Note: Descriptions are shown in the official language in which they were submitted.
CA 02238088 1998-OS-20
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ADJUSTABhE MOLD CLAMPING WEDGES
This invention relates to :injection molding presses,
and i:n particular, clamping or locking wedges that are used
to locate or centre molds or dies in the mold press.
In injection molding, mold presses are used to clamp
various die components together prior and during the
molding process. It is necessary that these die components
1.0 be a=Ligned accurately for the molded components to be
produced with the correct wall thicknesses, etc. As the
mold press closes ar.~d the various die components are
brought together, it is usual for the dies to engage
clamping or locking wedges, or what are sometimes referred
1.5 to as die locks or die wedges, to align or center the dies
properly. These clamping wedges are usually just blocks of
tool steel with oblique wedging surfaces which are engaged
by the die components. The clamping wedges are removable
from the mold press and are usually replaced relatively
20 frequently because they are subject to considerable wear in
view ~of the mass and forces of the components engaging and
the clamping pressures used in injection mold presses.
In an attempt to reduce the frequency of replacement
25 of these clamping wedges, shims are often used to relocate
the oblique wedging surfaces of the clamping wedges and
make up for wear. However, a difficulty with the use of
shims is that it is very time consuming to make the necess-
ary adjustments, and accuracy is also a problem.
It is an object of the present invention to provide a
means for a quick arid accurate adjustment of the mold
clamping wedges, and this is accomplished by providing the
clamping wedges with their own positioning wedges movable
by threaded adjusters to adjust the position of the clamp-
ing oblique wedging surfaces.
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According to the: invention, there is provided an
adjustable mold clamping wedge comprising a main body
portion having an oblique wedging surface adapted to be
engaged by a moving portion of a closing mold. The main
body portion includes at least one slotted mounting hole
for mounting the main body portion in a mold for position
adjustment of the oblique wedging surface. The main body
portion includes a second wedging surface located
transversely of the oblique wedging surface. A positioning
1.0 wedge is located for sliding engagement against the second
wedging surface and has a bearing surface adapted to engage
the mold and support the clamping wedge therein. Also,
threaded adjustment means is mounted between the main body
portion and the wedge for moving the wedge relative theret-
0, thereby adjusting 'the position of the oblique wedging
surface .
Preferred embodiments of the invention will now be
described, by way of example, with reference to the accom
z0 panying drawings, in which:
Figure 1 is a perspective view of a preferred embodi-
ment of a mold clamping wedge according to the present
invention;
~5
Figure 2 is a diagrammatic cross sectional view
showing the clamping wedge in use in a mold press;
Figure 3 is an enlarged cross-sectional view of the
30 area indicated by chain dotted circle 3 in Figure 2;
Figure 4 is an .enlarged cross-sectional view taken
along lines 4-4 of Figure 1;
35 Figure 5 is an enlarged cross-sectional view taken
along lines 5-5 of Figure 1 with the lower wedge components
removed for clarity;
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Figure 6 is an enlarged cross-sectional view taken
along lines 5-5 of Figure 1, but showing only the lower
adjusting wedge;
Figure 7 is a partial elevational view taken in the
direction of arrow 7 o~f Figure 5;
Figure 8 is a top plan view, partly broken away, of
the clamping wedge shown in Figure 1;
Figure 9 is an enlarged cross-sectional view similar
to Figure 3 but showing another embodiment of a clamping
wedge according to the present invention; and
1.5 Figure 10 is a perspective view of the threaded
adjusters or bolts used in the embodiment of Figure 1.
Referring to the drawings, a preferred embodiment of
an adjustable mold clamping wedge is generally indicated in
Figure 1 by reference numeral 10. The use of clamping wedge
10 is indicated diagrammatically in Figure 2, where clamp-
ing wedges 10 are used to position die components in an
injection mold press for producing an article like a cup or
bucket. A female upper mold half 12 has a cavity 14 which
is filled by a plug 16 being part of a lower mold half 18.
Upper and lower mold halves 12, 18 could be the actual mold
press, or they could be the actual dies that are mounted in
a mold press (not shown) . For the purposes of this disc-
losure, upper and lower mold halves 12, 18 could be either
~0 dies or parts of the mold press. In either case, it is
necessary to align the upper and lower mold halves 12, 18,
so that the wall thicknesses of the article being molded
are produced accurately. Clamping wedges 10 provide the
necessary centering or alignment of the mold halves as they
come together prior to the injection or die casting proc-
ess.
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Clamping wedge 10 includes a main body portion 20
having an oblique wedging surface 22 which is adapted to be
engaged by the upper mold portion or half as it moves
downwardly to close t:he mold. Main body portion 20 has
slotted mounting holes 24, and bolts 26 pass therethrough
to mount clamping wedges 10 onto lower mold half 18. As
seen best in Figure S, main body portion 20 has a second
wedging surface 28 located transversely of the oblique
wedging surface 22. A positioning wedge 30 (see Figure 6)
has an upper sliding surface 32 for sliding engagement
against second wedging surface 28. Positioning wedge 30
also :has a lower bearing surface 34 which engages the lower
mold half 18 and supports clamping wedge 10 therein.
