Control for injection molding

• US 3,881,091 A
• Filed: 08/31/1973
• Issued: 04/29/1975
• Est. Priority Date: 08/04/1971
• Status: Expired due to Term

• Current Assignee: Power Solutions Incorporated (Technipower Systems, Inc.)
• Original Assignee: Charles Leon Day
• Inventors: Day, Charles Leon
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Bell, Fred E.
• Application Number:
  US05/393,567
• Time in Patent Office: 606 Days
• Field of Search: 219/483,486,494,497,499,501,503,506,489
• US Class Current: 219/489
• CPC Class Codes: B29C 45/76 Measuring, controlling or regulating measuring in general G01; controlling or regulating in general G05
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 5/2573 with control circuit

Abstract

A control for heating currents in multiple cavity molds in injection molding machines. The principal features include separate modular power controls each having variable resistor means with an accessible dial for controlling current through a triac and means for avoiding high value transient voltages. Other features include a switch to provide instantaneous maximum current, means for switching from 220 to 110 volts, and lamp means for indicating operating condition.

Claims

1. A control device of high precision for use in controlling high current loads, as for example, heating currents for multiple cavity molds in injection molding machines, comprising in a compact enclosure a separate power control for each load, each such control comprising:

a. a solid state, bidirectional conducting device (827) for controlling current flow in two directions through a load;

b. phase-shifting capacitor means (823) connected in parallel to said conducting device (827);

c. variable resistor means (804) connected in parallel to said conducting device (827) and in series with said capacitor means (823);

d. diode means (818) connected across said conducting device (827) for passing high value transient voltages to reciprocal voltages, and e. switch means (1803) to short out said variable resistor means (804) and provide maximum current through said conducting device (827).

2. The control of claim 1 which includes diode (815,816) and resistor means (822) to prevent a snap-on effect.

3. The control of claim 1 which includes switch means (802) and diode means (817) for limiting trigger voltage to one-half the applied voltage.

4. The control of claim 1 which includes current limiting resistor means (830) and indicator lamp means (805) in series across conducting device (827), so that lamp means (805) shows the operating condition.

5. The control device of claim 1 wherein the enclosure has recesses and modules detachably mounted in said recesses;

each said module containing components (a), (b) and (d) of claim 1 of a separate control, components (c) and (e) being separately mounted in the enclosure.

6. The control device of claim 5 wherein each control has switch means (802) and diode means (817) for limiting trigger voltage to one-half applied voltage.

7. The control device of claim 5 wherein each control has diode (815,816) and resistor means (822) located in a said module to prevent a snap-on effect.

8. The control device of claim 5 wherein each control has limiting resistor means (830) and indicator lamp means (805) located in said enclosure in series across said conducting device (827) so that lamp means (805) glows brilliantly if conducting device (827) is triggered late but is turned off if conducting device (827) is triggered early thus being a visual indicator of the operating condition.

9. The control device of claim 5 wherein said module has a hollow metal body (62) with fins (63,64).

10. The control device of claim 5 wherein said module has a hollow metal body (62) with fins and a conducting surface (62a).

11. The control deVice of claim 5 wherein said module is detachably mounted by pin (60) and socket means.

12. A power control module adapted for use with a variable resistor to produce a variable high current in a high current load, as for example, a heating circuit for a mold used in injection molding, comprising a hollow, metal body (62) having detachable mounting means (60) and containing encased within said body:

a. a solid state, bidirectional conducting device (827) for controlling current flow in two directions through a load;

b. phase-shifting capacitor means (823) connected in parallel to said conducting device (827); and

c. diode means (181) connected across said conducting device (827) for passing high value transient voltages to reciprocal voltages;

said components being sealed from the atmosphere with a potting compound.

13. The module of claim 12 wherein the body (62) has fins (63, 64).

14. The module of claim 12 wherein the body (62) has a flat conducting portion (629).