1. Field of the Invention
This invention relates to an improved apparatus and method for separating flat products such as newspapers and inserts from a stack and feeding them to a drum or other moving machine parts at high speed.
2. Art Relating to the Invention
At present, machines for handling flat products, such as newspaper insert machines, often include one or more automatic feeders for feeding the products from a stationary stack to other moving parts of the machine. One item at a time is separated from the stack, either from the top or the bottom, and transferred to a rotating drum or other moving part by a separator device housed within a product feeder. Typically, one or more product feeders are mounted above a conveyor carrying open moving pockets, and the feeders transfer products from the drum into the pockets. An example of an insert machine is shown in U.S. Pat. No. 4,723,770.
If the flat products are thin or flexible, such as paper sheets or jackets, then several engineering challenges present themselves for proper and efficient machine operation. First, one item at a time must be separated from the stack without separating or damaging the remaining items. Since sheets of paper, for example, tend to stick together when stacked due to friction and air pressure, a means of separating one sheet from the stack sometimes includes a suction device to pull one sheet away while leaving the remaining sheets in place. After separation, the item must be transferred from the stationary stack to other parts of the machine that are moving, such as a rotating drum or a conveyor.
One example of a prior art separator and feeder apparatus is shown in
Beneath the hopper and the sucker bar, there is mounted a rotating drum 3, which carries one or more grippers 7 around its periphery. The grippers open and close at certain, timed positions as the drum rotates (counterclockwise in
In operation, as an open gripper rotates up towards the hopper, sucker bar 6 pivots upward and suction is applied to the sucker 5. The sucker approaches and then makes contact with an edge portion of the lowermost product in the hopper. As used herein, this edge portion, which is the portion closest to the drum, is called the leading edge of the product.
Next, the sucker bar 6 pivots downward, causing sucker 5 to peel the leading edge of the lowermost product away from the leading edge of the next lowermost product in the stack by suction, and to bend the leading edge of the lowermost product downward. This creates a gap between the lowermost product and the next lowermost product. Meanwhile, the gripper 7 continues to rotate toward the stack. When the gripper moves into a position immediately below the bent-down leading edge of the lowermost product, the gripper closes and grabs the leading edge. Suction is then immediately released from the sucker 5, and the gripper then pulls the product down and around a portion of the periphery of the drum 3. Subsequently, the gripper opens and releases the product into a moving pocket 4, which carries the product away for further processing.
While the above-mentioned prior art separator and feeder apparatus accomplishes the task of separating one product from a stack of products and transferring it to a rotating drum, it has certain limitations that limit the speed of operation of the machine. For example, since the sucker bar is positioned underneath the stack in the prior art, in order for the sucker to clear the leading edge of the paper in time, the sucker bar must swing down (counterclockwise in
In addition, in order for the sucker bar 6 to position the leading edge of the product accurately for proper pick-up by the gripper 7, the sucker bar must pivot all the way down, such that the “final,” extended position of sucker 5 is almost touching the rotating drum. In other words, the distance that the sucker must “travel” is the entire distance between the bottom side of the lowermost product in the stack and the uppermost periphery of the drum. Since there are mechanical limits on how quickly the sucker bar can be pivoted back and forth, the necessity for the sucker to make a “full travel” limits the speed at which products can be separated from the stack and transferred to the drum. This full travel requirement also increases the amount of time that suction must be applied to the sucker, and also increases wear and tear on the sucker bar. In addition, this arrangement requires the drum to have a relatively large diameter, placing limits on the rotational speed of the drum. Consequently, the above disadvantages place an upper limit on the speed of the entire machine. It is desirable to overcome these limitations, particularly in machines such as newspaper insert machines, where extremely high speeds are required.
To overcome the limitations of the prior art, an improved product separator and feeder apparatus and method has now been developed which is capable of separating flat products from a stationary stack of flat products, and transferring and feeding each product individually to a drum or other moving parts of a machine, efficiently and at extremely high speeds.
In order to accomplish this, the separator and feeder apparatus of the present invention employs a unique, specially-positioned pivoting and articulating sucker bar, having several degrees of motion, operating in timed relationship with a unique reciprocating and articulating pusher blade, to reduce the travel distance of vacuum suckers and to increase the speed at which products are separated from a stack and transferred to a rotating drum, for subsequent transfer to a moving pocket.
More specifically, one embodiment of the invention comprises an apparatus for separating and feeding flat products from a stack of flat products, comprising:
a pivoting and articulating sucker bar having at least one sucker mounted thereon, the sucker bar arranged to pivot around a cam profile mounted to one side of and above a lowermost product in the stack, the sucker arranged to periodically pivot up, articulate toward and make contact with a leading edge of such lowermost product and then to pivot down, articulate away and pull down and away such edge by suction to create a gap between such lowermost product and a next lowermost product in the stack; and
a reciprocating and articulating pusher blade arranged to push into such gap, and articulate down, in timed relationship with the sucker bar, to further separate such lowermost product from such next lowermost product, and to push down such leading edge to bring such edge to within range of a gripper.
