Thermo static elememt to Thread gauge
Thermo-static element. An elemcnt
. or device which, when it receives Ihe degree of heat for which it is constructed to operate, will cause Ihe opening or closing of valves, switches, or other parts. A common form is a coil of hollow, metal tubing filled with ether or some other liquid and scaled at both ends. A less used form consists of a bimetal ann which, by contraction and expansion, operates a buttertly valve.
Thickness gauge. or feeler. (Mech.) It is shaped somewhat like a pocketknife. and has blades varying in thickness by thousandths of an inch. It is used in adjusting parts with a desired amount of clearance, as the valve of an automobile motor.
Thickness ratio. (Aero.) The ratio of the maximum thickness of an airfoil section to its chord.
Thick space. (Prillt.) Spaces cast three to an em of any. particular body.
Thimble. (Mech.) (I) A short tube, usually metal, to slip in, over,. or about something, as over a bolt, pin, etc. (2) A grooved ring set in the eye of a rope or cable to prevent chafing and deformation.
T hinge. (Bldg.) Consists of a strap with a "butt" at right angles to it. Used mainly for oUlside work on gates, doors, etc.
Thin space. (Print.) Spaces cast five to an em of their own body.
Third-angle projection. (Draft.) Projection of different views in mechanical drawing usually a plan or top view, a front view, is taken with reference to the near side of the view from which it is projected.
Third brush. (Auto.) An auxiliary brush which regulates the current output ofth.e generator by increasing or decreasing the field-coil current.
Third-class lever. (Mech.) A lever with the power applied between weight and fulcrum.
Thixotropic. (PEa!>'t.) Liquid plastics which contain suspended solids, such as finely divided silica, are gel-like at rest, but fluid when applied. A thixatropic resin remains more or less fixed on an inclined surface, inhibiting its flow downward.
Thixotropy. (Chern. PEas!.) The property by which some compositions become solid at rest but liquify again on agitation.
Thread. A fine cord or filament, usually of nonmetallic material, as silk, cotton. or wool. Also SEE SCREW THREAD.
Thread-cutting screws. (Mach.) The entering end of such screws contains a slot with serrated cutting edge which makes the use of a tap unnecessary. The screw cuts its
own threads. The use of threadcutting screws is indicated for sheet metals, softer alloys, plastics. etc.
Tbreaded sleeve. (Shopwk.) A shell of metal, usually cylindrical and threaded internally; used for connecting two pieces of pipe or rods.
Thread gauge. (Meta/wk.) A gauge for checking the pitch of screw threads.
Threading to three wire cut Three-wire circuit
Threading: The cutting of screw threads, either internal or ex1ernal.
Thread miller. (Mach.) A milling machine designed for thread and worm cutting.
Thread plug. (Plast.) A part of a mold that shapes an internal thread which must be unscrewed from the finished piece.
Thread-rolling. (Mach.) The formation of screw threads by hardened rolls or dies which roll grooves into a blank and raise enough metal above t"'e surface of the blank to form a thread; such threads are stronger and less expensive than cut threads.
Threads per inch. (Mach.) Refers to thread size. Standard practice fixes the number of threads per inch for any diameter: that is ~/2-in. diameter, 13 threads per inch: I-in. diameter, 8 threads per inch. etc. The purposes of theads are: (a) to hold parts together, i.e., screws, qolts, nuts etc.; (b) to tighten parts together to withstand the pressure of liquids or gases, Le., pipes, fittings, etc.; (c) to transmit power as
. through jack screws, worm drives, etc.: (d) to adjust with great accuracy the parts of such instruments as calipers, micrometers, etc.
Thread tool. (Mach.) A lathe tool round to the shape of the profile of the thread is to cut.
Three-and-four-fluted drills. (Metalwk.) Often used in place of roughing reamers. They are not suited to drilling from the solid, but are used to erilarge cored or punched holes.
Three-phase. (Elec.) Three a.c. windings or circuits differing in phase by 120 electrical degrees.
Three ply. (Furn.) Plywood built up, sing three separate plies.
Three-point suspension. (Auto.) A system of automobile-engine mounting in which the weight is carried at only three points.
Three-quarter binding. (Bookbndg.) Similar to half binding but with 'more leather showing.
Three-quarter floating axle. (Auto.) The rear-axle housing extends into the hubs of the wheels. The outer ends of the axle shafts are welded or keyed to the hub flanges, and the flange is bolted to the wheel hub.. Only one bearing is used on each wheel hub and if is mounted on the axle housing.
Three-square file. (Mech.) A term commonly applied to a three-cornered file; used for saw sharpening.
Three-tube colour camera. A colour-capable camera which produces a colour signal through the use of three pickup tubes, each assigned to one of the primary colours. An early stage inthe development of the colour video camera, introduced by RCA in 1940.
Three-way switch. (Elec.) A switch which provides for the control of a light, or set of lights, from two different points.
Three-wire circuit. (Elec.) A circuit of three wires giving a potential difference between the center
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