1948-07-22 — Page 8

Page B

THE CHINA MAIL, THURSDAY, JULY 22, 1940.

Pulsometer Engineering E. Lu

CENTRIFUGAL, ROTARY,

TURBINE AND VACUUM PUMPS.

Sple Apenta

THE JARDING ENGINEERING

CORPORATION LTD.· ́

14-16 PEDDER STREET, HONG KONG. TELEPHONE 30311.

THE LINCOLN

SHIELD ARC WELDER'S

WELDING EQUIPMENT

FLEETWELD ELECTRODES

STOCKS CARRIED

BY

J.P. INGLIS & SONS LTD.

CORNER CHATHAM and MATAUWEI RD. KOWLOON.

TEL. NO. 58054 Representative For South China and Hong Kong THE LINCOLN ELECTRIC CO. AUSTRALIA, PTY. LTD.

Thor

ENGINEERING PAGE

MODERN PRECISION MEASURING

INSTRUMENTS

Modern methods of repetition manufacture of high-grade en- gineer-produced goods depend largely on the use of precision

By Robert Hutcheson

dimensional - Irregularities of workpiece being gauged are used to cause slight electrical effects, and these are mamiled so that

of a

mensuring equipment. Because ing. 250 nduntions, instead of and the work being gauged and, they can be indiented clearly on parts of motor-cor engines, the 25 graduations of the ur-therefore, the rate or volume of some type of meter, which is Vacuum cleaners,

refrigerators dinary hand micrometer reading air escape for the variation of calibrated in units of the dimen- and electric Instruments must it to. 0,001 Inch,

pressure in the air system due to plans together without selective assem- Accuracy of micrometer instru- this escape of air), is a measure on it is desired to check. For bly they must be accurate to menta reading to 0.0001 inch the difference in size of the example, movements of a gauging within close limits, the

member, dus dimensional differ- actual must not

depend on the user's work and gauge. So if some type ences in work under test, can be limits depending upon the class sense of touch, and this condi- of indicator is included in the air transmitted 10, an electrostatic of product. In order that com- tion is met by the use of aayetem to show variations in the condenser, the capacity of which poncht accuracy con be obtained

"Aducial indicator." When the pressure, speed or volume of air will thereby be Varted. This It is essential that figs, tools and Instrument is set, the indicator dowing through it, this indicator variation in capaelly is used to workshop gauges used in their reads zero, and it will give this can be calibrated to represent the nonco electronte devices so production should be accurate to

reading when the correct gaug-dimensional differences that cause that very small movements of the within even closer limits. It is

ing pressure is applied to the the variations in the air flow.

gauging member are magnified again, essential that gauges and

and work. The

Pheumatic gauging equipment into the large movement normally fixed jaw other measuring equipment used of the instrument is connected to of this kind is sensitive in making those Jigs and work- the indicator and is actually mov-dimensional differences or the pointer on an indicator, shop gauges should be even more able under

order of .000003 inch and the ac Optical Instruments pressure imposed on necurate. Thus the final

it during measuring. Various tual gauging elements are prac ference gauging equipment must types of indicator are used such tically free from. wear. The "wo kinds of optical measuring have its accuracy judged in mil.ne dial indicators end electrically equipment also has the advan-Instruments among other are lionths of an inch.

controlled indicators..

tage that any type of gauging those using microscopes,

tele- Another

aspect of

clement such as modern

a plug gauge, scopes, and greticules; and those' gauging is that many components

snap gauge or ring gauge can be relying on Interferometry, in are produced in thousands by re- petition methods-their rate of production is high and the cost of production comparatively low, Therefore if these parts must be gouged, it is necessary to check large quantiles of components rapidly, and cost of gauging must be kept down to a figure com- mensurate with cost of actual production.

Here are some details of the main types of measuring lastru- ments in use today.

Micrometer Screw

Dial Gauges

There has been a decided in- crease during the past decade in the use of dial gauge instruments, and today Britain leads the way in the manufacture of these high- grade tools.

These instruments vary in their multiplying mechanisms, which range from purely mechanical movements to arrangements up

Most optical lever. ing the makers supply gauges of different grades of sensitivity; for instance, dial gauges which differ out- wardly in their graduations vary inwardly only according to the ratio of the multiplying mechon- Instruments embodying Lem, gauges which are somewhat micrometer screw were one of the similar in outward appearance earliest attempls at real precision may, therefore, read to 1001 Inch measurements about one hundred over a range of .030 Inch, to .0005 years ago Sir Joseph Whitworth inch over a range of .020 inch or was building measuring machines to .0001 inch över a

range of reading to 0.000, and 0.000001004 inch.

