| 摘要 |
In one embodiment, a touch input device has a flame and explosion resistant enclosure supporting a display device which is observable from outsidethe enclosure. The touch screen input device comprises a frame attachable to an axial end of the housing. A transparent window is receivable in the frame for securement to the housing to form an end of the enclosure and defining a view port for viewing the display device. An interface between the window and the frame defines a flame suppressing path extending continuously about the periphery of the interface. A light emitting device is located within the enclosure for directing a beam of light through the window. A first reflector islocated on a side of the window opposite the light emitting device for reflecting the beam of light across the view port. A second reflector is located on the same side of the window as the first reflector and spaced from the first reflector to reflect the beam of light from the first reflector through the window and into the enclosure. A light receiving device is located within the enclosure on the same side of the window as the light emitting device. The light receiving device for detecting the presence of the beam of light or the absence of the beam of light. In another embodiment, an apparatus for transmitting a signal through a barrier of a sealed enclosure is disclosed. The apparatus comprises a body having a length greater than the thickness of the barrier and an opening extending therethrough. Attachment structure fixes the body in an opening extending through the barrier. A light transmissive member is fit in the opening of the body to inhibit flame propagation between the body and the light transmissive member. Retention structure retains the light transmissive member in the opening in the body and connects a pair of fiber optic members to ends of the body in light transmitting communication with the light transmissive member.
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