Abstract: An optical system is disclosed for a densitometer which scans an electrophoretically separated sample and provides an output signal for graphical display indicative of the optical density of the scanned sample. The optical system provides storage for a plurality of filter assemblies selectively used depending on the mode of densitometry scanning. It includes a turret assembly, a detector housing, and a lamp support to permit an operator convenient selection capability of a desired filter when scanning in either visible or fluorescent modes of operation. A plurality of optical density and blocking filters are sandwiched between turret plates at spaced radial positions. The plates have aligned openings adjacent to the filter areas to permit light to pass through the filters for detection.

Abstract: An improved paper tensioning device, for use with a chart recorder or densitometer of the type where the paper is tightly wound around a hollow core, which paper tensioning device prevents the chart paper from unwinding too fast. The paper tensioning device comprises a rod and plug combination with the plug secured to one end of the hollow core and with the rod being inserted through the hollow core, from the other end thereof, to mate with the plug. Axial pressure on the rod is maintained to cause a constant drag on the hollow core and on the chart paper. The plug and hollow core may be an integrally formed unit onto which the paper is wound. Optionally, the rod and plug may be a one piece unit or the rod, plug and core may be a one piece unit.

Abstract: In a chart recorder where a print head is used to record data on a moving strip of chart paper, an improved apparatus for biasing the print head against the moving chart paper. The biasing apparatus provided includes a cantilevered leaf spring to maintain a constant and preset pressure between the print head and the moving chart paper. The distal or fixed end of the leaf spring is anchored to the frame of the chart recorder and the print head is mounted on the free end of the cantilevered leaf spring so that the leaf spring maintains a constant pressure between the print head and the moving chart paper. The cantilevered spring is adjustable to provide the desired amount of pressure between the print head and the moving chart paper. When a new roll of chart paper is inserted into the chart recorder, the cantilever spring re-establishes and maintains the pressure between the print head and the new roll of chart paper.

Abstract: This application discloses an antenatal cell extracting device comprising a thin, flexible, plastic tube adapted for cervical insertion in a human female. A flexible closure is provided at the proximal end of the plastic tube, and passing through the flexible closure, the plastic tube and the distal end of the tube is a plunger. A valve in the form of a smooth ball, the diameter of which is greater than the diameter of the tube, is fixed to the end of the plunger, and, upon reciprocating movement of the plunger with reference to the tube, the valve is caused to open and close. Means are provided for causing fluid to flow through the tube when the valve is opened, such means, preferably taking the form of a syringe connection to the flexible closure.

Abstract: A timed pulsed fuel injection device which meters fuel continuously and distributes flow pulses to n nozzles through a rotary distributor pressure cascading device which totally isolates the metering event from variations and dynamic effects in the n injection lines.