होम Scientific American A Machine that Saws 240,000 Wooden Paving Blocks in a Day

A Machine that Saws 240,000 Wooden Paving Blocks in a Day

यह पुस्तक आपको कितनी अच्छी लगी?
फ़ाइल की गुणवत्ता क्या है?
पुस्तक की गुणवत्ता का मूल्यांकन करने के लिए यह पुस्तक डाउनलोड करें
डाउनलोड की गई फ़ाइलों की गुणवत्ता क्या है?
खंड:
98
भाषा:
english
पत्रिका:
Scientific American
DOI:
10.1038/scientificamerican04181908-273
Date:
April, 1908
फ़ाइल:
PDF, 697 KB
Conversion to is in progress
Conversion to is failed
0 comments
 

अपनी समीक्षा पोस्ट करने के लिए साइन इन करें या साइन अप करें
आप पुस्तक समीक्षा लिख सकते हैं और अपना अनुभव साझा कर सकते हैं. पढ़ूी हुई पुस्तकों के बारे में आपकी राय जानने में अन्य पाठकों को दिलचस्पी होगी. भले ही आपको किताब पसंद हो या न हो, अगर आप इसके बारे में ईमानदारी से और विस्तार से बताएँगे, तो लोग अपने लिए नई रुचिकर पुस्तकें खोज पाएँगे.
1

Correspondence

साल:
1908
भाषा:
english
फ़ाइल:
PDF, 128 KB
2

Weather Vane with Attachment for Indoor Readings

साल:
1908
भाषा:
english
फ़ाइल:
PDF, 372 KB
Scientific A.merican

APRIL 18, 1908.

for blocks and the supply of old

A MACHINE THAT SAWS 240,000 WOODEN PAVING
BLOCKS IN A DAY.

son.

director of the municipal workshops

of Paris, has invented

a block-cutting

machine

turns out 24,000 wooden paving blocks per hour.

blocks are equally

i rregular, for paving is done only in the summer sea­

BY JACQUES BOYER.

M. Josse, the

273

These old blocks are scraped and trimmed for

further use in winter.

Furthermore, the demand for

blocks varies from year to year.

Mr. Josse, therefore,

endeavored to devise a machine that would accommo­
date itself to all these irregularities,

as

well as to the

sudden emergencies that are inevitable in

a

business

that
This

ingenious and complicated mechanical· device will ad­
vantageously replace the machinery and inetholis now
in use, effecting a considerable saving in wood as well
as in labor .
In the early days of paving with wooden blocks in
Paris, the blocks were sawed with single circular or
band saws. At a later period, in order to meet the
increased demand, three machines containing four or
five saws each were installed in the municipal work­
shop.

Each of these machines consisted essentially of

an oscillating frame, the lower end of which carried

'1

number of saws, to which the planks were fed singlY
by an attendant.

In

1900 this equipment became in­

sufficient, and some more expeditious method had to
be devised.

It must be

remembered

that

the

daily

output of a municipl!-l shop that turns out 25 million
paving blocks per year cannot be uniform unless ex­
tensive facilities for ustorage. are provided.

The trees

are felled only in certain seasons, and the regularity
of shipments is further impeded by the great number
of

purveyors

and

the

uncertainties

of

the

weather.

Sometimes the manufacture of blocks has to be sus­
pended for weeks, in order to take care of daily ar­
rivals of

R

20 or 30 carloads of planks.

The demand

View (If the Machine, Showing the Conveyor for the Planks.

n; :

�--� .------ �------�

Longitudinal Rection of the

Josse Block-Sawing

Machine.
of this character.

The result of his studies is a huge

machine 100 feet long, which divides each plank into
16 blocks by means of 17 circular saw!!.
The planks are brought to the machine on platform
cars, one of which is shown at the right of the dia­
gram.

The length of each plank is a little more than

sixteen times the height of a block, as it is laid in
the pavement with its fibers vertical

The width and

thickness of the planks correspond to the horizontal
dimensions of the blocks, when laid.

Two workmen

lift the planks, one by one, from the car, and lay them
on

a

conveyor formed of two endless chains E, con·

nected

by

transverse

cleats.

