Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an apparatus for clamping metallic
moulds wh;ch enables facilitating the work of attaching or detaching
metallic moulds.
When plastlcs are moulded by injection mouldlng, compression
moulding or transfer moulding, metallic moulds which shape the products to
be moulded are attached to the moulding machine. Hence special apparatuses
are used to clamp four points - upper and lower ends of right and left
side of the attachment plate of the metallic mould.
The conventional apparatus for clamping metallic moulds comprises
a clamp bar, a space block and a bolt. Because two metallic moulds are
clamped face-to-face on a fixed die-plate and a movable die-plate of the
moulding machine, at the upper and lower ends of both sides, eight devices
are used to clamp the metallic mould onto the moulding machine.
The attachment plates are pressed toward the die-plate of the
moulding machine by the clamp bars. The clamp bar is a long block having
a slit therein. The bolt, penetrating into the slit, is screwed Oll the
die-plate. The space block is inserted between the clamp bar and the die-
plate to keep the clamp bar parallel with the die-plate.
However, these devices for clamping metallic moulds are incon-
venient, because they take a long operation time to attach or detach themetal]ic moulds.
First, because of safety factors, the bolts must be completely
taken off in order to detach the clamp bars from the die-plate. In this
case, the operation of turning the bolt must be done for the full length
of the screw coupling. However, it is a very tedious work to revolve the
bolt many turns.
Next9 according to the different thickness of the attachment
plate, different space blocks with a thickness suitable to the attachment
plate must be applied~ Therefore, many sizes of space blocks must be
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prepared at all times
Thirdly, even if the bolt is difficult to turn, the operator must
turn a spanner engaged with the bolt with one hand, while holding the clamp
bar and the space block wi`th hIs other hand. If the clamp bar and the
ipace block were left untouched, t~e space block may fall on the foot of
the operator at the moment of loosening of the bolt.
Hence the conventional clamping apparatus takes a long time to
attach or detach to the die-plate of the moulding machine, and the opera-
tion is not always done wi-th safety.
To resolve the difficulties another clamping apparatus was
devised, which has a clamp bar coupled with the function of a space block
in a body. In this apparatus the clamp bar has an adjusting bolt at its
rear end. A separated press plate, which is fixed on the die~plate by a
bolt, presses the clamp bar upon the attachment plate.
If the thickness of the attachment plates varies, this clamping
apparatus enable~ the clamping of any metallic mould by adjusting the
projection length of the adjusting bolt. Therefore it needs no prepara-
tion of various kinds of space blocks. This is very advantageous.
However, another difficulty occurred due to the continuous
adjustability.
In fact, the thickness of the attachment plate of the metallic
mould is standardized in many countries. For exa~ple, a few kinds of the
attach~ent plates9 whose thickness varies stepwise by 5 mm units, are
manufactured in some countries~
When th;s clamping apparatus i5 used, the oper~tor must measure
the projection length of the adjust;ng bolt with his eye. Partly because
the projection length of the ~olt changes continuously and partly because
eye measurements are not accurate9 the opeator wastes much time and effort
in fixing the clamp bar to be parallel with the surface of the die-plate.
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Furtherrnore there appears to be another disadvantage. The -top
end of the projection of the adjusting bolt hinders the revolution of the
spanner engaged with the bolt especiall~ in the case of the use of thin
attachment plates of metallic ~oulds.
An object of a broad aspect of this invention is to provide con-
venient apparatus for clamping metallic moulds which can be easily attached
or detached safely in a short time
By one broad aspect of this invention, clamping apparatus is
provided for use with a die~plate, comprisingi a clamp member having a
stepped clamping surface, thereby providing alternative clamping levels;
a spacing block adjacent the clamp member having at least two operative
fixed positions with respect to the clamp member thereby providing at
least two different spacing heights between the clamp mernber and the die-
plate, the upper surface of the spacing block supporting the clamp member;
and a coupling member connectinq the spacing block with the clamp member
and allowing movement of the spacing block between the two operative
positions.
By a variant thereof the clamp member has two stepped surfaces
comprising: a top stepped surface and a bot-tom stepped surface; and where-
in eight different space heights are provided in conjunction with the
spacing block.
By another aspect of this invention~ clamping apparatus is pro-
vided, comprising a clamp member having branched clamp arms and lower
step parts formed at the front ends of the cl~np arms; a space block with
an oblong side surface; a coupling plate connecting the space block loose-
ly with the rear-end of the clamp member to permit rotation of the space
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block; a pressing plate for pressing the clamp member, the pressing plat.e
having protrusions holding the clarnp arms therebetween; and a fixing bolt
for connecting the pressing plate to a support surface~
By one variant thereof, the pressing plate is asymmetric with re-
gard to the fixing bolt and preferably such pressing plate has two side:
protrusions of different thicknesses.
