Needle Valve
A valve for controlling the flow of a fluid, usually consisting of a stem provided with a more or less tapered point, adapted to tightly fit in a somewhat conical seat. When the stem is thus seated the flow of fluid is cut off, and, as the tapered end of the stem is gradually withdrawn from its seat, a passage is progressively opened, the area of which is capable of close regulation. Used in carburetors, lubricators, gasoline shut-offs, gas tanks, etc.
See carburetor needle valve and carburetor float valve.
Negative Plate
That plate of a battery cell into which the current seems to flow from the external circuit. In a primary cell this is the carbon or copper plate and in an accumulator the spongy lead or iron-oxide plate.
Negative Terminal
That terminal of any electrical apparatus into which current seems to flow from the external circuit.
Neutral Position
That position of the mechanism of a sliding pinion change speed gear in which no driving effort is transmitted from the rotating motor to the wheels, although the clutch is in engagement, for the reason that no gears are in engagement. Also the position of the gear shifting lever, which corresponds to the above described condition in the gearset.
That condition of a planetary or individual clutch change speed gear in which no clutch is in engagement and the position of the control devices which correspond therewith.
Neutralize: (v.)
To place a change speed gear in the neutral position.
Nickel Babbitt
A white metal of which bushings (q. v.) for bearings are made and for which the following is a specification: Copper, 64 per cent.; tin, 5 per cent; lead, 30 per cent., and nickel, i.e. per cent.
Nickel Steel
See steel, nickel.
Nickel Chrome
Steel See steel, nickel-chrome.
Nipple
A term specifically applied to the points of attachment of the branches of an intake or exhaust manifold (q. v.), which are properly formed to fit in their respective port openings, the joints being either ground tight or packed by gaskets and held in place by clamps or otherwise. Also a pipe fitting consisting of a short length of pipe threaded externally at both ends.
Non-Conductor Electric
A substance through which electricity cannot appreciably flow at ordinary electrical pressures. Used in electrical devices to prevent the escape of electricity from the wires or other conductors to which it should be confined. Glass, porcelain, rubber, mica, vulcanized fibre and silk are among the best non-conductors. Synonym: Insulator, dielectric.
Non-Fluid Oil
See grease.
Non-Freezing Solution
See anti-freeze solution.
Non-Return Valve
See check valve.
Number Plate
A plate, usually of sheet steel, conspicuously inscribed with the registration number of ‘a car and the name of the State in which it is registered, two of which are usually required by law to be carried at all times affixed respectively upon the front and rear of a car so that the ownership of the car may be readily ascertained by reference to a list of registrations. The rear number plate must be illuminated at night by the tail lamp, according to most automobile laws.
Synonym: Number Pad.