The

chains

run

on

sprockets 0 placed at the ends of an inclined frame A,
and

on

rollers D,

distributed

along the

somewhat convex surface of the frame.

upper
Two

and

sheet­

iron guides F keep .the planks in register and assure'
their proper delivery to the horizontal table, to which
they are elevated by the inclined conveyor.

The planks

are pushed along tbis table by combs K, of 16 teeth,
attached to two endless chains which run on sprockets.
The axes J J' of these wheels are mounted near the
ends of a horizontal frame G, which terminates in two

Emptying

the Skips of Pavi ng Blocks.

.& ll:AClIIlfE TRAT SAWS 240,000 WOODEN P.&vmG BLOCKS Ilf .&D.&Y.

shafts, one of. which is free to turn in bearings on two
posts H, while the other is supported by chains 1.

front of each tooth of the combs is

a

spring L.

In
The

274

Scientific Amerlca.n.

function of these springs is to keep the planks, before
sawing, and the paving blocks, after sawing, pressed
to the table. Near the

end of the table where the

combs and springs rise and abandon the blocks, the
latter are held down on the table by a set of small
wheels

M mounted on springs. Each comb

two 'little brushes which sweep all

carries

waste into holes

at the sides of the table.
The circular saws protrude through slits in the table.
There are 17 saws, about 25 inches in diameter, mount­
ed on three shafts, of which two are in line with each
other but not with the third, P.

This arrangement

APRIL 18, 1908.

Hitherto the forest has been damaged by large herds
of goats, which will not be prohibited from grazing in
future but will be under regulation. The protection of
the brush will conserve the water, which swells the
Salt River and its tributaries and will help to develop
the Salt River Valley.

latitudes of certain locations, that they could scarcely
be explained on the theory of errors of observation
due to defects in instruments or lack of accuracy in
observers.
But before saying more on

the aspect which the

matter has now assumed, it will perhaps be interesting

•. e· •

to glance a moment at the question of latitude as it

IS THE AXIS OF THE EARTH SHIFTING 1

appeared to the ancient Greeks. In the first place, cer­

BY J. F. SPRINGER.

It has been known for hundreds of years that the
axis of the earth is continually changing its direction.
To be clear .as to this, recall that there is a point in

tain of their philosophers distinctly taught the globu­
lar character of the earth.

They were familiar, too,

not only with the conspicuous daily apparent motion
of the sun from east to west, but with his annual

was adopted in order to avoid the excessive vibration

apparent motions north and south.

of a

day when he halts in the constellation Cancer, having

single shaft as long as the planks, bearing 17

saws and making 2,000 revolutions per minute.

The

accomplished the end of his northern journey.

s

long shaft could not be stiffened by intermediate bear­

They noted the

is the summer solstice.

This

An imaginary east-and-west

ings because of the small distance between the,. saws.

line through a point on the earth immediately below

It was therefore decided to distribute the. saws among

this position

three short shafts not in the same line.

Cancer.

Each shaft

of the sun they

termed the

Tropic of

It was said that a well in Syene was found

is mounted on ball bearings and is driven by two belt

to be such a point.

wheels, one at each end.

summer solstice the sun shone down the tube of the

The bearings rest on iron

Here at noon on the day of the

well.

Possibly it was from such an .observation that
Syene was supposed by them to be on the Tropic of

beams imbedded in masonry.
Directly under the saws, in the cellar of the build­
ing, is the main driving shaft, which carries six wheels

Cancer.

connected by belts with the wheels on the

as its true latitude, 24 deg. 5 min. 23 sec., does not

saw

shafts.

In this they did'not make such a great error,

The driving shaft is mounted so that it can be moved

differ two-thirds of Ii degree from the true latitude of

up and down, to loosen and tighten the belts.

the Tropic of Cancer.

This

adjustment can be made from the main fioor.

Figs.

The saw blade is made up of a number of hinged
cast-iron plates, which can be turned back for exami­
nation

and

adjustment

of

have direct lubrication.

the

saws.

The

bearings

The resinous kert which the

saws accumulate from pine wood is removed by fine
jets

of

kerosene

pumped

from

a

five-gallon

tank

through 3 main and 34 branch tubes and occasionally
thrown on both faces of all the saws, without stop­
ping the

operation

of the

machine,

by

opening the

1 and 2.

