Multi-pivotable mold carrier clamping apparatus

A pair of mating mold halves are mounted between upper and lower clamp plates 25, 22. The lower clamp plate is driven by a hydraulic unit 17 mounted to a base plate 16, which is rotatably disposed on a tiltable table plate 7. The upper clamp plate is journaled between the arms 26, 28 of a yoke pivotally mounted on the base plate and controlled by hydraulic units 29 coupled between the yoke arms and the upper clamp plate. This compact multi-pivotal arrangement affords a large separation stroke between the two clamp plates without, by reason of the lateral pivoting of the yoke and upper clamp plate, requiring any additional overhead or ceiling clearance space.

BACKGROUND OF THE INVENTION 
This invention relates to a multi-pivotable tool carrier or clamp, 
particularly for mounting and manipulating at least two mating injection 
molds or dies for the manufacture of articles from plastics, such as foam 
expanded polyurethane. 
A tool carrier of this general type is marketed by the German company 
Battenfeld Maschinenfabriken GmbH, under the tradename Type WK. In this 
known tool carrier an upper, second clamp plate is pivotably arranged 
opposite a lower, first clamp plate. A hydraulically activated 
piston-cylinder unit implements the pivotal movement; it is hinged at one 
end to a base plate and at the other end to the second clamp plate. With 
this drive unit the second clamp plate can be pivoted approximately 
100.degree. from its position parallel to the first clamp plate to thereby 
open and close the tool carrier and the molds mounted on and between the 
clamp plates. By these measures the mold halves are easily accessible. If 
this tool carrier is used, for example, for expand polyurethane 
manufacturing, then the finished articles can be easily removed from the 
mold. In other words, after the separation and withdrawal of the upper 
half of the mold the articles can easily be removed from the lower half of 
the mold. This advantage is present to an equal degree when the carrier 
serves in holding other tools, for example when the products are formed 
between two mold halves by means other than plastic expansion, such as by 
die casting. 
In this conventional tool carrier the pivotable second clamp plate is 
hinged to two beams which extend up at a right angle from the base plate. 
When the base plate is horizontal these beams thus stand vertical, and the 
opened second clamp plate is connected at the upper ends thereof. This 
conventional tool carrier thus has a significant vertical height when the 
mold halves are separated and opened, relative to the height of the 
carrier when the unit is closed, i.e. when both clamp plates lie parallel 
to each other. This constitutes a distinct disadvantage in that the 
ceiling height of the factory room must be taken into consideration in a 
limiting or restrictive sense, particularly when the pivotable second 
clamp plate has a large area base surface, which is often necessary or at 
least desirable. As a result this conventional tool carrier is only usable 
for relatively small molds in which small articles are formed, whereby no 
large parallel stroke is necessary between the two clamp plates. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide a tool carrier in which the above 
mentioned disadvantages can be avoided; the tool carrier is characterized 
by the second clamp plate being pivotally mounted on a yoke which is 
itself pivotably hinged to the base plate. 
With this arrangement the vertical distance between the pivot axis of the 
second clamp plate and the base plate can be varied by pivoting the yoke. 
This pivot axis lies at the greatest distance above the base plate when 
the yoke projects perpendicularly upward therefrom, whereat the second 
clamp plate is parallel to the first clamp plate beneath it. When the yoke 
is inclined relative to the base plate the vertical distance between the 
pivot axis (hinge point of the second clamp plate on the yoke) and the 
base plate is substantially reduced, although in this position the second 
clamp plate is in its upwardly hinged orientation and the mold is opened. 
The relative increase in height caused by hinging the second clamp plate 
upwardly is thus compensated for by the lowering of its pivot axis, so 
that despite the opening of the mold the total height of the tool carrier 
is not increased. The tool carrier can thus provide a large parallel 
separation between the two clamp plates at a given ceiling height, and 
still enable effective opening and closing movements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The tool carrier has a base frame consisting of elements 1 through 6, which 
may be welded together. A table plate 7 is pivotably mounted about a 
horizontal axis 8 to the base frame, and its movements are controlled by a 
hydraulic piston and cylinder unit 9. The latter is hinged at one end 10 
to the base frame element 6 and at its other end 11 at the plate 7. A 
limiting knee 12 is provided on the plate 7, and abuts a stop 13 rigidly 
affixed to the frame element 1 when the table plate is in a horizontal 
position. The unit 9 can be retracted until the table plate and components 
mounted thereon are rotated through about 90.degree. (not shown), whereat 
the plate is vertically oriented. 
