Note: Descriptions are shown in the official language in which they were submitted.
~7~n~2
70201-14
~N AUTOCUTTING EXTRUSION MACHINE FOR PRODUCING
PRESTRESSED CONCRETE CORED ARTICLES
This invention relates to an extrusion machine with
spiral conveyor for forming concrete or other modable materials,
and by the addition of cutting and core-plugging mechanism, being
able to produce automatically and directly single (narrow and
wide) slabs of the required size and specification.
Prior technology of extrusion machine for producing
prestressed concrete cored slabs, and the present invention of
extrusion machine for producing prestressed concrete cored single
slabs (including wide slab extrusion machine and narrow slab
extrusion machine) have both been used for the production of
prestressed concrete cored components. By integrating the deliv-
ery, extrusion and vibration processesJ concrete slab can be
produced requiring no timber, economizing cement and steel consum-
ption, rendering high strength and sound quality as well as
raising the working efficiency by 4-6 times in comparison with any
other prior methods. The development of extrusion machine creates
a requisite for the realization of factory-processing (i.e. so
called housing factory) in building construction.
For nearly two decades, many interested parties both in
China and abroad, have spent substantial man-power, material and
financial resources in actively undertaking the research of extru-
sion machine. In the early 1960's, Canada was the first to
successfully complete the research in the type of extrusion
machine that utilitizes the spiral conveyor for forming concrete
components. Since then, the ~nited States, Britain and the Federal
-- 1 -- `. ,, ~,
P2720~L~
Republic of Germany have also achieved successively in their
respective researches of the extrus:ion machlnes having various
characteristics, for which several patents were granted,
including those published such as, Canada Patent 985191 (1974),
U.S. Patent 4273522 (1979), Eurpoean Patent 080333 (19~2), etc,
Nevertheless, there are disadvantages in all of these machines,
including: (1) hopper is incorporated in the machine, that causes
vibration to the concrete aggregates and their ultimate
agglomeration, and also increase in the weight of machine; (2)
specially constructed casting beds are needed, with each being
able to produce only one type of slab corresponding in size and
specification; (3) worm gear, worm shaft and chain transmission
system is being used to result in low efficiency of the machine
(below 50%); and (4) the high cost of spiral conveyor which poses
a poor economic effect.
In 1977, Ren Deguo etal, of China succeeded in their
research for a new type of extrusion machine which overcomes all
of the above-mentioned disadvantages. The new machine is provided
with the following characteristics: the hopper is separated from
the main machine and supported by four posts directly in contact
with the ground, with rollers employed for pushing the hopper
forward, thus eliminating not only the agglomeration of concrete
but also the need of providing any crushing mechanism (or feeding
mechanism); by the use of restraining devices in front and at
intermediate parts for positioning and guiding of reinforsing
steel, and together with the elemination of special casting beds
by the substitution of flat concrete grounds for production, site
z
utilization rate is upgraded and construction cost is lowered; by
using the fully-sealed transmission mechanism with all slanting
mult level deceleration and multi-axial output, efficiency rate of
the machine can be greatly upgraded (up to 86%) thus reducing the
energy consumption; and the use of a new type of spiral conveyor
which is high in strength and well-resistant to wear, with each
piece of convyor having a performance capacity of 20,000 meters in
travelling-distance.
In spite of its many advantages, this new type of extru-
sion machine is similar to other extrusion machines in that the
cored slabs produced are all elongated or continuous plates,
whereas the actually required cored slabs are rectangular ones
having certain specified lengths. The common practice of dividing
the elongated slabs is to cut them into sections corresponding to
the desired sizes. Known methods of cutting comprise the rigid
cutting and soft cutting. Rigid cutting is carried out when con-
crete reaches its ultimate strength of 70%, and by using saw-blade
formed of welded diamond chips, concrete and the reinforcing steel
are cut simultaneously. The disadvantages of this method are: (1)
high in cost, (2) without spare or swing-back steel on either ends
of the slab, and (3) the susceptibility to cracks due to contrac-
tion during the hardening of the elongated slab, resulting in the
increase of wastes. Soft cutting, on the other hand, is carried
out when the cored slab has just been formed, and with manual
operation (by raking or sawing) to divide a part of the concrete
component into required sections (reinforcing steel being kept
uncut temporarily). The disadvantages of this method are the high
7~:0~2
consumption of time and labour, -the heavy manual work, as well as
the nonavailability of the degree of roughness at the ends and
discrepancy in size length. ThereEore~ both methods are not ideal
for application.