Using the Tropic of Cancer as a reference line, they

the northern sky which we term the north celestial
pole and which will remain unchanged in .its position
to-night, although all the stars are apparently moving
from east to west.

H owever, they estimated it at

24 deg.

There is no visible star occupying

exactly this position, although the North Star approxi­
mates it. But this pole of the heav€ns is continually
passing through a change in location.

The terrestrial

were able, by means of an instrument which may be
termed a hollow gnomon, to determine latitudes north
and south. This was a hemispherical shell having a
rod directed radially from the lowest point of the inte­
rior of this cup-shaped piece of apparatus.
terminated

at

the center

of the

sphere,

This rod

and

quently was of the same length as a radius.
on the day of the summer

solstice,

the

conse­

At noon

north pole

cocks of the three main tubes that supply the three

would-as we know-be directed toward the sun, as

sets of saws.

shown in Fig. 1. A line from the sun to the center of

Each of the two sets of saws which are in line con­

the earth would pass through the Tropic of Cancer, O.

tains 5 saws and cuts from the plank a :waste end or
trimming and 4 pavJ.ng blocks. These two sets attack

P, the hollow gnomon is fixed in such pOSition that

the plank simultaneously.

its central rod is vertical;

If it be desired to determine the latitude of a point

The middle portion of the

that is, is

continuation

a

plank passes on between them to the third set, which
comprises 7 saws and divides the remnant into 8 equal

of a radius of the earth.

blocks.

the center of �he shell, this arc is the measure of the

the moment of noon. It is the arc P Q.

The Hi blocks which are thus cut almost sim­

ultaneously from the plank continue to advance along
of the conveyor and

the table, pushed by the teeth

angle

Since T is

As the sun, S, is very far away, the lines

a.

ST and S 0 0 are practically parallel. ,Consequen tly,

come under

held down by the springs L until they

Its shadow is observed at

the angles

a

and fJ are equal.

The number of degrees,

the . spring wheels M, where they remain until they
are pushed onward by the following set of blocks.
Thenceforward the blocks advance by steps, as they

then, indicated by the arc P Q is the same as the num­

new

to have been used by the Chinese as early as eleven '

are

pushed

onward

by

arrivals.

the end of the table they slide

reach

When

ber indicated by PO.

But this latter arc represents

the latitude of P from O. This instrument is supposed

they

down two in­

hundred

clined planes,. divided into 16 compartments by verti­
cal partitions, to the three belts of a horizontal con­

years

before

Christ. Wh,ether

or whether they invented it

veyor, from which they are picked up and thrown into
cars by a crew of 8 workmen. The cars, when filled,

known.

anew, is

But they were not limited to this one instrument.

The power which operates the saws is furnished by

sun is immediately over the equator at the moment of
noon.

stalled in the basement and connected by two belts

with this instrument was to be taken.

This motor is controlled by
on

the

main

floor are two additional interrupters, an amperemeter,
a voltmeter, and the controlling apparatus of a 4 horse­
power motor U, which supplies power to the convey­
ors.

Finally, there is a traveling crane and windlass

for the removal of the saws for resetting.
The Josse machine can saw 25 planks per minute.
As each plank furnishes 16 blocks, the theoretical out­
put of the machine in

a

are technically known as precession and nutation.
near

the

close

of

the

last

century,

certain

astronomers began to suspect that not only was the
'axis of the earth continually
relatively to

changing its direction

the stars, but 'that

it was 'undergoing

changes in the body of the earth itself. That is, they

day of 10 hours is 25 x 16 x 60

o�oo

+-o� 10

x 10 = 240,000 blocks.

-0:/0

of pavi�g blocks can be turned out in a day with the

D,'fO

and fJ would be

from the equator.

Consequently, by determining the

valne of a ,by means of the lengths of the indicator
'
P T ,and the shadow P Q, we should arrive at the value
sought.
If one desires to satisfy himself how closely they

indicated by a good atlas with the following latitudes
as given by Hipparchus:
Syracuse

................... 36 deg. 44 min.