By another variant thereo:E, step parts are shaped on both sur
faces of each of the branched clamp arms; the Step parts on each arm on one
surface having a first depth and the step parts on the other surface having
a second depth, the first and second depths being different from one
another.
By yet another variant thereof the clamp member is comprised of
two parallel clamp arms and a coupli.ng block welded at the rear ends of the
clamp arms.
By still another variant thereof, at least one spring is located
between the space block and the rear end of the clamp member for pulling
the space block toward the clamp member by an elastic force.
By a variation thereof, a rivet penetrating the rear end of the
clamp member and screws fixed on the side surface of the space block hold
the coupling plates and the springs to permit revolutions of the space
block.
By another variation thereof, screws fixed on the rear side sur-
face of the clamp member and screws fixed on the side surface of the space
block hold the coupling plate and the spring to permit revolutions of the
space b].ock.
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In the accompanying drawings,
Figure 1 is a plan view of an apparatus for clamping the metallic
mould of an embodiment of an aspect of this invention;
Figure 2 is an elevational view of the apparatus;
Figure 3 is a sectional view taken along the line III - III of
Figure 2;
F;gure 4 is`a perspective view showing the attaching operation
of the apparatus onto a metallic mould;
. Figure 5 is a schematic view of a clamping state in which the
apparatus clamps the attachment plate with the largest thickness;
Figure 6 is a schematic view of a clamping state in which the
apparatus clamps an attachment plate with the second largest thickness;
Figure 7 is a schematic view of a clamping state in which the
apparatus clamps an attachment plate with the third largest thickness;
Figure 8 is a schematic vie.w of a clamping state in which the
apparatus clamps an attachment plate with the fourth largest thickness;
Figure 9 is a schematic view of a clamping state in which the
apparatus clamps an attachment plate with the fifth largest thicknéss;
Figure 10 is a schematic front view oE an embodiment of another
aspect of this invention;
Figure 11 is a plan view of an apparatus for clamping metallic
moulds of a Ihird embodiment of an aspect of this invention;
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Figure 12 is a front view of the third embodiment;
Figure 13 is a sectional view taken along the line XIII - XIII
of Figure 1~;
Figure 14 is a perspective view of the separated apparatus
shown in Figures 12 and 13;
Figure 15 is a plan vlew showing the clamp;ng state of a
metallic mould of one conventional clamping apparatus;
Figure 16 is a perspective ~iew of a clamp bar of one conven-
tional apparatus; and
Figure 17 is a perspective view of a clamping apparatus of
another prior art device.
Turning firstly to the prior art, Figure 15 shows, in plan view,
a conventional clamping apparatus. The conventional apparatus for clamp-
ing metallic moulds comprises a clamp bar A, a space block B and a bolt C.
Because two metallic moulds are clamped face-to-face on a fixed die-plate
D and a movable die-plate D of the moulding machine, at upper and lower
ends of both sides, eight devices are used to clamp the metallic moulds
onto the moulding machine,
The attachment plates F are pressed toward the die-plate D of
the moulding machine by the clamp bars A. Figure 16 shows a perspective
view of the clamp bar A, which is a long block having a slit G. The bolt
C, penetrating into the slit G, is screwed on the die-plate D. The space
block B is inserted between the clamp bar A and the die-plate D to keep
the clamp bar A parallel with the die-plate D.
However, these devices for clamping metallic moulds are incon-
venient because they take a long operation time to attach or detach the
metallic moulds.
First, because of safety factors, the bolts C must be completely
taken off in order to detach the clamp bars A from the die-pla~e D. In
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this case the operation of turning the bo]t must be done for the full
length of the screw coupling~ Hence it is a very tedious work to revolve
the bolt many turns.
Next, according to the different thickness of the attachment
plate F, different space blocks B with a thickness suitable to the attach-
ment plate F must be applied. T~erefore many sizes of space blocks must
be prepared at all times
Thirdly, even if the bolt C is difficult to turn, the operator
must turn a spanner engaged with the bolt C wi~h one hand, holding the
clamp bar A and the space block B with his other hand. If the clamp bar
and the space block were left untouched, the space block B may fall on
the foot of the operator at the moment of loosening of the bolt.
Hence the conventional clamping apparatus takes a ]ong time to
attach or detach to the die-plate of the moulding machine, and the opera-
tion is not always done in safety.
To resolve the difficult;es, another clamping appartus was
devised, which has a clamp bar coupled with the function of space block in
a body. Figure 17 is a perspective view of the clamping apparatus as
another prior art~ In this apparatus~ the clamp bar H has an adjusting
bolt I at its rear end. A separated press plate J, which is fixed on the
die-plate by a bolt K, presses the clamp bar H upon the attachment plate.