The width of cored slabs currently in use is basically
equal to or smaller than 1.2 meters. ~y arranging these narrow
slabs to form "wide slab" will have the disadvantages of: (1) the
discrepancies in prestressing controls existing in different slabs
will form a kind of uneven ceiling; (2) grouting of seams is rela-
tively difficult and the appearance of cracks is more common;
(3) the efficiencies in transportation and construction are rather
low. Large size slabs currently being used in China may overcome
certain disadvantages as the above-metioned, but still have the
defficiencies of being heavy in weight, high consumption of
concrete and steel, as well as low performance in sound and ther-
mal insulation. Thus, the solution of the problem of producing
large size cored slabs with high efficiency machine has become an
urgent need to the present day construction industry, and also the
one of practical significance.
The aim of the present invention is: by the additional
provision of a mechanism with cutting and core-plugging functions
so as to enhance the extusion machine to become capable of
automatically and directly producing single slabs (narrow and
wide) in comformance with the required size and specification,
thus solving the problem existent in the above-mentioned prior
technologies. The said mechanism will be able to cut the cored
slabs just formed by extrusion into sections, with cores on both
1~7201Z
70201-14
ends plugged, and at the same time can have plugs performed at
several intermediate places of the wide slab cores, thus forming
transverse ribs to function for the fixing and protection of
reinforcing steel as well as to increase strength of the wide
slab, resulting in the automatic extrusion and forming of large
size cored slabs.
The present invention provides an extrusion machine for
maklng prestressed concrete cored slab sections, the extrusion
machine comprising: movable support means for extruding an
outside surface of a molded concrete slab; a splral conveyor
rotatably mounted to the support means for transferring and
compacting concrete wlthin the movable support means and producing
cores in the molded concrete slab; drive means for driving the
spiral conveyor, the drive means being supported by the support
means; posltlon-restraining means for guiding the extrusion
machine along a pathway on a work surface on which the concrete
cored slab is being formed, the posltion restralning means being
operably assoclated with the movable support means; a movable
hopper for feeding concrete to the movable support means, the
movable hopper having support means for providlng independent
support and movement of the hopper wlth respect to the movable
support means, wherein the movable hopper ls operably associated
with the support means; and cutting means having core-plugging
means attached thereto for cutting the molded concrete slab into
sections with the cores of each section being plugged at both
ends. In the production of wide slabs, such as slab wldth
surpassing 3.3 meters, besides placlng transverse reinforcing
7ZO~
70201-14
steel at the ends and with the ends plugged, transverse steels are
al~o placed at the intermediate posltions of the slab and wlth
such positions plugged to form transverse ribs. Such transverse
ribs will render the required strength to the wide slabs. The
width of a wide slab extrusion machine ls determined by the width
of the large size cored slabs to be produced, while the number of
splral conveyors to be used may have as much as 30-36. In
structure, the wide slab machine essentially resembles to tha~ of
the narrow slab machine.
Preferably the cutting and core-plugging means
comprises: a cutter blade slidably mounted on the movable support
means; cutter blade drive means for driving the cutter blade, the
cutter blade drive means being mounted to the movable support
means; a cutter blade vibrator; and supplemen~al concrete feed
means for providing additional concrete at positions at the cores
where the slab is cut by the cutter blade for plugging the cores.
The mechanism of cuttlng and core-plugging for a wide slak machine
is slightly different from that for a narrow slab machine, in
which the supplement feed device is mounted on the side of cutting
blade whereas that for the wide slab machine is mounted on the
bottom of one side of the supplement feed slide plate, the lower
end of which is flush with the lower end of the supplement feed
device. Such a structure will ensure that when ribs are belng
formed at the lntermediate places of the large slabs, the machina
would not cause to cut off the slab formed.
The following is a description by way of example of
certain embodiments of the present invention reference being had
Z
70201-14
to the accompanying drawings in which:-
Flg. 1 is a schematic diagram of a narrow slab extrusionmachine of the present invention.
Fig. 2 (A), ~B), (C), (~) & (E) are schematic diagrams
of the narrow slab extrusion machlne. Showing the principles of
the cutting and core-plugging operations.