The plate 7 carries a slewing ring 14 which can be rotated about an axis 
15. A base plate 16 having a generally rectangular configuration is 
rotatably mounted in the slewing ring 14. The base plate 16 is part of the 
closing unit of the tool carrier. The cylinder 18 of a hydraulic piston 
and cylinder unit 17 is connected to the base plate 16, and its piston rod 
19 projects through an opening in the base plate. The base plate 16 
carries two pairs of mounting blocks 20 and 21. 
A first, lower clamp plate 22 of the closing unit lies above the base plate 
16, and is supported on the piston rod 19 of the unit 17. The clamp plate 
22 has a square or rectangular configuration, and is vertically movable by 
means of the piston rod 19. Two parallel rods 23 and 24 serve to guide the 
clamp plate 22; they are slidably disposed in bores in the base plate 16 
and are connected at their upper ends to the clamp plate. 
The closing unit, which includes the base plate 16, the drive unit 17 and 
the guide rods 23, 24, further comprises a second, upper clamp plate 25, a 
U-shaped yoke 26, 27 and 28, a pair of hydraulic piston and cylinder drive 
units 29 and a pair of coupler straps 30. Each drive unit 29 is hinged at 
one end 31 to the second clamp plate 25, and at the other end 32 to the 
yoke arms 26, 28. Each coupler strap 30 is hinged at one end 33 to the 
second clamp plate 25, and at the other end 34 to the base plate 16 at a 
mounting block 21. The second clamp plate 25 is pivotable on two trunion 
pins about an axis 35 in the yoke arms. As seen in FIG. 1, the axis/pins 
35 lies between the two axes/pins 31 and 33. The straps 30 constitute 
guide members for the second clamp plate 25. The yoke 26-28 together with 
the drive units 29 and the straps 30 can be pivoted laterally as 
illustrated with broken lines in FIG. 1, whereat the second clamp plate is 
then located in a vertical position 25'. The yoke 26-28 is pivotable in 
the two mounting blocks 20 about an axis 36. 
In an alternate embodiment (not shown) further hydraulic piston and 
cylinder drive units could be provided in place of the straps 30. These 
further drive units could also be hinged at one end to the base plate 16 
and at the other end to the yoke 26-28, and their operation could pivot 
the yoke relative to the base plate. This arrangement would be more costly 
than the illustrated embodiment, however, because control means would have 
to be provided for the further drive unit, while the straps 30 are passive 
and require no control. The control of the further drive unit would also 
have to be precisely coordinated with the control of the drive units 29 to 
maintain a desired path of motion during the rotation of the second clamp 
plate from its parallel position relative to the first clamp plate 22 
shown in FIG. 1 into the position 25'. This is achieved automatically with 
the straps 30. 
The entire closing unit of the tool carrier can be rotated about the axis 
15 either manually or by an electric motor (not shown) driving a pinion 
gear engaging teeth on the slewing ring 14. With the drive unit 9 the 
entire closing unit together with the table plate 7 can be rotated about 
the axis 8. This enables the closed mold to be tilted after or during 
injection, which is sometimes useful in venting trapped gases. The drive 
unit 17 can raise the first clamp plate 22 to a point where a pair of mold 
halves (not shown) are tightly clamped between the two plates 22 and 25 to 
close the unit and enable injection. To open the closing unit the first 
clamp plate 22 is moved downwardly, back toward the base plate 16. To 
facilitate the removal of the molded article from the lower mold half, the 
second clamp plate 25 is then rotated into the position 25' seen in FIG. 1 
by the drive units 29. 
The described tool carrier, despite having a large parallel span or 
separation distance between the two clamp plates 22 and 25, has a lower 
overall height when the mold is opened, i.e. when the second clamp plate 
25 is in its position 25', than when the two clamp plates are closed and 
parallel to each other. This means that in a given room a tool carrier 
with substantial height which is capable of manufacturing tall articles 
can be set up, since opening the second clamp plate does not increase the 
height of the tool carrier. This pivoting of the second clamp plate 25 
into the position 25' can also be an advantage in exchanging one set of 
molds for another, since the new mold can then be easily lowered into 
place on the vertically accessible first clamp plate 22. 
Further, when the upper mold half is attached to the second clamp plate 25, 
it advantageously lies significantly lower when the clamp plate is rotated 
into the position 25' than with the conventional tool carrier of the type 
described earlier. This enables more easy access to the exposed upper mold 
half, for example to remove the manufactured article therefrom or to clean 
or spray it with a release agent.