If the thickness of the attachment plate varies, this clamping
apparatus enables the clamping of any metallic mould by adjusting the pro-
jection length of the adjusting bolt I. Therefore it needs no preparation
of various kinds of space blocks. This is very advantageous.
However another difficulty occurred due to the continuous
adjustability.
In fact the thickness of the attachment plate of the metallic
mould is standardized ;n many countr;es. For example9 a few kinds of the
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attachment plates, whose thickness varies stepwise by 5 mm units, are
manufactured in some countries.
When the clamping apparatus shown in Figure 17 is used, the
operator must measure the projection length of the adjusting bolt I with
his eye. Partly because the projection length of the bolt I changes con-
tinuously and partly because eye measurements are not accurate, the
operator wastes much time and effort to fix the clamp bar H to be parallel
with the surface of the die-plate.
Furthermore there appears to be another disadvantage. The top
end of the projection of tne adjusting bolt I hinders the revolution of
the spanner engaged with the bolt K, especially in the case of thin
attachment plate of metall;c mould
Now referring to Figure 1, one embodiment of an apparatus 1 for
clamping metallic moulds compr;ses a clamp member 2 to clamp an attachment
plate of a metallic mould upon a die-plate of a mould machine 9 a space
block 3 to keep the clamp member 2 parallel with the die-plate, a pressing
plate 4 to press the clamp member 2 on the attachment plate, and a fixing
bolt 5 to fix the pressing plate 4 on the die-plate.
The clamp member 2 and the space block 3 are connected with a
coupling plate 6 having a long hole and a spring 7.
The clamp member 2 consists of two parallel front clamp arms 8,
and a coupling block 9 which is welded at the rear ends 10 of the front
clamp arms 8 to couple the two arms in a body. Therefore a front aperture
11 opens between the front clamp arms 8 for passing the fixing bolt 5
therein. Furthermore lower step parts 12 are formed at the front ends of
the clamp arms 8.
As shown in Figure 4, the clamp member 2 is easily attached to
or detached from the press-ing plate 4.
The coupling plates 6 are loosely suspended on both sides of the
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clamp member 2 by a rivet 13 penetrating through the cl~mp member 2 and
wea~ly pushed on Both sides of the space block 3 by screws 1~ an~ 15 fixed
on the sides of the space block 3~
The spring 7, whlch is spanned between the rivet 13 and the
screws 14 and 15, pulls the space block 3 toward the clamp member 2 by
elastic force. The spring 7 facilitates the operation of attaching or
detaching the clamp member 2, because the space block 3 is always in facé-
to-face contact with the cl~mp member 2 by the elastic force of the spring
7.
The side surface of the space block 3 is not a square, but an
oblong. The lengths of the ~o s;des of the surface are not equal. Here
P denotes the longer side and Q denotes the shorter side of the oblong.
In Pigure 2 the longer side P contacts with the clamp member 2.
If the operator rotates tbe space block 3 by a right angle from the state,
the shorter side Q comes în contact with the clamp mem~er 2.
Then R denotes the depth of the lower step part 12. When the
opera~or turns the clamp me~ber 2 to be in a reverse configuration from
the state shown in Figure 2, he can clamp another attachment plate thicker
than the former one by R
Because the attachment plate F is clamped by the front ends oE
the clamp arms 8 3 the height X of the bottom surface of the front ends
thereof from the base plane, in which the bottom surface of the space
block 3 is included, must be equal to the thickness of the attachment
plate F to hold the clamping member 2 parallel with the die-plate of the
moulding machine.
Because of the loose coupling between the clamp member 2 and
the space block 3 by the coupling plate 6 and the spring 7 3 the clamp
member 2 can be reversed and the space block 3 can be revolved. Then the
height X of the front end of t~e clamp member is equal to the following
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five values:
(1~ X ~ R ~ P (Figure 5)
(2) X = R + ~ (Figure 6)
(3) X = P (Figure 7)
(4) X = Q (Figure 8)
(5) X = R (Figure 9)
The figures from F;gure 5 to Figure 9 show the five different
states corresponding to the equations from Eq. ~1) to Eq. (5).
In Figure 5, an attachment plate with the largest thickness is
clamped by the lo~er step part 12 of the clamp arms, wlth which the shorter
side of the space ~lock contacts. Then the height X is equal to the sum
of the longer side P of the space block and the depth R of the step part 12.
In the second state shown in Figure 6~ the longer side of the
space block contacts with the clamp arms. The height X is equal to the
sum of the shorter side Q and the depth R.