Fig. 3 (A) & (B) are schematic diagrams of the extrusion
machine for prestressed concrete large size cored slabs (wide
slab), Fig. 3 (A) shows the front view and Fig. 3 (~) shows the
side view.
Fig. 4 is a schematic diagram of the placement of
transverse reinforcing steel in the prestressed concrete large
siæe cored sla~s (wide slab).
Fig. 5 is a schematic diagram for supplement feeding of
the intermediate ribs in the prestressed concrete large sized
cored
6a
~27~012
slabs (wide slabs).
Fig.6 (A) & (B) are schematic diagrams of extrusion
machine for prestressed concrete cored wide slabs, showing the
principles of operation of movement of the cutting blade. Fig.6
(A~ shows the state where the cutting blade is being moved forward
by the machine in two steps. Fig.6 (B) is the state where the
cutting blade is being moved Eorward by the complete machine.
It can be seen from Fig. 1 and 2 that the narrow slab
extrusion machine of the present invention is composed of the main
electric motor (23), the transmission mechanism (3), at least one
spiral conveyor (22), the vibratory elements (7,9), position-
restraining device (25), the hpper(5), and characterized in that
the said cutting and core-plugging mechanism (24) can cut the
molded concrete cored slab into sections and with cores on both
ends plugged. The said mechanism is in itse~f composed of the
cutting blade (8), blade cylinder (18), blade vibrator (17),
supplement feed device (10), supplement-feed plate (19), supple-
ment-feed plate cylinder (13), hydraulic pressure station (14) and
the means for movement of the cutting blade. The said cut~ing
blade (8) is rigidly connected with the blade cylinder(18), which
in turn is rigidly connected with the blade vibrator (17) and
these are parallelly arranged on the upper side of the cutting
blade (8). The supplement-feed device (10) is a metallic container
in rectangular shapes and rigidly mounted on one side of the
cutting blade and movable following the up and down movement of
the above mentioned cutting blade(8). The distance between the
lower side of supplement feed device(10) and the blade point is
~7~
equivalent to the thickness of cored products. The supplement-
feed plate(19) is rigidly connected with the supplement feed
plate cylinder(13) and located on one side from the cutting
blade(8), on top of the machine frame(1). The supplement feed
plate cylinder(13) actuates the supplement feed plate(19) to push
conerete to the lower side of the supplement-feed device(10). The
said means for movement of the cutting blade may include the main
electric motor ~23); or it may include the inner wall plate(20),
outer wall plate(21), the cylinder(12) of inner-outer wall plate,
as well as the support cylinder( 11 ); or it may include the inner
slide plate(26), outer slide plate(27j, inner-outer slide plate
cylinder(28) and the support cylinder(11). The transmission mecha-
nism(3) of the present invention of extrusion machine for forming
prestressed concrete cored single slab is of the all slanting gear
multi-level deceleration and multi-axial output type. The hopper
of said extrusion machine is independent of the main machine and
supported by four posts(4) directly in contact with the ground and
is rolled forward by means of rollers. In Fig.1, (15) denotes
supplement-feed hopper(15), (16) denotes supplement-feed
channel(16).
