Patent Application
20080174066
Not applicable.
1. Field of the Invention
This invention relates to an apparatus for feeding flat products such as newspaper inserts, sheets, signatures and the like into pockets or other areas of a machine. More particularly, the invention relates to an improved feeder capable of feeding products of different thicknesses.
2. Description of the Related Art
In the graphic arts and newspaper industries, insert machines are often employed to automatically insert flat printed or other products into newspapers. Examples of some commercially available insert machines are described in U.S. Pat. Nos. 4,723,770; 5,823,320; and 6,907,316.
An insert machine typically has three basic sections that operate together in coordinated fashion. First, a straight-line pocket conveyor is arranged to carry a series of V-shaped or U-shaped pockets along a closed path. The pockets are typically oriented vertically with the open side of the “V” facing up, and they are carried horizontally by the conveyor. An example of one type of pocket is shown as element 300 in FIG. 1 of the above-mentioned '770 patent.
Mounted above the conveyor are one or more automatic feeder devices. See, for example, feeders 200 and 500 shown in FIG. 1 of the '770 patent. Other types of feeders are shown in U.S. Pat. No. 5,823,320 (FIG. 1, element 2), in U.S. Pat. No. 6,907,316 (element 16 of FIGS. 1-3), and in pending U.S. patent application Ser. No. 11/250,721, owned by the assignee of the present invention. Such feeders typically employ one or more rotating disks, rollers or drums within the feeder, together with suction cups and other devices, to pull sheets from the bottom of the stack and feed them down into the pockets.
In a typical operation, one feeder feeds a “jacket” of a newspaper vertically down into the pockets, one jacket per pocket. Next, as the pockets move downstream, they pass under other feeders that feed inserts down into each jacket. Finally, when inserting is complete, a gripper conveyor (such as structure 700 in FIG. 1 of the '770 patent) picks up the completed newspapers from the pockets and carries the products away for further handling.
Several design features need to be employed to achieve very high feeding speeds, consistent with accurate and efficient paper handling. First, the product must be transferred as quickly as possible from a stationary stack to a moving pocket. When the product is being transferred vertically, the force of gravity is used to assist in product transfer. But gravity is not enough. Just letting the product fall into the pocket does not enable transfer speeds at the desired high rate. An additional mechanical pushing or pulling force is also needed. An accelerating device is sometimes used to grab and “shoot” the product down into the pocket or other parts of the machine as fast as possible.
Next, the product, which is usually a thin, flexible paper insert, must be transferred while keeping the product as straight as possible to maximize transfer speeds while minimizing crumpling or warping in the pocket. Then, once the product has been transferred to the pocket or other area, it must not be allowed to “crash” into, crumple or jam inside the pocket.
Prior art feeders having a design similar to the design of the feeders described in the above-mentioned patents and pending application are quite suitable for many applications. For example, many newspaper inserts are extremely thin, having a thickness of perhaps one sheet of newsprint-style paper. These sheets can be effectively and rapidly fed from a stack of sheets into a series of pockets using an arrangement of internal rollers or disks pressing against each other to form one or more “pinch” points that grab the inserts and pass them to the pockets. Since the inserts in a particular feeder during a particular machine “run” are normally of uniform thickness, the feeding rollers can be mounted on fixed axes of rotation. This arrangement simplifies the design, and is often necessary. Because of the thinness of the inserts and the high feeding speeds required, the feeding rollers must press against each other firmly and consistently.
For some applications, however, it is desirable to have the capability to feed relatively thick inserts or other products, such as magazines, computer disks or even paperback books. While some prior art feeders could be manually adjusted to handle products of varying thicknesses, this adjustment process was typically quite time-consuming, particularly if a large number of feeders were being employed. Also, for safety and other reasons, the entire insert machine frequently needed to be shut down while the manual adjustments were being made, which necessarily slowed down the entire inserting process. Thus, a need exists for a feeder that can be quickly adjusted to handle products of different thicknesses. For best results, the adjustment process should be able to be performed automatically or semi-automatically.
The present invention satisfies the above-mentioned needs. An improved feeder device has been designed that can be quickly adjusted to accommodate widely varying thicknesses of newspaper inserts and other products. Certain features of the invention relate to improvements in the feeder described in the above-mentioned pending application Ser. No. 11/250,721, while other features of the invention are completely new. Feeding speeds of tens of thousands of products, of different thicknesses, per hour can be achieved.
In one embodiment of the invention, a row of pivoting sucker cups pulls down the leading edge of the lowermost product in the feeder stack. Then another device momentarily holds down the leading edge while the sucker cups pivot out of the way. Next, a segmented pusher disk pushes the leading edge down to a nip or pinch point formed between two opposing rollers. Next, the product is passed to another nip formed between another set of opposing rollers operating at a higher speed. The high speed rollers accelerate the product down into a pocket passing below. All rollers are spring-loaded and are mounted on axes of rotation that are not fixed. The rollers can pivot toward and away from each other, to allow thicker products to be fed through the machine. The springs pushing on the rollers may be quickly adjusted automatically or semi-automatically to accommodate products of different thicknesses.
More specifically, in one embodiment, the invention comprises a feeder comprising a housing having a tray for receiving flat products in a stationary stack; a first roller mounted within the housing and biased against a first disk; and a second roller mounted within the housing and biased against a second disk; whereby each roller is arranged to rotate about an axis of rotation that is movable either toward or away from the first and second disks respectively, to allow products of different thicknesses to be fed from the stack, between the first roller and first disk, and between the second roller and the second disk.
