Supports: racks – Special article – Stacked articles
Reexamination Certificate
2002-03-25
2003-09-16
Krizek, Janice L. (Department: 3652)
Supports: racks
Special article
Stacked articles
C414S795300, C414S923000
Reexamination Certificate
active
06619486
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a self-pivoted flipper/catcher mounted on a guide pin for capturing thermoformed parts blanked from a sheet of thermoformed parts such as individual condiment containers, personal care items, blister packs and the like.
2. Prior Art Statement
In the art of thermoforming small containers, it is usual to vacuum form or blow mold a large sheet containing a plurality of the containers separated by webs. The large sheet is then advanced to a die cutting operation where individual dies are arranged in an array each die having a width and breadth corresponding to the outer dimensions of the lip of the container. The dies preferably have a series of interruptions around the periphery of the lip of each container to retain the containers on the large sheet for advancement into the separator/up-stacker. In the separator/up-stacker, pushers are arranged under an intermediate clamping plate and a catcher plate each plate having a plurality of apertures with close tolerance fit with its corresponding pusher wherein the large sheet is placed in registry with the pushers on the pusher plate, the pushers are then advanced toward the clamping plates thereby severing the individual containers from the sheet. In order to arrange the individual containers into stacks for transport to subsequent filling operations, the individual containers are captured above the catcher plate in a stacking column. Various means of retaining the containers in the stacking column are shown in the prior art references below. The prior art means of retaining generally results in a wide web between each row and column of the individual containers and alongside the perimeter edges of the large sheet thereby reducing the output of containers and creating additional scrap material. Still, problems exist with the upstacking operation. For instance, without guide pins, the stacked parts tend to tilt or stack in an arc. Tilting or arcing can be caused by defects in the webs of some parts, irregular die cut surfaces, lack of proper taper or shallow height. Shallow parts also tend to jump out of the stack when a new part is upstacked under the existing stack. Falling may also be caused by the operator by jostling adjacent stacks when picking up one stack of parts. These problems often result in the stacks falling over causing downtime to retrieve the fallen parts.
It is known to provide a magazine on a testing and stacking machine for carton or can tops wherein the magazine includes a plurality of vertical rods secured in a base. The can tops are tested for the presence of a metallic staple, and if present, are lifted into the magazine by a spring-loaded lifter. The edges of the can tops move a plurality of can top supporting fingers outwardly against a spring force when the can top is lifted toward the magazine. After the can top passes the end of the fingers, the fingers are forced under the can top by the spring force thereby capturing the can top in the magazine. The lifter is returned to its original position for receiving another can top. For instance, see the U.S. Pat. No. 2,361,960, issued on Nov. 7, 1944, to Nicholas Pelosi. The spring loaded fingers would damage light thermoformed parts resulting in considerable waste.
It is also known to provide an accumulator station for receiving filled and sealed ice cream cups wherein pairs of cups are forced upwardly through support gates which are yieldably swingable toward a vertical position. The support gates are biased to assume an obliquely converging relation capable of temporarily supporting the elevated row of cups in underneath engagement therewith. For instance, see the U.S. Pat. No. 3,622,017 issued on Nov. 23, 1971 to Meuller, et al. The support gates are massive and would damage the light thermoformed parts thus resulting in waste.
It is further known to provide a catcher for stacking components die-cut from a continuous web of material wherein the catcher comprises a mounting bracket in the form of a generally U-shaped yoke, a pivot pin and first and second catcher plates attached to the bracket by the pin. The U-shaped yoke carrying the catchers is screwed to the top surface of the stacker board between two adjacent windows with the first catcher plate extending partially over one window and the and second catcher plate extending over the adjacent window. Lifters elevate the die-cut components such that the flanges thereof engage the bottoms of the catcher plates. The plates hinge on the pin and swing upwardly to a generally vertical position beyond the edges of the plates whereafter the lifters are retracted and the catcher plates return by gravity to a generally horizontal position. For instance, see U.S. Pat. No. 5,391,049 issued on Feb. 21, 1995 to William Reschlein. The substantial width of the U-shaped yoke results in a wide web of material between adjacent components thus resulting in wasted material. Furthermore, the catcher plates are unnecessarily thick, wide and of considerable mass for the capture of the extremely light weight thermoformed parts, the considerable mass sometimes contributing to damaged or distorted thermoformed parts. Additionally, in the catcher of Reschlein, a four by four array of apertures would require a total of 40 catchers to provide for catching the upstacked parts thus requiring the precision drilling of 80 holes to mount the yokes carrying the catchers. Placement of the guide pins of this invention at the corners of the apertures would reduce the cost of preparing catcher plate and in larger catcher plates having a greater number of apertures, the improvements recited in the instant application are further multiplied.
Finally, it is known to capture successive individual thermoformed units into a single stack is a yieldable tubular sleeve having longitudinal slits running from a widened upper end to a lower end forming lamella that project into to the path of the articles to be stacked engaging under the rim or lip of the article. For instance, see the U.S. Pat. No. 6,241,457B1 issued on Jun. 5, 2001 to Hüttig, et al. The yieldable tubular sleeves require that the rim or lip of the article have considerable strength to move the lamella. Many thermoformed parts do not have the necessary lip strength and therefore are destroyed.
SUMMARY OF THE INVENTION
The prior art means of retaining a stack of individual containers removed from a large sheet of die-cut thermoformed material generally results in a wide web between each row and column of the individual containers thus reducing the output of containers and creating additional scrap material. Furthermore, the mass of the prior art means of retaining is greater than necessary therefore more costly. Therefore, it is an object of this invention to provide a self-pivoted catcher for the up-stacking of die-cut thermoformed component parts which comprises a low mass loop of material having opposed ends thereofjournaled in a guide pin wherein the guide pin is affixed in a narrow web of a catcher plate between parallel rows of the die-cut parts removed from a larger sheet. The low mass loop is adapted to move upwardly with movement of die-cut component separated from a larger sheet and advanced through catcher plate, the low mass loop adapted to engage the underside of a lip of the die-cut component thereby retaining the die-cut component on an upper side edge of the low mass loop.
It is principal aim of this invention to provide a self-pivoted catcher journaled on a guide pin disposed in a narrow web of a catcher plate between parallel rows of die-cut parts removed from a larger sheet wherein the guide pin has a thickness dimension substantially equal to the width of the narrow web.
An intention of this invention is to provide a self-pivoted catcher journaled on a guide pin disposed in a narrow web of a catcher plate between parallel rows of die-cut parts removed from a larger sheet wherein the guide pin has a cross section chosen from various shapes, such asround, lobed, rectangular, trapezoidal, triang
Krizek Janice L.
Kwon Michael J.
Marsh Richard L.
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