ՄԱՀԱ inch in which micrometer screws Instruments of this type are having 20 threads on inch were not limited to tonlrooms and in- employed.

departments; their Instru- spection ments are used extensively to robust construction and case of day, the usual, pitch being 40 use have led to their very wide

The dial

Microneter

threads an inch. Most measur- use in production shops. Ing machines with micrometer

gauge can be incor- screws read directly to 0.0001porated in many special gauging

mind in Inch with the aid of large-diu- Axtures, and it is no uncommon meter thinbles or drums carry thing to find receiver-lype gaug- ing fixtures embodying half-a- dozen dial gauge for the simul- taneous checking of a component on as many separate dimensions.

PORTABLE POWER.

TOOLS

PNEUMATIC MINING & CONTRACTORS (Sinker“Rock Drills.

TOOLS:-

PNEUMATIC TOOLS:

(Stoper Rock Drills (Paving Breakers (Clay Diggors (Tampers (Etc.

:- Drills

Wood Boring Machines ·

Nut Sottors

Rotary Wronchos Impact Wrenches

Grinders

Sandors

Wire Brush Machinos Caulking & Scaling

Hammers

Weld Flux Scaling

Hammers Riveting Hammers Rivat Squeezers” Riyet Busters Holders. On

PORTABLE ELECTRIC TOOLS:— (Drills

(Toppers

(Hammers

(Grinders

·(Nibbler

Valve Shops

Stocks of selected tools and accessories will be carried as from middle of July

YU TUNG TAI LIMITED,

218- Queen's Building.

ENGINEERING DEPARTMENT,

Distributors

Air Gauging

Air gauging in a very useful system to adopt when large num», bers of components are to

be

What Is balleved to be the smallest combination safe in the world has been produced in Britain. One of the unfo's most interesting features le that the owner works out his own combination

Fur-

coupled to an indicator. thermore, it is not always, neces- sary to

use a large number of gauge clemonts to suit a range of tolerances around one nominal dimension; one element,

which will pass the work, can be em- ployed, and the limit indexes set

Perkins

DIESELS

F. PERKINS LTD. Typo S6M Marino Diesel Engines 100 HP-2,000 RPM

which a wavelength of light is Complete with reverse gear and 2 to 1

unit of measurement.

An Instrument in the first class depends upon the use of a scale graduated with an extremely high degree of accuracy, and is em bodied in it as a graticule. This raticule

can be used for direct measurement by the observation against it of an image of the work, On the other hand, it may be used in setting or reading. main scale, such as on the rotary member of a dividing head, in which case it is used to subdivide the divisions on the main seale, Circular tables for tool-room use are now made in which a micro- scope of this type gives readings to two seconds of are.

In the second class of instru- ment interference bands are ob- served, by means of an optical nat, for example. By Inter- | ferometry it is quite easy to make

measurements to 0.000003 inch,

Surface Roughness

Surface Anish has an important bearing on the efficiency and life' of machine parts. that move on

reduction gear Available for early delivery.

Solc Agents:

GILMAN & COMPANY, LTD.

ENGINEERING 'DEPARTMENT Telephone 33401.

The SINCERE Co Ltd.

one another. Several surface HONGKONG'S GREA EDEPARTMENT STORE

analysers have been developed during the past decade or so to measure this finish

Depth of surface roughness is nousured in micro-inches, and it of necessary to note depth roughness and the pitch or tre- quency of the hills and dales.

Surface finish can be measured by interferometry, but most com- Use stylus mercial analysers

gauged, because the actual gaus", | accordingly on the indicator. which traverses the surface to be.

ing elements or anvils employed are almost completely free from wear; this system of gauging de- pends upon the existence of a clearance between the gauge and the work.

Electronic

Measurement

tested. The up and down move- ments of the stylus are multiplied and recorded on a chart on which depth of roughness is plotted against travel of the stylus over the work.

Electronic devices open up vast 1-ossibilities In engineering mea- The gauge itself is hollow, and surement. It is possible thai

When the engineer demands is 'connected to nˇsource of com- they may even aller completely greater accuracy, the me

metrologist pressed air which can escape existing ideas on measurement. gives him the instrument to meet ihrough one or more orifices in Great sensitivity, and freedom his needs. The science of mea- the gauging faces of the gauge. from parts subject to mechanical surement is, therefore, by The escape of air through such wear, these are the two main means. static but expanding con- Jan orifice depends on the clear virtues of electronic gauging tinually, bringing to its aid al- ance between the gauging facel apparatus. Broadly speaking, I most every branch of physics.

