Abstract: An expansion shell assembly for mine roof bolts includes an expansion member threaded onto an associated mine roof bolt. A support device is annularly disposed around the associated roof bolt. An expansion shell is annularly disposed around the associated roof bolt between the expansion member and the support device. The expansion shell has a base ring for engaging the support device and fingers for engaging a peripheral edge of the tapered plug. The engagement between the base ring and the support device permits axial traverse movement of the support device relative to the expansion shell for tensioning the roof bolt.

Abstract: An expansion shell assembly for mine roof bolts includes an expansion member threaded onto an associated mine roof bolt. A support device is annularly disposed around the associated roof bolt. An expansion shell is annularly disposed around the associated roof bolt between the expansion member and the support device. The expansion shell has a base ring for engaging the support device and fingers for engaging a peripheral edge of the tapered plug. The engagement between the base ring and the support device permits axial traverse movement of the support device relative to the expansion shell for tensioning the roof bolt.

Abstract: A pressure sensor is provided in which the pressure sensing components are isolated from a portion of an attached buffer member which is connected to a fluid conduit. The offset characteristic of the pressure sensor isolates stress from being transmitted between an attached external fluid conduit and the sensitive components of the pressure sensor. One embodiment of the pressure sensor solders a fluid conduit structure to a buffer member that is attached to a pressure sensor die. An alternative embodiment of the present invention avoids the need for making solder connections between the sensor structure and external components by utilizing elastomeric conductors and pressure seals in association with the pressure sensor composite structure and first and second housing structures. These elastomeric conductors also provide improved stress isolation. The housing structures are used to compress to the seal and the elastomeric conductor against selected portions of the composite sensor.

Abstract: A flowthrough pressure sensor is provided which avoids the creation of crevices and creases that could provide difficult to cleanse regions. The pressure sensor is particularly adapted for use in applications that require cleansing to avoid the build up of bacterial-laden material. The flowthrough pressure sensor is particularly adapted for use in the measurement of bodily fluids. A first conduit is connected in fluid communication with the second conduit which, in turn, is associated with a pressure sensitive element and two compressible seals. A housing member is provided with an opening into which the compressible seals in the pressure sensitive element are disposed. A latching mechanism is provided to force the housing against a boss portion of the first conduit so that the seals and the pressure sensitive element are compressed therebetween.

Abstract: A hand held laser apparatus containing a semiconductor laser diode switchably connected to a power supply. The output of the laser diode is focused and collimated by a pair of lens. Circuitry is provided to allow for either continuous wave or pulsed modes of operation as well as the capability of varying the pulsewidth of the laser. A guide laser or a light emitting diode is provided to guide the operator. The power level of the guide laser is limited so that it transfers minimal power to the workpiece but provides a visible line of laser light along which the output of the semiconductor laser diode will travel. A photodetector may be positioned between the laser diode and the lenses. Additionally, the amount of current delivered to the laser in continuous wave mode of operation or the pulse width and duty cycle of a pulse may be measured and displayed.

Abstract: A laser diode apparatus for initiating explosives or other pyrotechnic devices that has capability of checking both the laser diode operation and the optical fiber continuity between the laser diode source and the explosives required to be detonated. Power isolation circuits are provided to control the flow of current to the laser diode, also isolation filters are used to allow only the command signals to initiate the firing circuits employed.