Positioning wedge 30 also includes transverse threaded
holes 36, and bolts o:r cap screws 38 ( see Figure 10 ) are
threaded into threaded. holes 36 (see Figures 3 and 9).
As seen best in Figures 5 and 7, main body portion 20
has slotted shoulder openings 40 for accommodating bolts
38. Shoulder openings 40 include slotted holes 42 and
recesses 44 that defirLe shoulders 46. Bolts 38 have heads
48 which bear against shoulders 46, so that as bolts 48 are
turned to be threaded into threaded holes 36, positioning
wedge 30 is pulled inwardly to raise the main or upper body
portion 20 of mounting wedge 10. It will be appreciated
that as bolt 38 is screwed into positioning wedge 30 and
the wedge is moved inwardly, bolt 38 moves downwardly in
slotted hole 42, because main body portion 20 is being
lifted up, and vice versa when bolt 38 is unscrewed from
wedge 30. Coil springs 50 are located in recesses 52 and
urge ~or bias wedges 30 outwardly tending to allow main body
portion 20 to be lowered when bolt 38 is unscrewed from
wedge 30. In this way, when bolts 38 are backed off or
unscrewed, springs 50 .cause the wedges 30 to move outwardly
and main body portion 20 to be lowered.
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As seen best in Figures 4 and 8, wedges 30 include
slotted holes or openings 54 in registration with slotted
holes 24 to accommodate mounting bolts 26 and allow wedges
30 to slide in and out or reciprocate under main body
portion 20.
As seen best in Figure 10, bolts or cap screws 38 have
a distal end 56 formed with a drive slot 58. Drive slots 58
are provided so that bolts 38 can be turned from the front
through holes 36 which then become access openings. Altern-
atively, bolts 38 can be turned by engaging the bolt heads
48 from behind in the usual manner. For this purpose,
access openings 60 (see Figures 3 and 9) can be provided in
lower mold half 18 for' gaining access to bolts 38.
1. 5
It will also be noted that in the embodiment shown in
Figure 9, clamping wedge 10 is located in a slot 62 in
lower mold half 18 ratlZer than being located in a corner as
in Figures 2 and 3. Of course, it will be appreciated that
clamping wedges 10 can be located in any position, horizon-
tal or vertical, as th.e situation requires.
In operation, one or more clamping wedges 10 are
mounted in a mold press in the position shown, for example,
in Figure 2. As oblique wedging surface 22 wears, so that
upper mold half 12 is not being positioned accurately
enough, bolts 38 are simply adjusted moving wedge 30 to
move the wedge main body portions 20 up or down, causing
oblique wedging surfaces 22 to be located again in the
desired position. Since bolts 38 can be accessed easily
either through holes 36 or access openings 60, very little
machine down time is required to adjust clamping wedges 10.
All that is required is that mounting bolts 26 be loosened
while the adjustment i.s being made, and then retightened.
It will be appreciated that the angle of second
wedging surface 28 and sliding surface 32 can be varied to
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give any desired range of adjustment for clamping wedges
10. Also, the thread pitch of bolts 38 can be chosen to
obtain fine or course adjustment for any given amount of
rotation of bolts 38, as will be appreciated by those
skilled in the art.
Having described preferred embodiments, it will be
appreciated that various modifications can be made to the
structures described above. For example, in reference to
Figures 3 and 9, threaded adjusters or bolts 38 have been
shown to be positioned parallel to the wedge bottom or
bearing surface 34. This requires the use of slotted
shoulder openings 40,, because the upper or main body
portion of clamping wedge 10 moves up and down as wedge 30
moves in and out. However, if the threaded adjusters 38 are
located parallel to second wedging surface 28 and sliding
surface 32, then there is no relative vertical movement
between holes 38 and upper or main body portion 20. In this
case, regular circular holes could be used in place of
slotted holes 42. Also, as another embodiment when bolts 38
are located parallel to wedging surface 28, threaded holes
42 could be used in place of slotted holes 42, and bolts 38
could be replaced by threaded rods having a left hand
thread on one end and a right hand thread on the other, and
with these opposite threads, rotation of the threaded
adjuster 38 would cause the wedge to move in opposite
directions depending o:n the direction in which adjusters 38
are rotated.
It will also be appreciated that the slotted shoulder
openings 40 could be i=ormed in wedges 30 and the bolts or
threaded rods threaded into the main body portion 20 of
clamping wedge 10. It will also be appreciated that slotted
shoulder openings 40 could be formed in both the upper or
main :body portion 20 al2d on the opposite side in wedges 30,
and e;eparate threaded adjusters could be used from both
sides to cause wedge 30 to move in and out. In this case,
CA 02238088 1998-OS-20
springs 50 could be eliminated. It will also be appreciated
that 'the wedges 30 cou:Ld be turned around, so that they are
on the inside as viewed in Figure 3. Finally, it will be
appreciated that the clamping wedges 10 can be made any
size desired, with the wedges 30 being sized accordingly,
as well as the number of mounting holes 24 and threaded
adjusters 30.
As will be apparent to those skilled in the art in the
light of the foregoing disclosure, many alterations and
modifications are possible in the practice of this inven
tion without departing from the spirit or scope thereof .
Accordingly, the scope of the invention is to be construed
in accordance with the substance defined by the following
claims.