[0001] This invention relates to a machine for producing blocks or elements, which are formed
by compacting in a mould box a particulate semi-dry mix of material from which the
block or element is to be formed.
[0002] Various forms of machines are known in the art for the production of blocks or elements
as aforesaid but in general each known machine incorporates in its design and construction
a feed box which is open top and bottom, and which can be reciprocated in order to
convey material from a storage hopper, situated at the rear of the machine to the
mould box, which is open top and bottom, situated at the front of the machine.
[0003] In the known machines the material is fed to the feed box during the time the feed
box is in the retracted position, from a hopper usually carried by the structure of
the machine and in order to prevent the material falling from the hopper when the
feed box is advanced over the mould box, a valve has to be provided. The valve may
be simple in form but it does represent an additional part of the machine and is subject
to wear.
[0004] Situated beneath the feed box is the feed table over which the material is pushed
by the feed box from the position under the hopper to a position above the mould box.
The mould box has a horizontal top plate to form a continuation of the feed table.
An actuating mechanism is required to effect the necessary movement of the feed box.
This movement causes wear of the feed table and the top plate of the mould box and
the time required to operate the feed box adds substantially to the machine operating
cycle time.
[0005] A further item regarded as essential to the known machines is a tamper plate which
is moved into the mould box, after the feed box has been retracted, to effect compaction
of the material in the mould box, such compaction in a number of forms of machines
being assisted by vibration. The operation of the tamper plate, from its position
sufficiently above the mould to allow the lateral movement of the feed box, to its
lowered position onto the material in the mould box also adds substantially to the
machine operating cycle time.
[0006] The object of the present invention is to provide a machine of the kind specified
in a simple and convenient form.
[0007] According to the invention a machine for producing blocks of elements comprises a
hopper having a depending throat portion, said throat portion or a part carried thereby
being shaped so that in use, it will locate within a mould box supported in use by
the machine, support means for the mould box, means for effecting relative movement
of said support means and a surface serving in use to close the lower end of said
mould box, further means for effecting relative movement of said throat portion and
said surface and means for vibrating the material in the mould box and said throat
portion to achieve compaction of the material, means located on said throat portion
or said part for defining a fracture plane in the compacted material whereby when
said further means is operated the compacted material will fracture generally in said
plane.
[0008] In the accompanying drawings:-
Figure 1 is a diagrammatic perspective view showing the essential components of the
machine,
Figure 2 is a side view of a practical form of the machine, and
Figure 3 is an end view to an enlarged scale of a portion of the mechanism in Figure
2.
[0009] With reference to Figure 1, the machine comprises a hopper generally indicated at
10 having a depending throat portion 11 which is of a size so that it will enter into
the open upper end of the mould box 12. The throat portion is detachably coupled to
the hopper but it can integral therewith. The mould box in the type of machine to
be described is located on a base board 13 and this board serves to support the finished
block or element in this case a building block or element, during the manufacture
and curing of the block or element. The material is a semi-dry mix having say 5% by
weight of water, the other constituents being well known in the art.
[0010] The throat portion in the particular example is provided with a frame 14 which is
detachably secured around the lower portion of the throat portion, this frame sliding
in use with limited clearance in the mould box.
[0011] f A first actuating mechanism not shown is provided to lift the mould box 12 away
from the base board, the amount of movement being greater than the required height
of the compacted block or element. A second actuating mechanism again not shown is
provided to raise at least the throat portion 11 and the frame 14 by a limited distance
as will be explained. In practice the second actuating mechanism will also raise the
hopper 10 and the two mechanisms can derive their lifting effort from a single power
source.
[0012] Forming an important part of the machine are vibrators which vibrate the material
in the mould box and also the throat portion 11. The vibrators may be of any convenient
type and on the example would make contact with the support (not shown) for the base
board. In the type of machine where the compacted block or element is deposited onto
the floor of the production area the vibrators for compacting the material in the
mould box could be attached to the mould box itself.
[0013] Considering now the operation of the machine, from rest; a semi-dry mix of material
from which the block or element is to be formed, is fed into the hopper and with the
mould box resting on the base board the material will fall through the throat portion
and frame into the mould box. The hopper is maintained substantially full of material
so that the loose material fills the mould box and throat portion. The vibrators are
then turned on and the vibration results in compaction of the material in the mould
box together with the material in the throat portion. This compaction is assisted
by the weight of material in the hopper. When the required degree of compaction has
been attained the vibrators are stopped and the first actuating means is operated
to raise the mould box away from the base board. This has the effect of ejecting the
compacted mass of material from the mould box. The mould box is raised away from the
base board until its lower edge lies above the lower edge of the frame 14. Finally
the second actuating means is operated to raise the throat portion 11 and the frame
14, the extent of movement being of a small order for example two or three centimeters.