The present invention of an extrusion machine for
forming prestressed concrete cored wide slabs comprises the main
electric motor(52), transmission mechanism(29), muti-piece spiral
conveyor(31), vibratory elements (32.44), position-restraining
device (30) and the hopper (45) (Fig.3). The machine is charac-
terized by having a cutting and core-plugging mechanism (61)
capable of cutting the molded cored slabs into sections with cores
~72 1)12
on hoth ends plugged and the forming of several ribs in the cored
large slabs. The said mechanism (61) comprises the cutting
blade(41), cutting blade cylinder (43), blade vibrator (42),
supplement feed slide plate(51), the supplement feed slide plate
cylinder(39), supplement feed slide plate vibrator (40), supple-
ment feed device(34), supplement feed plate(35), supplement feed
plate cylinder(36), the hydraulic pressure station(37), the means
for movement of the cutting blade and the supplement-feed
hopper(38)~ The said cutting blade (41) is rigidly connected with
the blade cylînder(43), which in turn is rigidly connected with
the blade vibrator(42) and they are paralelly arranged on the
upper side of the cutting blade(41). The said supplement feed
slide plate cylinder(39) and the supplement feed slide plate
vibrator(40) are rigidly connected and mounted on the upper side
of the supplement feed slide plate(51), which is paralelly
arranged with the cutting blade(41). The said supplement feed
device(34) is a metallic container in a rectangular shape rigidly
mounted on the bottom end of one side of the supplement feed slide
plate(51), with the bottom end of the supplement feed device(34)
being flushed with the bottom end of the supplement feed slide
plate(51). With the wide slab extrusion machine, other forms of
arrangement of the supplement feed device is also feasible. For
example, by omitting the supplement feed slide plate and with the
supplement feed device mounted on the cutting blade as before, but
having two positions designed (an upper and a lower one) for its
fixing, the said device during the core-plugging in places of the
transverse reinforcing steel, can be mounted to and fixed at the
7~ Z
lower side of the cutting blade by the operation of the cylinder,
and again raised to the original position ~or plugging of cores on
the two ends. The said supplement feed plate(35) and supplement
feed plate cylinder(36) are rigidly connected and located at one
side from the supplement feed slide plate(51) on top of the
machine frame(49), with the supplement feed plate cylinder(36)
actuating the supplement Eeed plate(35) to push concrete to the
lower side of the supplement feed device(34). In the mechanism of
the said wide slab extrusion machine means for movement of the
cutting blade have the main electric motor(52); or inner wall
plate(58), outer wall plate(57), inner-outer wall plate
cylinder(64) and the support cylinder(53); or the inner slide
plate(54), outer slide plate(55), inner-outer slide plate
cylinder(56) and the support cylinder(53). (fig. 6(A), 6(B)).
The transm~ssion mechanism of the said wide slab extrusion
machine(29) is of the all slanting gear multi-level deceleration
and multi-axial output type; the said hopper(45) is independent of
the main machine but with four posts(46) as support through
rollers directly placed on the guide rails(48), and the machine
and hopper will be moved forward by rollers rolling along the
guide rail. Rollers(68) are also installed at the bottom of the
machine to enable it to roll on quide rails(48). In the present
invention of extrusion machine for forming narrow or wide cored
slabs of prestressed concrete, the said machines have the length
measuring sensor(2), or the length measuring sensor(47) and the
use of micro-computer(6) or the micro-computer(59) for control of
the operation process.
-- 10 --
~7Z~2
Shown in fig. 1 and fig. 2(A), (B), (C), (D) & (E) are
description of the preEerred embodiments of an extrusion machine
for making prestressed concrete cored single slabs (narrow slab).
In the narrow slab extrusion machine, the production
begins with the main electric motor(23) driving the input axial
gear to rotate, and through multi-deceleration, input is distri-
buted by the distribution gear into multi-axial output, with the
output axial actuating the spiral conveyor(22) to rotate and
deliver the aggregates to the rear part. As the concrete aggre-
gates are being delivered to the rear part and got into the bottompart of the main vibrator(7), the main vibrator(7) is started, and
through the vibration of which the aggregates are plasticized by
the addition of pressure from the spiral surface reduction in
space volume of the rear forming cavity(67), denseness of the
aggregates will be gradually attained. The force of reaction of
aggregates will push the machine forward along an aligned direc-
tion(because of restraint of position-restraining device(25), the
machine will not run beyond the reinforcing steel). If the aggre-
gates are not well compacted, insufficient force of reaction will
result to deter the machine from moving further forward, thus
fundamentally assures the quality of slabs to be produced.
Because of independent installation of the hopper(5) from the main
machine, a substantial portion of vibration force of the main
vibrator(7) will not be transmited to the aggregates in the
hopper, no agglomeration of the aggregates will appear, a state of
looseness can be maintained so as to guarantee the free flow of
the aggregates with no obstacle into the spiral conveyor(22) and
- 11 -
the assurance of continuity of the production. Subsequently, due
to the continuous moving forward of the machine, it enables the
fabricated slabs to remain on the ground as production proceeds.
By using the cutting and core-plugging mechanism(24) of this
present invention, slabs may be produced in conformance with the
size and specification required with cores on both ends plugged
and having the required length of spare swing-back steel pro-
vided.
