Abstract: An adjustable pipette includes a body containing a plunger assembly including a thumb button that is axially moved in alternating relatively shorter sample aspirating and relatively longer dispensing strokes. Guide slots in a guide sleeve receive a stop pin carried by a plunger shaft, and the slots define two axially and circumferentially spaced lower stops for aspirating and dispensing strokes respectively. The thumb button includes offset lobes that apply a rotational torque to the plunger shaft when pressed by the user. The user presses one lobe for an aspirating stroke to rotate the plunger shaft in one direction and align the stop pin with uppermost lower stops for a relatively short aspirating stroke and the user presses the other lobe for a dispensing stroke to rotate the plunger shaft in the other direction and align the stop pin with lowermost lower stops for a relatively long dispensing stroke.

Abstract: A pipette for transferring liquid samples includes a body having a handle and a base. A piston assembly is axially movable in the body. A movable lower stop is placed in the path of the piston assembly to stop the piston to limit the length of an intake stroke and is withdrawn from the path to permit axial overtravel during a discharge stroke. The lower stop is positively controlled by a manually operated mechanism including a stop control push button at the top of the handle in front of a piston push button. A mechanism for ejecting a tip from the base includes a lever at the top of the handle providing a mechanical advantage when pressed at either end. In an alternate embodiment, a dual spring overtravel arrangement is used, with the piston return spring telescoped within the overtravel spring.

Abstract: A generally flat flashlight is concealed in an article of clothing or other accessory used by a person to illuminate an area adjacent an opening in the article of clothing or other accessory. In the case of a necktie that is to be worn around the neck of a person, the necktie is made of fabric or textile material and is formed into an elongated flattened tubular configuration with front and rear plies so that an inner area is formed between the plies. Adjacent a distal end portion of the necktie, a pocket or holding area is formed within the inner area of the necktie with an opening formed at the distal end thereof. The relatively flat, flashlight that is battery operated is adapted to be disposed within the pocket with the light emitting portion of the flashlight directed to the opening so that when the flashlight is actuated, light emitted from the flashlight will illuminate the area beyond the end of the necktie.

Abstract: An adjustable pipette has a piston axially moveable in a body for alternately drawing and dispensing a liquid sample. An upper stop is moved axially to vary the sample size by rotation of a threaded shaft. A drive member is keyed to the threaded shaft for simultaneous rotation but the drive member and shaft can freely move axially relative to one another. The drive member is moved axially to an unlocked position in order to adjust the sample volume and is axially moved to a locked position in which rotation and inadvertent misadjustment of the sample volume is prevented. A collar on the drive member fits tightly into a throat of the pipette body to lock the drive member against rotation.

Abstract: A continuously adjustable liquid mixing device for intermixing selectively adjustable volumes of several liquids comprises a body for holding a plurality of volumes of the liquids including a recess at an upper end. A mechanism is provided for drawing up the volumes of liquid into the body and thereafter expelling the same from a lower end. A volume adjusting selecting mechanism is provided for at least one of the volumes including a rotary element mounted in the recess and frictionally engaging a wall surface thereof for retaining a selected volume that is desired. A rotary drive system is provided for rotating the volume adjustment mechanism and is readily accessible externally of the body for convenient manipulation to select a desired volume. The drive system is movable between an outer operating position for easy manipulation and a retracted position when not in use.

Abstract: A battery powered flashlight includes a case holding a battery, lamp, reflector and an electric circuit including switch means for connecting and disconnecting the battery to selectively energize and turn off the lamp. The flashlight includes a lens supported adjacent an end or side of the case in front of the lamp and reflector forming a rectangular beam of light when the lamp is energized for providing a non-glare illumination of a relatively small rectangular area such as along a sidewalk or a stair tread. The flashlight may also include a second lamp and reflector at an opposite end of the case providing a spotlight and a switch for selecting between the spotlight and the area illuminating beam. The flashlight may include a carrying handle in the form of a bail which acts to operate the switch for initiating the rectangular beam of light or alternatively the spotlight.

Abstract: A low distortion audio amplifier utilizes a pair of field effect transistors connected in a balanced source follower configuration. A tapped inductor connected between the sources of the field effect transistors provides inductive coupling between the sources and maintains the sources at the same direct current potential. This permits the voice coil of a loud speaker to be connected directly across the sources without causing excessive direct current to flow through the voice coil.

Abstract: A fraction collector wherein a head is aligned in sequence with individual containers of an array of containers so that fractions or samples may be deposited into the containers from a delivery tube supported by the head. A table surface slidingly supports a number of racks holding rows of containers. The racks are releasably attached to spaced points along a chain moved by a chain drive motor around a closed loop above the table surface. The head is supported above the path of the racks and is moved across the racks and along the rows by a head drive motor. A control circuit controls the chain and head drive motors to advance the chain in increments to position successive rows beneath the head, and moves the head in increments along the container rows to position the head above individual containers.