[0014] The limited movement effected by the second actuating means results in fracture of
the compacted material generally at the lower end of the frame. The block or element
is therefore left on the base board and the compacted material in the throat portion
serves as a plug to prevent the material in the hopper falling through the throat
portion.
[0015] The fracture plane is in part defined by a projection on the inner surface of the
frame or the throat portion if a frame is not fitted, and conveniently may be formed
by a generally horizontal continuous line of weld material or the like. In this manner
the edge of the fracture plane is well defined but random fracture takes place through
the mass of compacted material generally in said plane. As a result the upper surface
of the block or element has a random split appearance such as is obtained when a piece
of stone is split. The fracture plane can be further defined by an element or elements
mounted on or within the frame. The elements may be mounted so that they extend transversely
of the flow of material into the mould box or they may be mounted so that they extend
in line with the flow. In the former case the elements may be in the form of rods
or bars which can be arranged so as to provide on the fractured surface of the block,
a defined pattern. In the latter case the elements which again may be in the form
of rods, are of a length such that the ends terminate in the fracture plane. If the
ends lie in a flat plane then the fracture plane will be substantially flat but will
still have the random split appearance. The fractured surface of the block or element
can be arranged so that it is generally convex or concave, by altering the lengths
of the rods.
[0016] Returning now to the operation of the machine, the base board together with the block
or element is removed, a fresh board placed in position and the mould box lowered
so that it rests on the base board. The next operation is to destroy the plugging
effect of the compacted material in the throat portion. This is achieved by operating
the vibrator mechanism and when the plug has been broken the material forming the
plug drops into the mould box together with fresh material from the hopper. The frame
together with the throat portion and the hopper may be lowered to the product height
before the compaction of the material in the mould box has started. In some circumstances
however it is preferable to delay lowering of the frame until some compaction by vibration
has taken place because the action of lowering the frame ensures that the material
forming the block or element is further compacted. This can be effected by the second
actuating means.
[0017] The height of the compacted block or element depends upon the distance between the
lower edge of the frame 14 and the upper surface of the base board. This distance
is adjustable in the actual machine. A single mould box can therefore be used to construct
a wide range of heights of block the essential requirement being that when the mould
box is in position on the base board the frame must lie within the mould box.
[0018] A number of blocks or elements can be produced at the same time by providing division
walls in the mould box and by providing complementary shaped divisions in the frame
and throat. Moreover, the mould box may be provided with side apertures into which
can be inserted, prior to the filling operation, cores of the appropriate shape. It
will of course be understood that the cores must be withdrawn after the vibrators
have been stopped but before ejection of the compacted block or blocks from the mould
box can take place.
[0019] Alternatively cores may be placed vertically within the throat portion and mould
box which will, by being attached through the hopper opening to linkage connected
to the mould box, raise and lower in unison with the mould box. The cores may be laterally
located by members secured to the frame.
[0020] In some types of machine, the mould box is fixed in the machine but at the same time
is capable of being vibrated for the purpose of compacting the material therein. In
such a machine a support is provided for the base board which closes the lower end
of the mould box. In this case, following compaction of the material, the aforesaid
first actuating mechanism effects movement of the support for the base board in a
downward direction and the second actuating mechanism effects downward movement of
the frame and throat portion through the mould box in unison with the movement of
the base board, to eject the compacted block from the mould box, followed by upward
movement of the second actuating mechanism to achieve fracture.
[0021] In some other types of machine, the hopper, throat portion and attached frame are
fixed in the machine and the mould box and the support for the base board, which closes
the lower end of the mould box, are movable up and down by the aforesaid first and
second actuating mechanisms. In this case following compaction of the material, the
aforesaid first actuating mechanism effects movement of the mould box in an upward
direction to eject the compacted block and the second actuating mechanism effects
downward movement of the support for the base board, to achieve fracture.
[0022] In Figures 2 and 3 of the drawings there is illustrated a practical version of the
machine, Figure 3 also illustrating a mould box for producing a number of blocks.
The machine includes a support structure 15 and in the particular example, a pair
of spaced guide pillars 16, a similar pair of pillars being provided on the opposite
side of the machine. Each pair of pillars mounts two pairs of slides 17, 18. The hopper
10 together with the throat portion 11 and the frame 14 are carried on the upper pair
of slides 17 and the mould box 12 is supported on the lower pair of slides 18. Each
of the guide pillars 16 is provided with an adjustable stop 19 which limits the downward
movement of the slides 17 and therefore fixes the distance between the lower edge
of the frame 14 and the base board 13. The positions of the stops 19 therefore determine
the height of the finished block or element.
