Abstract: Dump truck bodies are mounted to truck frames by a hinge so the truck body can pivot about the hinge to eject a load from the truck body. Loads carried by these vehicles can be extreme and the cyclical stress can generate cracks in the hinges. An upper pivoting connection of a dump truck hinge has side members each with a mounting portion that join to the sides of rails of the body and a lower pivot portion. The upper hinge structure is pinned to a lower hinge portion on the truck chassis at the pivot portion. Bracing between the sides add strength to the pivoting connection.

Abstract: A vial transport apparatus which is capable of storing and retrieving samples and then transporting them from one location in a sampling system to another without the complexity and expense of robotic arms or gripper elements is provided. A passive hook arrangement is utilized to engage the vials for transport and can be operated using a standard three motor system for transport in the X, Y, and Z directions. The hook supports the vial from beneath and at least partially surrounds the vial to entrap it during transport thereof.

Abstract: A degassing system is provided and includes a module for conditioning a liquid to be analyzed. The module includes a container holding a liquid, a degassing chamber, and a holder for the liquid container mounted on top of the degassing chamber. The holder provides stability to the module and contains any liquid spills. In another embodiment, the system includes an autosampler in conjunction with a degassing unit which includes a degassing chamber, a vacuum pump, and tubing for conducting liquid through the degassing chamber, which tubing is permeable to gases in the liquid.

Abstract: An apparatus for effective vacuum degassing of a liquid is provided for liquid chromatography applications. The liquid to be degassed is heated in the vacuum chamber by a radiator of electromagnetic energy, in one embodiment, or is heated before it enters the vacuum chamber. The liquid may also be agitated while in the vacuum chamber. In a preferred form, the vacuum degassing unit includes a vacuum chamber including a vacuum pump for creating a vacuum therein, a source of liquid, and gas permeable tubing for conducting the liquid through said vacuum chamber. The tubing includes first and second larger diameter blocks having at least one hole therein interconnected by at least one length of small diameter tube to form a leak-tight seal therewith.

Abstract: A syringe of relatively simple construction which is capable of both accurate and reproducible sample volume withdrawals, including volumes of 1.0 .mu.l or less, is provided. The syringe drive mechanism is preferably adapted for use in a liquid sampling apparatus and includes a threaded lead screw, a drive for rotating the screw, and a syringe having a plunger for withdrawing a liquid sample. The plunger is mechanically connected to the rotating lead screw by a nut threaded onto the screw and a slider mechanism associated with the nut which also is secured to the plunger. The nut is designed so that lateral misalignment of the drive screw does not affect the precise linear movement of the slider mechanism, and consequently, the plunger. This provides a mechanism which is less expensive to assemble and align properly, but which has a high degree of accuracy and reproducibility.

Abstract: Methods and apparatus for effective vacuum degassing of a liquid are provided for liquid chromatography. The bottles with the liquid are mounted above the vacuum degassing unit to provide a head pressure to the LC pump and physical stability to the bottles. The liquid is heated in the vacuum chamber by a radiator of electromagnetic energy (in one embodiment, infra-red light). Alternatively the liquid is heated before it enters the vacuum chamber. The liquid is in an agitated state in the vacuum chamber. In one variation, the liquid is conducted through the vacuum chamber through tubes wound around bobbins so as to expose a greater portion of the surface area of the tubes to vacuum. Circuitry stops the vacuum pump for a duration of a chromatographic run. The circuitry controls the LC pump and the vacuum pump so as to optimize the chromatographic conditions in the liquid chromatography analytical system.

Abstract: A sampler for taking samples from multiple sources has a fixed, non-moving needle at a sampling station. A sample vial is lifted from a tray at the sampling station. The needle pierces the septum of the vial and enters the sample as the vial is lifted toward the needle.The sample vial is also rotated as it is lifted, and a bar code reader makes a number of spaced apart, helical reads on a bar code label attached to the vial for label identification of the sample.The needle includes an inner, sample needle and an outer, gas-pressurization needle. The sample is withdrawn by the positive displacement of a syringe connected to the sample needle. The combination of the gas pressurization within the vial and the positive displacement of the syringe insures movement of the sample and accurate control of the volume removed independent of the viscosity of the sample.

Abstract: A multiple piston assembly pump of the kind which provides an overlap between the flow output of the piston assemblies during a portion of the strokes of the piston assemblies incorporates a method and apparatus for reducing pulsations in the flow during the time when the pump is changing over from one piston pumping to the other piston pumping. A first fast control loop responds to pump output pressure and is operatively associated with a second slow control loop which responds to average pump speed. A sudden pump speed change is detected, and the pump is run in a constant pressure mode until the speed returns to normal.

Abstract: A sampler for taking samples from multiple sources has a fixed, non-moving needle at a sampling station. A sample vial is lifted from a tray at the sampling station. The needle pierces the septum of the vial and enters the sample as the vial is lifted toward the needle. The sample vial is also rotated as it is lifted, and a bar code reader makes a number of spaced apart, helical reads on a bar code label attached to the vial for label identification of the sample. The needle includes an inner, sample needle and an outer, gas-pressurization needle. The sample is withdrawn by the positive displacement of a syringe connected to the sample needle. The combination of the gas pressurization within the vial and the positive displacement of the syringe insures movement of the sample and accurate control of the volume removed independent of the viscosity of the sample.