Another embodiment of the invention comprises a method for separating and feeding a flat product from a stack of flat products, comprising the steps of:
pivoting a sucker about a cam profile located to a side of a stack of flat products, and articulating the sucker toward the stack, until the sucker makes contact with the bottom of a lowermost product in the stack;
applying vacuum to the sucker;
pivoting the sucker down, and articulating the sucker away, from the stack, to create a gap between the lowermost product and a next lowermost product in the stack, and to begin to pull down and away a leading edge of the lowermost product;
pushing a blade into the gap to engage the top of a leading edge of the lowermost product;
releasing the vacuum from the sucker; and
articulating the blade downwards so as to push the leading edge of the lowermost product down and away from the stack and to within range of a gripper.
These and other aspects of the present invention may be more fully understood by reference to one or more of the following drawings, in which:
The following description disclosed an embodiment of the present invention that is particularly useful for separating flat paper products, such as newspapers, newspaper inserts and jackets, from the bottom of a stationary stack of flat products, and transferring them at high speeds to a rotating drum of a product feeder, for subsequent delivery to open moving pockets on a linear conveyor of a newspaper insert machine. The invention is not, however, limited to such use and is usable in any environment where separation and transfer of individual flat items from a stack of flat items to another moving machine part is necessary or desirable.
Turning now to the drawings,
Rotatably mounted under the table 14 and preferably within the frame 12 is a drum 15 (
Referring to
Sucker bar 30 is rigid and hollow and is suitable for supplying vacuum and air to the suckers. A flexible hose (not shown) is attached between the sucker bar and a vacuum and air manifold (not shown). Preferably, the suckers are rubber, cup-shaped and suitable for forming a seal between the sucker and a sheet of newspaper or other flat item when vacuum is applied to the sucker and the sucker is brought into contact with the item, preferably from below. The purpose of the suckers is to grab and pull down and away a leading edge of the lowermost sheet in the stack during a separating and feeding operation.
In another feature of the invention, and unlike product separators and feeders in the prior art, the pivot points or areas of sucker bar 30 are not located under the table 14 holding the stack of flat products 80. Instead, the sucker bar is pivotally and articulably mounted within the frame sideways away from the table and the stack. More particularly, in
In yet another feature of the invention, and as best seen in
As best seen in
In another feature of the invention, mounted to frame 12, and as best seen in
Pusher blade 70 is positioned close to sucker bar 30 (
As shown in
In the preferred embodiment, and as best seen in
In operation, as the drum rotates (counterclockwise in
Between positions of approximately 180 degrees and 270 degrees, while the pusher blade is still pushing the lowermost sheet toward the drum, the sucker begins to reverse direction and move toward the stack in preparation for engaging the next lowermost sheet in the stack. This is a significant feature of the invention in that this arrangement and method of operation permits two sheets to be handled at the same time. Specifically, before the pusher blade has finished pushing the lowermost sheet down to within range of the grippers, the suckers are already moving toward the next lowermost sheet, or have already engaged the next lowermost sheet.
In summary, the present invention provides several advantages over the prior art. First, the sucker bar and pusher blade work in coordinated fashion in multiple ways to separate each product from a stack of products. This reduces the stroke distance of the sucker. The short stroke of the cups allows for decreased response time and increased speed. The sucker movement, pusher blade movement, and vacuum and air operations are all carefully timed and coordinated with the movement and operation of the drum and the grippers to facilitate the quick separation and feeding of flat material.
Using the present invention, it has been discovered that the sucker need travel only about ⅓ of the distance between the stack and the drum. Also, the vacuum can be released from the sucker sooner, and thus disengage the sucker from the paper sooner so that the sucker can move out of the way and prepare to engage the next sheet in the stack. And since the pusher blade is to the side of, and hence out of the way of, the suckers, the suckers can start to pivot up toward the next sheet in the stack while the pusher blade is still pushing the first sheet down toward the drum. Consequently, the coordination of the parts of the present invention permits the parts to work together to provide multiple ways to increase the speed of product separation and feeding, and hence to increase the overall speed of the entire machine.
Although only one embodiment of the present invention has been expressly disclosed, it is, nonetheless, to be broadly construed, and not to be limited except by the character of the claims appended hereto.
Reference is made to prior copending U.S. provisional patent application No. 60/557,716, filed Mar. 30, 2004, entitled “Product Separator and Feeder,” by the inventors of the present invention. Such application is incorporated herein by reference. No federally-sponsored research or development was involved with this application.
Number | Name | Date | Kind |
---|---|---|---|
2552869 | Sauerman | May 1951 | A |
2564417 | Baker | Aug 1951 | A |
2918279 | Jackson | Dec 1959 | A |
3371331 | Buckholz | Feb 1968 | A |
3394930 | Guggisberg | Jul 1968 | A |
3586316 | Ehlscheid | Jun 1971 | A |
4470589 | Singer | Sep 1984 | A |
4509736 | Stahl et al. | Apr 1985 | A |
4723770 | Seidel et al. | Feb 1988 | A |
5029834 | Boldrini et al. | Jul 1991 | A |
5586756 | Chang | Dec 1996 | A |
5967508 | Olexy | Oct 1999 | A |
6015145 | Hartel | Jan 2000 | A |
6017030 | Seidel et al. | Jan 2000 | A |
6082724 | Kahlig et al. | Jul 2000 | A |
Number | Date | Country |
---|---|---|
50-44591 | May 1975 | JP |
7206189 | Aug 1995 | JP |
Number | Date | Country | |
---|---|---|---|
20050218580 A1 | Oct 2005 | US |
Number | Date | Country | |
---|---|---|---|
60557716 | Mar 2004 | US |