New Process For

Making Newsprint

Deep in the jungles of Central In-out the world. He said that they re diz project is underway which may quire about 10 year to reach full affect world prices of newsprint. growth and are being sued

A

faiter

new process has been discovered than they can be replaced. for making newsprint 40 per cent. Nelr's discovery resulted from cheaper than the cheapest methods wife's demand for cheap papar, now used, according to P.N. Nsir, of October, 1943, she established Bombay.

press syndicate whose aim was

Prefabricated Grandstands

Scientific Shoe-Fitting

no

As a result of an investigation by the British Boot, Shoe, and Allied Trades Research Associa- shoe fittings for women has been tion, a precision-graded range of produced. A special instrument enables the correct fitting to be taken by a retaller in short time, and the 31 attings of very la the new system equalings. the full ." range: (120) of American the Another

bis

apparatus designed by

and the

NEW ENGINE

The secret lies in the "Jet-propell. | publication of cheaper books for 1p-electric aw development is an i ed free which grows 60 feet in 15 dis. Three years later, the high the same association for provid years. There is sufficient quantity of, cost of paper had made most booking data about lasts and this hardwood, tree, known as the 130. expensive for most. Indiste. So serviocability of the shoes pro- Broadleaf," to supply India's news-Mis. Nair dedded they must beduced on them. Shoes to be print needs for 120 years with no printed on the cheapest paper news tested are fitted, with metal discs referesting, Nais sald

print. She asked her husband to help, connected to the instrument. The of the world newsprint is her.

wehrer walks along metal manufactured from the pulp

strip, of "He began his research. He found and the apparatus produces poly- coulfezous trees liko spruce and Ar. that spruce and fir grow, in India gonal outlines showing points of Supplies of these trees, according to but only on the uppermost heights of contact of the shoes with the [„Nale, ale" becoming scarce through the Himalaya, Mountains. The ground in:sequence from heel to would toe, and the duration of contact. peuse of using these trees be probibuifve. Co · Nair. ex: [„Aniklýsla of the record tells whe- perimented with Indian hardwood ther guit is goed or bed and trees, In December 1946, he found whether the shoes give stability the answer.

-- or instability. Hle sent his Radings 1 to laboratory in Canada for testing, and received their congratulations, within ļa fèw, weekì. „The: Government, ófi

India published report en his The first training aircraft in the

· One novel exhibition in the Bir- proces in April 1947, which agreed world to be fitted with a' gas mingham section of the British that newsprint could be poller was demonstrated at Rugby, could be made in in- turbine engine which drives a pro- Industrite Fair was a new type 'dia.N of prefibricated grandstand.

The tres

which Nale's F precess England, last weak. It is constructed in unita of 10 Chinese for paper manufacturing a

unea is the name one- und, by, the This three-senter, all-metal air-

tho Boulton knd Paul

"Bal- feet frontage, each accommodating thousand year ago. It grows in 5,000 Ital" gave an excellent impression 40 persons in folding tubular square miles of forest is the Central of its manoeuvrability and hand- chairs and capable of extension to Provinces of India. Can Mega Ling qualities. The engine install. any length by the addition of The National Newsprint and Pa- eden Armstrong Siddeley further unile.

per Milia Ltd., is being erected at

which, in common with The now unit grandsland Chandul, once village with I po all Jet engines, much constructed of tubular ecanolding pulation of 35, in the Central pro- quister than the piston engine and made of rust-proofed, high', duly

The Government of the Can- free from vibration. The Bailloi aluminium alloy, which Lakhs of Rupees in the rails. It bar per hour and service calling of provinces had invested 2.10 | has a top speed of over 300 miles leased 100 square "milles to the com- pearly 40,000 feet.

London, Apr. 17.

| strong as "aleet yet only.. one-third

craft

Its weight.Emphasis in the depar for the plant and an experiment. The manufacturers

sign: of the unli^)

is is on simplicity

Boulton

of erection and cars of transpars platisilon with Ishéjannan, ang acre, and Pau Airirart of Wolverhamp tation so that handling: Costs are sanually, it well) be paid a royaky on top-report that numerolių enquleur redused to the skrolilla mirstumas pavery.

Dem" received already Fandchan: contracted" to build tromi kitované itories including Company: otă Tudor, rukun and kamalli koraani, stadium. CARRAY

(Noribery / Steel S Seacrolimus for falied/fatheiten: off them have

SOLE AGENTS

FOR

Farnsworth

RADIOS

KNOWN. FOR TONE

PHILCO

AIR-CONDITIONERS

Again Available

Sole Distributora::/

GILMAN & COMPANY LTD.

REFRIGERATION; DEPAR