The process of operation for narrow slab extrusion
machine is as follows: The cutting blade(8) being driven by the
blade cylinder(18) is dropped to the lowest point, and by starting
the main motor(23) to actuate the spiral conveyor(22) to rotate,
concrete mix will be pressed under the spiral surface, and by
vibration of main vibrator(7) making it fully compacted with
cores formed. Due to the existence of a certain distance (to be
determined in accordance with related stipulations) between the
cutting blade(8) and the end of core-forming cylindrical body of
the conveyor, when the concrete is being continuously delivered
by the conveyor's spiral surface and pressed to the rear, the
cutting blade will delay part of the mix which is gradually com-
pacted under the vibration of the secondary vibrator(9) and become
solid and thus the formation of plugging at one end (see fig
2(A)). When the secondary vibrator(9) ceases to vibrate, the
cutting blade(8) will be raised to the highest point with the main
vibrator(7) continuing to vibrate and the conveyor(22) continuing
to rotate, the machine will move forward; and with the formed
slabs remaining on the ground, the fabrication of a substantial
- 12 -
length of a slab is completed (see fig. 2 (B)).
Length measuring sensor(2) determines the required
length by the pulse counter (each pulse being O.S mm. long).
According to the pulse counts, the micro-computer(6) signals
commands to the main electric motor(23) and the main vibrator(7)
for ultimate cessation. Supplement feed plate cylinder(13)
actuates the supplement feed plast(19) to push concrete mix to the
bottom part of the supplement feed device(10), while the cutting
blade cylinder(18) will push the cutting blade(8) and the supple-
ment feed device(10) downward and press the feed supplemented intothe cores of slab-end, simultaneously start the blade vibrator(17)
mounted on the cutting blade and have the said feed compacted by
vibration, thus accomplishing the plugging of the other end of the
slab. meanwhile, the cutting blade(8) have had the slab cut,
which is to be followed by the next step of moving the cutting
blade forward for a certain distance to remove a certain portion
of concrete to have been poured, exposing the required length of
reinforcing steel so as to realize the aim of separating the whole
into two single slabs (see fig. 2(C), top diagram). From the
diagram, it can be seen that the moving of cutting blade(8) from
point "a" to point "b" completes the separation of 2 single
slabs.
The mechanism for movement of cutting blade comprises
the following three types of system:
(I) The main motor driven system. When the cutting
blade(8) is lowered and the formed slab has been cut with cores
plugged, start the main electric motor(23), simultaneously start
~Z72~
the main and secondary vibrators, during the time the reaction
exerted by concrete aggregates will force the complete machin to
move forward, thus carrying the cutting blade(8) to move forward
likewise. The cutting blade(8) will push concrete aggregates in
front of it to move forward a certain distance, forming a space
interval between two single slabs. In the process of moving
forward the cutting blade(8), the conveyor will incessantly
deliver concrete aggregates to the rear part to fill up with
compactness the cored parts between the conveyor end and the
cutting blade, acquiring the aim of core-plugging of the front end
of another slab. With the cored space of this section densely
filled, the compacted concrete will pose increasingly greater
detering force to the cutting blade, so that the main electric
motor will stop to operate when the rear part of the machin is
lifted a few millimeters up. Next, stop the secondary vibrator,
lift the cutting blade(8) and then restart the main electric motor
for producing a second slab. The advantages of this system to
move cutting blade forwards are that no additional new equipment
is needed and the ease in operation; while its disadvantages are
the difficulties of controlling the distance of horizontal move-
ment of the cutting blade as well as the limitation of moving
distance other than the maximum permissibility.
(II) The two-step cylinder driven system. At the lower
part of the cutting and core-plugging mechanism(24), a means for
movement of the cutting blade is provided, comprising the inner
wall plate(20), and outer wall plate(21), the inner-outer wall
plate cylinder(12) and the support cylinder(11), (see fig. 2(C)).
