Turn-ta′ble.
1. (
Railroad-engineering.) A platform which rotates in a horizontal plane, and is used for shifting rolling stock from one line of rails to another.
Devices common to all are the plat-
[
2663]
form, which has one or more tracks of rails on its upper surface; rollers on which it turns, gearing for rotating it, a central pivot on which it rotates, a circular track on which the rollers move, and solid foundations for this track and for the central pivot.
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Turn-table, with wooden frame. |
Kelly's turn-table (
Fig. 6809) is centrally supported on a series of frusto-conical rollers turning on arms radially projecting from a collar, which revolves around the axis of the table.
The apexes of the cones would, if they were complete, meet at a point in their axis.
They are interposed between two annular castings correspondingly beveled, the lower of which is fixed, and serves as a track, and the upper is attached to and turns with the table.
Flanges on the inner ends of the rollers prevent their being pushed outwardly by the pressure.
In a modified arrangement small conical rollers turning between the large rollers and plates on the ends of the arms which carry them are substituted for the flanges.
See also
Figs. 6810,
6811.
Adams's turn-table (
English) floats in a water-tank.
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Turn-table. |
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Turn-table. |
2. A device upon which a microscope slide is held for tracing the circular cement cells in which objects are placed for examination.