[0023] Each slide 18 is connected to a pair of spaced actuating rods 20. The actuating rods
of the machine are interconnected at their upper ends as in known machines to ensure
parallel movement of the slides 18 and are also connected to an hydraulic actuating
mechanism. Each rod 20 is provided with a lower adjustable stop 21 and an upper adjustable
stop 22 located below and above respectively of the respective slide 17. Moreover,
depending from the upper part of the structure 15 of the machine are clamp rods 23
and carried on the slides 17 are clamp mechanisms 24 which can grip the rods 23 respectively
as will be explained.
[0024] The mould box 12 is not rigidly connected to the lower slide 18 since as shown in
Figure 3, the main portion of the lower slide 18 can continue to move downwardly in
spite of the fact that the lower edge of the mould box is resting on the base board.
During such movement springs 25 are compressed. Figure 3 shows a mould box having
division plates 26 whereby a number of blocks or elements can be produced. It will
be noted that the mould box is symmetrical about its attachment lugs 27. The throat
portion 11 is attached to the hopper 10 and includes pairs of division plates 28.
Each pair of plates comprises a pair of spaced plates disposed on opposite sides of
the respective division plate 26 of the mould box and at the lower ends of the division
plates there is provided a detachable frame 14.
[0025] In operation, Figure 2 shows the positions of the various part following compaction
of the material by vibrators 30 operatively connected to the base board, and after
the rods 20 have just started to move upwardly. The clamp mechanisms 24 are in the
gripping position so that the frame and throat portion are held against movement.
As the rods 20 continue to move upwardly the mould box is lifted and the compacted
mass of material is ejected from the mould box. When the lower edge of -the mould
box lies above the lower edge of the frame the stops 21 move into engagement with
the slide 17. At the same time the clamp mechanisms 24 are released and the throat
portion 11 together with the frame 14 is lifted an amount sufficient to cause fracture
of the compacted mass. The completed block is then left on the base board and is removed
along with the base board. A fresh board is then placed in position and the rods 20
lowered. Before the initial downward movement of the rods 20, the clamp is energised
to retain the throat portion and frame 14 in the raised position. The mould box is
lowered onto the new base board and the vibrators turned on. The vibration disintegrates
the "plug" in the throat portion and frame and the material together with fresh material
falls through the frame into the mould box. A few seconds after the vibrators have
been switched on the clamps 24 are released and continued downward movement of the
rods 20 forces the frame 14 downwardly until halted by the action of the stops 19.
During such movement the springs 25 are compressed, and the material beneath the frame
14 is further compressed.
[0026] It will be seen that the machine as described is much simpler in construction, operation
and maintenance as compared with the known forms of machines, because the actuating
mechanism in the known machines, required to move the feed box, together with the
feed box and feed table, are not required. Furthermore, due to the fact that these
parts are not required, the machine as described also has a substantially reduced
operating cycle time.
[0027] Furthermore, as wear of the lower portion of the mould box takes place owing to the
abrasive action of the material, it is possible to turn the mould box over, since
the upper portion of the mould box is protected by the division plates 28 and the
walls of the throat portion 11.
[0028] In the machine as described a single power source provides for movement of the slides
17 which carry the throat portion and the slides 18 which carry the mould box, with
the actuating means for the raising and lowering of the throat portion comprising
the stops 21 and 22 and the rods 20 coupled to the mould box forming the actuating
means for the mould box. In some forms of the machine separate actuating mechanisms
may be provided for the mould box and throat portion respectively.
1. A machine for producing blocks or elements comprising in combination, a hopper
having a depending throat portion, said throat portion or a part carried thereby being
shaped so that in use, it will locate within a mould box supported in use by the machine,
support means for the mould box, means for effecting relative movement of said support
means and a surface serving in use to close the lower end of said mould box, further
means for effecting relative movement of said throat portion and said surface and
means for vibrating the material in the mould box and said throat portion to achieve
compaction of the material, means located on said throat portion or said part for
defining a fracture plane in the compacted material whereby when said further means
is operated the compacted material will fracture generally in said plane.
2. A machine according to Claim 1 including stop means for limiting the extent of
movement of said throat portion towards said surface said stop means being adjustable
whereby differing heights of the block or element can be produced using a single mould
box.
3. A machine according to Claim 1 in which the mould box is constructed so that it
can be inverted following a period of use.
4. A machine according to Claim 2 including a pair of slides coupled to said throat
portion, pillars carrying said slides, said stop means being mounted on said pillars.
5. A machine according to Claim 4 including a clamp mechanism on said slides and clamp
rods secured to a support structure of the machine whereby the throat portion can
be clamped against movement.
6. A machine for producing blocks or elements comprising the combination and arrangement
of parts substantially as hereinbefore described with reference to the accompanying
drawings.