- 14 -
~272~L~
The inner wall plate(20) is rigidly cannected with the piston
rod(62) of the inner-outer wall plate cylinder(12) and the cutting
and core-plugging mechanism(24), while the outer wall plate(21) is
rigidly connected with the cylinder t~be of the inner-outer wall
plate cylinder(l2) and the front part of the machine, meaning as
the whole machine with the exception of cutting and core-plugging
mechanism and the support cylinder(11) fixed on the outer wall
plate(21). After the completion of core-plugging of the rear end
of a single slab the cutting blade(8) is lowered into contact with
the ground, with the cutting blade as fulcrum and by starting the
inner-outer wall palte cylinder, without moving the inner wall
plate for the time being, the cylinder will actuate the outer wall
plate and the front part of the machine to move forward a certain
distance from "a" to "b" as shown in fig. 2(C), the length of
which will be determined by the space interval required between
the single slabs. When by slightly raising the cutting blade to
contact no more with the ground, and lowering the support
cylinder(11) as shown in fig. 2(C) by the dotted lines and with
the support cylinder as fulcrum, by starting the inner-outer wall
plate cylinder(12) without moving the outer wall plate for the
time being, the cylinder piston rod(62) will actuate the entire
cutting and core-plugging mechanism to move forward, during which
moving process the cutting blade will push aside a portion of
concrete been formed in the slab, thus resulting in the space
interval between two single slabs. Again, by raising the piston
rod of support cylinder( 11 ), and starting the main electric
motor(23) and the secondary vibrator(9), there will be resulted
~27Z~ Z
the fabrication of the front end of another slab. This system has
the advantage of precise control over the required length of space
interval.
(III) ~he single-step cylinder driven system. A means
for movement of the cutting blade are required in this system,
comprising the inner slide plate(26), outer slide plate(27),
inner-outer slide plate cylinder(28), and the support cylinder
(11). The inner-outer slide plates are intergeared and will move
in relation with each other, as shown in fig. 2(E). In the case-
example of 2(E) the inner slide plate(26) is rigidly connectedwith cylinder tube of inner outer slide plate cylinder(28) and the
machine frame~1), the outer slide plate(27) is rigidly connected
with the piston rod(63) of the inner-outer slide plate
cylinder(28), and the support cylinder~11) is fixed on the outer
slide plate(27). After the completion of the cutting and core-
plugging of the rear end of a slab, by starting the inner-outer
slide plate cylinder(28), the piston rod(63) will push the outer
slide plate and the suport cylinder(11) to move a certain distance
forward. Then, by lowering the support cylinder(11) to contact
ground for establishing the fixed point, and actuating the inner-
outer slide plate cylinder(28) the cylinder tube will arise the
inner slide plate (26) and the complete machine (also the cutting
blade) to move a distance forward, from "c" to "d", as shown in
fig. 2(E), to achieve the goal of dividing the slab into sections.
This system of movement of cutting blade, besides being able to
precisely control the length of space interval, has also the
feature of the absence of relative movemnt in the forming cavity
- 16 -
~2~2~
that avoids the overflow of concrete mixture.
The present invention of _rrow slab extrusion machine
has the following advantages:
(1) The cutting method employed being high in
efficiency (each interval requiring only 30 seconds), low in cost
(equivalent to only one tenth of other methods), capable of deter-
mining the size of spared swing-back steel at ends according to
requirements, and being in conformance with requirements of
seismic resistance; (2) both ends of slab being plugged to become
solid with much greater compressive strength than required, thus
overcoming the defficiencies of current core-plugging practices
which do not meet the stipulated requirements; (3) shape of two
ends of slabs being able to satisfy various requirements by
forming into plane or mechanical-like parts with keyed slots; and
(4) the high accuracy in all geometric dimensions, overcoming the
disadvantage of old cutting methods that are hardly possible to
meet code requirements.
Figures 3(A), 3(B), 4, 5, &(A) & (B) show a description
of the preferred embodyment of wide slab extrusion machin. The
machine consists of at least two transmission mechanisms(29)
paralelly arranged, having multi-axial output, the axials of which
will actuate the spiral conveyors to rotate and push the aggre-
gates to the rear part, where the transverse reinforcing steel(50)
been prefixed at specified positions. After the completion of
core-plugging at the end of a slab, the cutting blade(41) being
raised, the machine will move forward along an aligned direction
of the longitudinal reinforcing steel(66). When the machine
- 17 -
l~ZI~;2
reaches the position of the intermediate transverse steel, a jack
rodt33) will lift the transverse steel pre-arranged in touch with
the around to a specified position (see fig. 4), which process
should be done soon after spiral of the conveyor has passed over
the transverse steel, as it is the moment when the pressing force
is the greatest, and with the addition of vibration from vibrator,
concrete around the transverse steel is of the utmost denseness.
