Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1047894
1 The present invention relates to an apparatus for sawing
a stone block into a plurality of slabs or smaller blocks, and
more particularly to such sawing apparatus of the chain saw
type suitable for efficiently cutting the large block of hard
stone.
Recently there has been sharply increased needs for slabs
of stone such as marble, granite and the like to be used for
flooring, walling and the likeO The rough blocks of stone
excavated and cut at the quarry are generally transferred to
the processing factory where said block is severed into a
plurality of slabs which may be finished by grindingO Or said
rough block is severed into a plurality of smaller blocks, and
then such block is further severed into the slabs.
In order to efficiently sever such large rough block of
hard stone, various apparatuses have been proposed and
provided, among which there are fundamentally two sorts, one
being reciprocally movable elongated blade type while the
other is circular rotary blade type.
In said former type apparatus, the elongated cutter
blade is reciprocally driven in the longitudinal direction
with urging towards the cutting direction generally downwards
for severing the stone block. In order to eliminate the ~-
làrger cutting resistance, there has been proposed an improve-
ment where the elongated blade is pivotally suspended at the
opposite ends thereof by two arms, each arm being pivotally
mounted at the other end thereof to the machine frame, so
that when reciprocally and longitudinally driving the elongated
blade by connecting one end of the crank arm to one end of
said blade, the other end of said crank arm being pivotally
unted on the pin eccentrically planted on the crank wheel, -
the elongated blade may be reciprocated with slightly swinging,
as shown in Japanese Patent Application Early Publication
~o. 125,988/1974 open on December 3, 1974. In order to - --
efficiently sever the block into a plurality of slabs, a
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l plurality of blades are parallelly arranged with a desired
space b~tween every adjacent two and mounted on a frame to
be driven as referred to above, which is so called the gang
saw. In the past, sandy abrasive for instance carbon silicate
such as Carborundum (trade name) was supplied together with
water to the cutting portion, but recently synthetic diamond
grits are deposited along the cutting edge of the elongated
blade so that severing work can be carried out without using
the sandy abrasive but with pouring water only. Such recipro-
cally driven elongated blade, however, generally necessitates
rather a long time for sawing the stone, above all hard
stone such as granite, even if diamond grits are used, as
well known to those skilled in the art.
In said latter type apparatus, the circular cutter blade
having a peripheral matrix embedded with particles of any
hard material such as synthetic diamond is rotatingly driven
for severing the stone block. The sawing apparatus for
this type is of higher cutting rate in comparson with said
reciprocally driven elongated blade apparatus. The rotary ;
sawing disk may be urgingly moved relative to the stone block
fixed still, or conversely the stone block may be urgingly
moved relative to the disk rotatingly mounted to the machine
frame. In order to efficiently sever the stone block into
slabs or smaller blocks, such sawing apparatus has been
proposed as having a pair of disk blades arranged side by side
in a common cutting plane so as to cut the stone block
concurrently from the opposite sides thereof, as shown in
Japanese Patent Application Early Publication NoO127,291/1974
open on December 5, 19740 The rotary circular diamond saw,
however, is unsatisfactory in that when the disk diameter is
increased for cutting the larger stone block the blade
thickness must be thickened for preventing eventual breakage.
The cost of such blade goes faster than the diameter of the
blade, as well ~nown to those skilled in the art. Furthermore
there i9 naturally a limitation of the cutting depth due to
that the shaft for driving the disk must be mounted at the
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center thereof. Consequently the relatively large stone block
can not be processed by means of this type saw.
Thus the principal object of the present invention is to ;~
provide the stone sawing apparatus capable of severing the
large block of the hard stone efficiently into a plurality of
slabs or smaller blocks.
Said object and other objects as well as advantages
attai~ed by the invention which will be readily appreciated by
studying the following explanation, can be attained fundamenta-
lly by providing an endless chain belt around which metallic
matrix segments on which diamond grits are depositted are
fixedly mounted, which chain belt being extended between and
over a driving sprocket wheel and an idle wheel so that the
running lower chain belt portion may sever the stone block
laid therebeneath~ Said driving sprocket wheel and said id~e
wheel are respectively mounted on the concerned bracket fo~
rotation, each bracket being mounted on a vertical post for
s~idingly movable therealong.
The invention shall be explained in more detail in
reference to the accompanying drawing; in which
Fig. 1 is a schematic front elevation of the apparatus
of the invention, and
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Fig. 2 is a schematic perspective viewO
In the first place it should be noted that said drawings
have been considerably schematically made for the sake of
clarificationO The stone sawing apparatus has a machine
frame represented generally by 10 which comprises a plurality
of transversely extending lower beams 11 and a pair of
longitudinally extending lower beams 11' so as to form the
base frame work on the floor. Along each of said
longitudinal floor beams 11' there is provided a rail 11" so
that a wheeled carriage 15 loaded with a stone ~lock 30 may
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run along a pair of said rails 11". A pair of vertical posts
12, 12' are installed so that the lower ends thereof are fixed
respectively to the upper surface of said transverse lower
beam 11 and a diamond chain represented generally by 20 is
extendingly mounted for running between said two vertical
posts 12, 12', of which upper ends are fixedly mounted with
a transversely extending upper beam 13. In the illustrated
example only two chain saws are shown, but actually ten chain
saws and consequently ten fr~me works as referred to above
were provided so as to sever the block of 1.5 m. height x 2 m.
width x 4 m. length of franite from Paochon,Korea into
eleven smaller stone blocks. Since the two outer blocks
cannot be the product, the nine blocks, each of about 40 cm.
thickness, were obtained~
The chain saw 20 comprises an endless chain belt 21
extended between and around a pair of chain sprocket whe~ls
22, 22' the former of which is mounted on a bracket 23 for
rotation while the latter is mounted on a brarket 23' also
for rotationO Said brackets 23, 23' are mounted respectively
on said vertical posts 12, 12' to be each vertically slidingly
movable along each of said posts. On said bracket 23, there
is mounted an electric motor 24 of 100 hp. in the embodiment
so as to drive the sprocket wheel 22 and consequently the
endless chain belt 21 in the running rate of 500 m/min. in the
embodiment. The sprocket wheel 22~ is of idle wheel~ The
distance between the two axes was made to be 205 mO in the
embodiment.
The chanin belt 20 can be of any construction9 but the
usual link chain was used in the embodiment which comprises a
plurality of link plates in pair so that each two adjacent
pairs are linked by means of a pin. Along the outer
surface of said endless chain belt, there are fixedly mounted
a plurality of segments 25, each being of 12 mm. width and
10 mmO length although such dimensions may be varied
depending on the dimensions of the chain elements. Said
segment can be prepared by using synthetic diamond grits to
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L be metal-bonded by any suitable method well known to those
skilled in the art of diamond grit tools, for instance by the
so-called pressure sintering method known in the powder
metallurgy field. Each segment can be fixed to a length of
the pair of link plates for instance by solderingO In the
embodiment the diamond segments of each 10 mm length were
mounted by every 40 mmO space between the two adjacent segmentsO
In order to guide the chain belt 21 for stable running, there
is preferably provided a guide plate 26 as well known in the
chain saw for cutting the treesO In the embodiment, nine
granite blocks of 105 m. x 2 m. x 40 cm. could be obtained
from said large stone block in an hourO
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