Byzantium

(Constantinople).. 43 deg.

Massilia (Marseilles)..... .... 43 deg.

Ne_ National Forest In Arizona.

It will be observed that the ancients were able to

A new national forest, named the. Verde, and con­

use these methods only at certain particular mQments.

sisting of 721,780 acres, has just been created in Mari­

In modern times, latitudes may be determined at any

The forest lies

on the wes t side of the Verde River and constitutes' a
great part of its watershed. Jerome, where the United

time of the year.
ods.

the pole

of

the

heavens,

E is a point on the equator. Consequently,
NO is perpendicular to 0 E. If no great accuracy is

west and southwest of Jerome are the Mingus Moun­

desired, the north star may be considered as the celes­

Most of the reserve is covered with brush that

chantable timber on it and, under proper management,

N is

Fig. 3.

To the

has no commercial value; but a small part has mer­

Th( re are quite a number of meth­

But the followiug is qnite simple, and will be

readily understood.

Verde Copper Mining Company has its headquarters, is
in the northern part of the new forest reserve.

will supply the neighboring mining camps.

a

But fJ determines the latitude of P

Athens ... .................. 36 deg.

aid of 20 men or less.

tains.

a radius of the earth, the angles
equal, as before.

methods of modern science, let him compare the values

-O:�O

for unavoidable stoppages, etc., but a small mountain

gnomon set up at P having its indicator in line with

approximated to the values determined by the refined

-d20

In practice it is necessary to make some allowance

copa and Yavapai counties, Arizona.

The line S 0,

would pass through a point on the equator. With the

motions which give rise to the movement of the pole
But

It is at such an instant that the observation

Fig. 2, connecting t h e sun and t h e center of the earth;

Fig. 3.

a liquid rheostat W, with an amperemeter and a safety
switchboard

Upon the

days of the vernal an� the autumnal equinoxes, the

an electric motor U of 110 horse-power, which is in­

a

not certainly'

By this means, Eratosthenes determined the

Another form of gnomon had a plane base.

go to the storage yards.

cut-off. Connected with

Greeks

latitude of Alexandria.

are hauled over the Decauville railway tracks to the
creosoting 'establishment, whence the creosoted blocks

with the main shaft P'.

the

obtained their knowledge of it indirectly from them,

'l-O.£:O

0,00

+0.'10

Fig.

The pro­

-O�/O

tial pole.

-O:cO

instrument.

The angle

rp, is observed with a suitable

That is to say, the elevation of the north

star above the horizon is taken.

4.

Now 0 P is perpen­

dicular to one side (P H) of rp, and 0 E is p erpendicu­

tection of the brush-grown area is just as important
as that of heavily forested land, the scrub being the

saw reasons to think that the geographical point on

lar to the other side P N (P N being practically par­

only thing that

the

the earth called the north pole was shifting its posi­

allel to NO on account of the great distance of the

The pro­

tion over the surface. This would mean, if true, that

star).

the latitude of New York city is not a fixed quantity.

those of rp.

conserves

the water and

watershed of the Verde River from erosion.

saves

tection of this watershed from damage by overgrazing

That is, the sides

of {} are

This gives () = rp.

perpendicular to

But {} determines the

and wasteful lumbering is necessary in the opinion

The, reasons for entertaining suspicion in this matter

latitude of P from E, the equator. So then, the eleva­

of the officers of the Reclamation Service to the de­

arose from the fact that variations of such number and

tion of the north star above the

velopment of the irrigable lands of Salt River Valley.

character

zon is exactly the same as the latitude of the place.

came to light

in redeterminations of

the

(astronomical) hori­

IENTIFI£

MERI£AN

[Entered at the Post Office of New York, N. Y., as Second Class Matter. ' Copyright, 1908, by Mnnn & Co.]

[

NEW YORK, APRIL 18, 1908.

The Sawin)!: Table.

'fhe Horizontal Bed Has Been Lifted to Show the Arrangement of the Circular Saws.

A MACHINE THAT SAWS 240,000 WOODEN PAVING BLOCKS IN A DAY.-[See page

273.]

10 CENTS A COPY
$3.00 A YEAR.