Bibliographic Details
| Title: |
Velocity profile for clamp lockover |
| Patent Number: |
5,180,530 |
| Publication Date: |
January 19, 1993 |
| Appl. No: |
07/705,831 |
| Application Filed: |
May 28, 1991 |
| Abstract: |
A close clamp cycle for an injection molding machine in which a toggle locking motion is executed using a plurality of velocities to permit faster clamp operation while maintaining control of the clamp to bring it quietly to its final position without damage to the machine. |
| Inventors: |
Cropper, Dennis J. (Georgetown, OH); O'Bryan, James E. (Cincinnati, OH); Waits, Susan (Hillsboro, OH) |
| Assignees: |
Cincinnati Milacron, Inc. (Cincinnati, OH) |
| Claim: |
What is claimed is |
| Claim: |
1. A method effected prior to injecting molten plastic material into a mold for controlling motion of a toggle mechanism coupled to a first mold element on a molding machine, said toggle mechanism being operative to move from an open position at which the first mold element is separated from a second mold element to a locked position at which the mold elements are in contact, the method comprising the steps of |
| Claim: |
a. moving the toggle mechanism from the open position at a rapid velocity; |
| Claim: |
b. decelerating the toggle mechanism to a second velocity less than the rapid velocity in response to the first mold element being a predetermined distance from contact with the second mold element; |
| Claim: |
c. accelerating the toggle mechanism to a third velocity greater than the second velocity in response to the first mold element being in contact with the second mold element; and |
| Claim: |
d. decelerating the toggle mechanism to a velocity approximately equal to the second velocity in response to the toggle mechanism being a predetermined distance from the locked position. |
| Claim: |
2. A method effected prior to injecting molten plastic material into a mold for controlling motion of a toggle mechanism on an injection molding machine, said toggle mechanism being mechanically coupled to and moving a first mold element into a contacting relationship with a second mold element, the method comprising the steps of |
| Claim: |
a. producing a rapid velocity signal and a slowdown position signal; |
| Claim: |
b. operating the toggle mechanism to move the first mold element toward the second mold element at a rapid velocity in response to the rapid velocity signal; |
| Claim: |
c. producing a feedback signal representing toggle mechanism position; |
| Claim: |
d. detecting a toggle mechanism position being equal to a position defined by the slowdown position signal; |
| Claim: |
e. operating the toggle mechanism to move the first mold element toward the second mold element at a mold touch velocity; |
| Claim: |
f. detecting contact between the mold elements; |
| Claim: |
g. producing a high lockover velocity signal and a lockover position signal; |
| Claim: |
h. operating the toggle mechanism in response to the high lockover velocity signal; |
| Claim: |
i. detecting a toggle mechanism position being equal to a position defined by the lockover position signal; |
| Claim: |
j. producing a low lockover velocity signal and a final lockover position signal; |
| Claim: |
k. operating the toggle mechanism in response to the low lockover velocity signal; |
| Claim: |
l. detecting a toggle mechanism position being equal to a position defined by the final lockover position signal; and |
| Claim: |
m. terminating motion of the toggle mechanism. |
| Claim: |
3. A method effected prior to injecting molten plastic material into a mold for minimizing the time required to move a toggle mechanism through a total displacement from an initial position at which mold elements are in initial contact to a final position at which the toggle mechanism is in a final locked configuration, said total displacement being comprised of a first displacement required to decelerate the toggle mechanism from a low lockover velocity to a zero velocity without causing damage to the machine and a second displacement representing the difference between the total and first displacements, the method comprising the steps of |
| Claim: |
a. producing a high lockover velocity signal representing a velocity to which the toggle mechanism may be accelerated during motion through the first displacement; |
| Claim: |
b. moving the toggle mechanism at the high lockover velocity through the second displacement; |
| Claim: |
c. producing a low lockover velocity signal representing a velocity from which the toggle mechanism may be decelerated to a zero velocity during travel through the first displacement without causing damage to the machine; and |
| Claim: |
d. moving the toggle mechanism at the low lockover velocity through the first displacement. |
| Claim: |
4. The method of claim 3 wherein after the step of moving the toggle mechanism at the high lockover velocity, the method comprises the step of decelerating the toggle mechanism from high lockover velocity to the low lockover velocity. |
| Claim: |
5. A method effected prior to injecting molten plastic material into a mold for moving a toggle mechanism of a clamp on an injection molding machine from a mold touch position at which mold elements mounted on the clamp are in initial contact to a locked position at which the toggle mechanism is in a locked position, the method comprising the steps of |
| Claim: |
a. producing a rapid lockover velocity signal and lockover slowdown position signal; |
| Claim: |
b. moving the toggle mechanism at a velocity represented by the rapid lockover velocity signal; |
| Claim: |
c. producing a feedback signal representing a position of the toggle mechanism; |
| Claim: |
d. detecting a toggle mechanism position being approximately equal to a position represented by the lockover slowdown position signal; |
| Claim: |
e. producing a final lockover velocity signal and a final lockover position signal; |
| Claim: |
f. moving the toggle mechanism at a velocity represented by the final lockover velocity signal; and |
| Claim: |
g. terminating motion of the toggle mechanism in response to the position of the toggle mechanism being approximately equal to the position defined by the final lockover position signal. |
| Current U.S. Class: |
264/405; 2643/281; 425/150; 425/590; 425/593 |
| Current International Class: |
B29C 4580 |
| Patent References Cited: |
4519763 May 1985 Matsuda et al.
4917840 April 1990 Harada et al. |
| Primary Examiner: |
Heitbrink, Jill L. |
| Attorney, Agent or Firm: |
Wood, Herron & Evans |
| Accession Number: |
edspgr.05180530 |
| Database: |
USPTO Patent Grants |
