Device for safeguarding an open position of the closing unit of an injection molding machine
View Patent ↗Injection molding machines must be provided with devices which ensure that the mold mounting plates when in open position cannot inadvertently close, wherein the conventional safety devices include a toothed locking bar disposed between two mold mounting plates and are provided with a ratchet mechanism, but which obstructs accessibility in the space between the two mold mounting plates, so that according with the present invention a blocking unit is disposed outside the space between two mold mounting plates for engagement of the drive unit of the closing unit to thereby prevent an inadvertent closure.
1. A safety device for safeguarding a closing unit of an injection molding machine from inadvertently executing a closing movement, said safety device comprising:
a mechanical blocking unit, interacting with a drive unit for opening and closing the closing unit, said blocking unit disposed outside a space between mold mounting plates of the closing unit; and
an activation mechanism automatically operating the blocking unit, when a protective door to the closing unit is opened for securement of the mold mounting plates of the closing unit in an open position.
2. The device of claim 1 , wherein the drive unit is a rotary motor having a drive shaft, said blocking unit mounted to the drive shaft of the rotary motor.
3. The device of claim 1 , wherein the blocking unit includes a ratchet mechanism with a controllable pawl.
4. The device of claim 3 , wherein the drive unit is a rotary motor having a drive shaft, said ratchet mechanism including a ratchet wheel mounted to the drive shaft of the rotary motor.
5. The device of claim 1 , wherein the blocking unit includes a clamping locking mechanism with controllable clamping jaws.
6. The device of claim 5 , wherein the drive unit is a rotary motor having a drive shaft, said locking mechanism including a clamping wheel, which is mounted to the drive shaft of the rotary motor.
7. The device of claim 1 , wherein the blocking unit is a friction brake.
8. The device of claim 7 , wherein the drive unit is a rotary motor having a drive shaft, said friction brake mounted to the dive shaft of the rotary motor.
9. The device of claim 2 , wherein the drive unit is a spindle drive, with the rotary motor representing a drive motor of the spindle drive.
10. The device of claim 2 , wherein the drive unit is a toggle joint drive, with the rotary motor representing a drive motor of the toggle joint drive.
11. The device of claim 1 , wherein the activating mechanism includes a control member, operatively connected to the blocking unit, and a position switch addressing the control member, when the protective door is opened.
12. The device of claim 1 , wherein the activating mechanism includes a control member, operatively connected to the blocking unit, and a control system provided for the injection molding machine and addressing the control member.
13. The device of claim 3 , wherein the protective door is provided with a pawl, for engaging a ratchet, when the protective door is opened to thereby secure the protective door in opened position.