In the third state shown in Figure 7, the clamp member is
reversed, and the flat surface 19 of the clamping member touches an attach-
ment plate, whose thickness îs equal to the longer side P of the space
- block.
In Figure 8, the space block is revolved by a right angle from
the state shown in Figure 7. An att~h~nt plate with a thickness Q can
be clamped in this state.
In the fifth state shown in Figure 9, the space block is
removed to the rear end of the clamp member. The height X is equal to the
depth R of the step part~
Hence this apparatus is available for Eive kinds of metallic
moulds with different thickness in common.
For example if the values of P, Q and R are a~sumed that
P - 25 mm, Q = 20 mm and R = 10 mm~ this apparatus is fully useful to all
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attac~ent plates with a thickness of 35 mm, 30 mm, 25 1~9 20 mm, or 10 mm.
Figure 10 shows an apparatus for clamping metallic moulds as an
embodiment of a second aspect of the invention schematically. This embo-
diment has another lower step part 12' on the reverse surface of step part
12. This embodiment can clamp attachment plates with three different
surfaces - the flat surface 19, the lower step part 12 and 12'. ~ denotes
the depth of the new step part'.
Then the height X for clamping attachment plate can freely be
changed to be a desired value selected among the following eight values:
(1) X = S + P
(2) X - R + P
(3) X = S + Q
(4~ X = R + Q
(5) X = P
(6) X = Q
(7) X = S
(8) X = R
In practice the pressing plates 4 are ~itted on the die-plates
of the mould ~hin~ by the fixing bolts 5. After loosening the fixing
bolt;5 slightly~ the operator attaches or detaches the clamp member 2
together with the space block 3. The orientations of the attaching or the
detaching operation are horizontal. Therefore i~ is better to shape the
pressing plate 4 asymmetric. In this embodiment side protrusions 17 and
18 of the pressing plate 4 have different thickness. Because the weights
of the side protrusions 17 and 18 are different, the pressing plate 4 is
stably suspended along a vert;cal l;ne by the action of gravity. This is
a stable state of the pressing plate 4 as shown in Figure 4. It is very
convenient for the operator to attach the clamp member into the pressing
plate 4 by sliding it along a horizontal direction.
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In the aforementioned embodiment, the cl,~lp member 2 is manufac-
t~lred from three metal pieces by welding them in a body. Because these
metal pieces are easily made by s~ear;ng a simple square bar, the material
cost is low in these embodiments.
Of course, the clamp member can be made in a body from the
beginning without welding
Figures ll to 14 show a third embodiment of an aspect of this
invention.
In this embodiment, the clamp member is a single metal piece
with branched forefronts. Other features of this embodiment are substan-
tially common with the former one. This clamp member ? has a Front aper-
ture 11 between the branched clamp arms for passing the fixing bolt 5
therein. Coupling plates 6 and springs 7 loosely connect the clamp member
2 and a space block 3
In this apparatus 20, screws 21, 22, 23 and 2~ are used to sus-
pend the coupling plate 6. The screws may, of course, be replaced by
rivets.
Furthermore the spring 7 can be omitted, because the necessary
condition concerning the connection between the clamp member 2 and the
space block 3 is that the space block car.not be separated from the clamp
mem~er but can be revolved around the clamp member and around itself.
The invention it broad aspects thereof provides the following
effects:
(1) The operator need not take off the fixing bolt 5 completely
but can leave it remain on the die-plate of the moulding machine. Then he
can tighten or relax the clamp member by a few ~urns of the fixing bolt 5.
Because the operation of turning the bolt, which takes much time gener-
ally, is greatly reduced, the operator is able to attach or detach the
metallic mould onto the moulding machine in a short time.
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The space block 3, which is coupled with the clc~mp member 2, does
not fall in relaxing of the fixing bolt 5. This fact assures ~he sarety
of the operation.
Thus the main effect of this invention is ease and safety in
the operation.
(2) In many cases the thickness of the attachment plates a~e
standardized to be ;dentified ~ith some discrete values. For example, the
thickness of the attachment plates is either one of 20 mm, 25 mm, 30 mm
and so on. Because the apparatus of aspects of this invention combines
the clamp member with lower step parts with the space block with an oblong
side surface, it adapts the dIscrete differences of the thickness of
attachment plates at its convenience. Because the variation of the clamp
height X is not continuous but discrete, this invention enables -the
operator to avoid the inaccuracy owing to eye measurements.
(3) Furthermore if the pressing plate 4 is asymmetric, it is
stable at rest along a vertical line by the action of gravity. It will
facilitate the operation for attaching the clamp member, because the
operator need not arrange the orientation of the pressing plate 4 before
attaching.