As the machine continues to proceed forward and the supplement
feed device (34) is just on the top of transverse steel (fig.
3(A)), the supplement feed device(34) will function to fill
compactly the section of core (about 10 cm wide), as seen in
fig. 5, during which time the cutting blade is not allowed to drop
down. With the supplement devices arranaged on top of all cores,
each core will be filled to compactness, forming a strip of ribs.
Other cores overlaid with transverse steel are likewise filled
compactly as above-mentioned, forming muti-strip of ribs. When
the end cores of a slab are plugged, the cutting blade will have
to be moved a distance forward, to form space interval between two
single slabs. Like the narrow slab extrusion machine, wide slab
machines have also three similar types of system for movement of
the cutting blade, including: (I) The main motor driven system,
in which, by starting the main motor(52), the complete machine
will move forward; and when the cutting blade is moving with the
machine, it pushes concrete forward for a certain distance, as can
be seen from the top diagram of fig. 6(A). The principle and
process of operation are the same as that of narrow slab machine.
(II) The two-step cylinder driven system.
- 18 -
~27~
This has a means for movement of the cutting blade at
the lower part of cutting and core-plugging mechanism, comprising
the inner wall plate(58), outer wall plate(57), inner-outer wall
plate cylinder(64) and the support cylinder(53), as can be seen in
fig. 6(A). The structure and operation process of the said means
are essentially the same as those for the narrow slab machine.
The inner wall plate(58) is connected with the piston rod(65) of
the inner-outer wall plate cylinder(64) and the cutting and core-
plugging mechanism(61), the outer wall plate(57) is connected with
the cylinder tube of the inner-outer wall plate cylinder(64) and
the front part of the said extrusion machine, and the support
cy]inder(53) i5 fixed on the outer wall plate(57), when the
cutting & core-plugging of the end of a single slab are completed,
with the cutting blade(41) as fulcrum, to enable the inner-outer
wall plate cylinder(64) to work, and without moving the inner wall
plate for the time being, the cylinder tube will drive the outer
wall plate and the front part of machine to move froward for a
certain distance, from "a" to "b" (see top diagram of fig. 6(A).
By lowering the support cylinder(53), with which as fulcurm,
starting the inner-outer wall plate cylinder(64), then the piston
rod(h5) of the cylinder will drive the complete cutting & core-
plugging mechanism(61) to move forward, with the cutting blade
following as well. The difference of means for movement of
cutting blade in wide slab extrusion machine from that narrow slab
extrusion machine is that the pushing force of the cylinder
employed being much greater.
(III) The single-step cylinder driven system
- 19 -
~Z7Zi~)12
This has the means for movement of cutting blade,
comprising the inner slide plate(54), outer slide plate(55),
inner-outer slide plate cylinder(56) and the support cylinder(53)
as shown in fig. 6(B). the structure and operation process are
essentially the same as those for the narrow slab, but with the
pushing force of the cylinder much greater than that for the
narrow slab. The inner slide plate(54) is rigidly connected with
the cylinder tube of inner-outer slide plate cylinder~56) and the
machine frame(49), while the outer slide plate(55) is connected
with the piston rod(60) of inner-outer slide plate cylinder(56),
and the support cylinder(53) fixed on the outer slide plate(55).
When the cutting and core-plugging at the end of a large size slab
are completed, the inner-outer slide plate cylinder(56) will oper-
ate the piston rod(60) to push the outer slide plate(55) and
suport cylinder(53) to move a certain distance forward. Then by
lowering the suport cylinder(56) and with which such fulcrum, the
cylinder tube of the inner-outer slide plate cylinder will enhance
to move the inner slide plate(54) and the complete machine
(carrying the cutting blade as well) for a certain distance
forward. Seen from the lower diagram of fig. 6A, the no.(66)
denotes the longitudinal reinforcing steel.
Large size cored slabs produced by the wide slab extru-
sion machine have weights less than solid slabs by 40%, with good
performances in sound and thermal insulation, as well as an
increased production efficiency of over 10 times than that of
solid slabs. It is conceivable that with the promotion and appli-
cation of the said wide slab machine, there will certainly be
- 20 -
,~2
possible to Eurther reduce the cost of building construction,
shorten the construction period and upgrade the construction qual-
ity of building structures, thus bringing in new vitality to the
further accelerated development of construction industry.
- 21 -
