate fixed volume quantity of fluid, includes a tubular fluid holding barrel having a dispensing end and a working end, a removable fluid holding outlet conduit secured to the dispensing end, a plunger shaft assembly for reciprocal movement within the tubular fluid holding barrel to dispense reagent contained in the fluid holding outlet conduit, and a mechanism for predetermining the range of movements of the plunger shaft assembly along the longitudinal length of the fluid holding barrel. The device can repeatedly dispense an accurate predetermined quantity of fluid. The device includes visual indication elements for communicating to an operator the resting position of the plunger shaft assembly. The device also includes a spring for returning the plunger shaft assembly to a preferred resting position after each use which spring by itself may constitute the mechanism for predetermining the range of plunger movement.

Abstract: A liquid micro-dispensing pipet consisting of a main barrel with a snap-on dispensing tube tip. An axial, upwardly spring-biased operating shaft is slidably and rotatably engaged in the barrel, connected to a plunger in the dispensing tip. The snap-on tip can be at times disengaged from the barrel by exerting axial downward force on the shaft. Stop means to limit the intake movement of the plunger is provided, said stop means consisting of an abutment sleeve slidably and non-rotatably mounted on the upper portion of the shaft and threadedly engaged in the barrel, the abutment sleeve being engageable from below by a stop washer secured on the shaft, which is normally urged upwardly by its biasing spring. The normal elevated position of the plunger can be varied by rotating the barrel relative to the shaft.

Abstract: A magnifying indicator for a thermometer or similar columnar instrument, said indicator consisting of a one-piece body of transparent plastic formed with a cylindrical base block and an upstanding lens on the front portion of the base block. Opposite the lens the base block is formed with a rearwardly-facing vertical V-groove in which the columnar instrument is receivable. A U-shaped wire spring is anchored at one side of the groove and transversely overlies the groove. The spring is arranged to allow the columnar instrument to be slipped into the groove so as to engage against the flat sides thereof and thereafter to clamp the instrument in the groove to prevent angular disorientation of the lens relative to the columnar instrument, while permitting sliding adjustment of the magnifying indicator along the instrument scale.

Abstract: A liquid repetitive dispensing device consisting of a main body containing an elongated square ratchet bar slidably engaged with the main body, the ratchet bar having two adjacent longitudinal faces having ratchet teeth of different pitch. A push button is provided in the main body having an inclined bore containing a spring-biased pawl drivingly engageable with the ratchet teeth responsive to inward movement of the push button. An abutment bushing surrounds and conformably receives the ratchet bar and is adjustably rotatably received in the main body. The bushing is formed with inclined bottom cam surfaces extending toward the ratchet teeth and being engageable by the pawl. The degree of driving engagement of the pawl with the teeth is in accordance with the axially adjusted position of the bushing. A yieldable detent in the main body is selectively receivable in axially spaced recesses in the bushing to lock it in adjusted position relative to the main body.

Abstract: A liquid micro-dispenser consisting of a barrel with a snap-on dispensing tube tip at one end containing a dispensing plunger attached to an operating shaft extending through and having an abutment ring engageable with an adjustable stop bushing threadedly engageable within the other end of the barrel. The bushing has a locknut engageable with said other end of the barrel to lock the bushing adjustment, thus locking the adjusted intake volume of the dispensing tip. A square-flanged top bushing is secured to the upper end of the stop bushing, and a protective sleeve member is secured to the top bushing and surrounds the stop bushing and the upper portion of the barrel. The barrel has a volume scale visible through a volume-indicating window in the sleeve member. The sleeve member has a large cut-away aperture providing access to the locknut to allow it to be manually loosened for adjusting the volumetric setting, and for subsequently re-tightening the locknut.

Abstract: A graphics instrument is disclosed for use in drawing and measuring. The instrument includes a pair of coplanar scale members mounted for concentric mutual rotation. A circular graduated scale on the outer member displays angular degree and radian values, and this scale is in register with a circular graduated scale on the inner member which displays both angular and trigonometric function values. Straight edges are formed to extend along axes of each scale member to facilitate measurement and drawing by a marking instrument. In one embodiment the outer member defines a polygon configuration which provides a straight edge, and the straight edge of the inner member extends along a diameter of the latter. In another embodiment the two members are annular and carry radially extending arms which define straight edges upon which graduated linear measurement scales are marked. The inner member is formed with a central opening into which extensions of the two arms project.

Abstract: A burette consisting of a calibrated syringe chamber with a top flange and a reciprocable dispensing plunger. The plunger has a top actuator with a depending vertical rod on which is adjustably mounted a stop collar serving as a dispensing volume indicator and being engageable with said top flange to limit the upward extension of the plunger. The syringe chamber has a bottom outlet conduit including a check valve which opens when the plunger is drawn upwardly. The syringe chamber also has a discharge conduit at the level of the lowermost position of the bottom end of the plunger, the discharge conduit having a check valve which opens when the plunger is pushed downwardly for a discharge stroke. The chamber has a vent tube connected thereto at its lower portion. Below this the chamber has a peripheral rib, and O-rings are mounted on the chamber above and below the rib.