In another embodiment, the invention comprises an apparatus for feeding flat paper products, comprising a housing having a tray for receiving flat products in a stationary stack; a first rotatable backup roller mounted within the housing and biased against a segmented rotating pusher disk, the first backup roller being arranged to rotate about an axis of rotation that is pivotable either toward or away from the pusher disk; and a second rotatable backup roller mounted within the housing and biased against a second disk, the second backup roller being arranged to rotate about an axis of rotation that is pivotable either toward or away from the second disk; whereby the distance between the first backup roller and the pusher disk, and the distance between the second backup roller and the second disk, may be adjusted to permit products of different thicknesses to be fed from the bottom of the stack and between the first backup roller and the pusher disk, and between the second backup roller and the second disk, respectively.
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 is a description of one embodiment of the present invention that is particularly useful for feeding flat paper, plastic or other products, such as inserts, sheets, cards, signatures, magazines, books, disks, mail, film packages, etch, from a stationary location to a moving location. Varying thicknesses of products can be accommodated. In this embodiment, a sheet or other product is grabbed from the bottom of a stationary stack, pulled through the machine by a series of disks, rollers and other devices, and is then subsequently delivered at high speed to a moving, vertically-oriented pocket open at the top and being carried by a linear conveyor moving horizontally beneath the product feeder. The invention is not, however, limited to such use and is usable in any environment where feeding of a flat product is needed to transfer the product from one location in a machine to another efficiently and at very high speed.
The overall external appearance of one embodiment of the invention is shown in
Looking next at
The operation of a preferred embodiment of the invention will now be described in detail. First, as best seen in
Next, in a feature of the invention, hold-down finger 450 (
In another feature of the invention, one or more rotating, segmented pusher disks 204 are mounted next to hold-down finger 450. Pusher disks 204 are driven by motor 270. As shown in
Leading edge 10a of lowermost sheet 10 is being momentarily held down, vacuum to suckers 220 is turned off. Next, the sharp end of one of pusher disk drive segments 205 enters the triangular gap (not shown) between two sheets 10 and bends lowermost sheet 10 down further. Next, sucker bar 221 pivots to the left to move suckers 220 out of the way and in preparation for engaging next sheet 10 in the stack. Next, curved outer surface 206 of one of pusher disk drive segments 205 engages low-speed backup roller 210. The outer surface of roller 210 is preferably coated with rubber or other high-friction material.
The engagement of disk 204 with roller 210 creates a low-speed, frictional nip or pinch point. As soon as leading edge 10a of sheet 10 has been bent down to this pinch point, disk 204 and roller 210 grab sheet 10 and start to pull it linearly to the left off of tray 12 and down into machine 1. Roller 210 may be set to one, two, three or more pre-set gage positions relative to disk 204.
Mounted next to pusher disks 204 are one or more high-speed disks 250. As shown in
Disk 250 and roller 260 pressing together form a high-speed, frictional nip or pinch point. As sheet 10 advances down through machine 1, leading edge 10a of sheet 10 is grabbed in the high-speed pinch point, and sheet 10 is immediately accelerated to a faster linear speed down through machine 1. At approximately the same time sheet 10 is being accelerated, drive segment 205 of pusher disk 204 has rotated further clockwise and no longer engages low-speed backup roller 210. In other words, the low-speed pinch point has been released. This prevents sheet 10 from being torn apart as sheet 10 moves from the low-speed pinch point to the high-speed pinch point. Also, at approximately the same time, a clutch (not shown) within low-speed backup roller 210 disengages to improve sheet feeding.
Shortly thereafter, as sheet 10 approaches the bottom of feeder 1, it passes over adjustable bowing rod 470 (
A significant feature of the invention is that products of widely varying thicknesses can easily be handled. One way this accomplished is that some of rollers 210, 260 are mounted on pivoting, as opposed to fixed, axes of rotation. For example, as shown in
In addition to pivoting axes of rotation, backup roller 210, 260 are all spring-loaded, This is best seen in
Compensating rollers (not shown) may also be included in feeder 1.
In yet another feature of the invention, feeder 1 can be quickly and easily reconfigured between machine runs to accommodate products 10 of different thicknesses. To maintain appropriate bias in springs 400, 405, as products 10 of different thicknesses are introduced, there is provided main spring adjustment assembly 402 and secondary spring adjustment assembly 407. Assemblies 402, 407 are best seen in
Adjusting spring 400, 405 involves moving spring rod 406,440 either back or forth, to adjust the compression on rollers 210,260. This adjusts the spring bias at the pinch points. In other words, for example, if thick products 10 are to be fed, performance is improved if the spring bias at the pinch point is reduced. Conversely, if very thin products 10 are to be fed, the spring bias should be increased to maintain adequate friction at the pinch points so that products 10 can be fed reliably and quickly through machine 1.
The mechanism for moving spring rod 440 is shown in
The arrangement shown in
Secondary spring adjustment assembly 407 (
In a preferred embodiment, adjustment of feeder 1 is performed semi-automatically by an operator at the start of a “run” of insert machine 1. The operator will note the thickness of products 10 of feeder tray 12, and then engage air to move spring rod 440 either backward or forward by the proper amount. Alternatively, product thickness may be determined automatically by sensor 475 (
Typically, after a machine run, roller adjustment will be reset so as to create a zero gap (not shown) between rollers 210, 260. As insert 10 is being fed, forcing rollers 210, 260 apart, wedge 430, 435 automatically moves to the correct position, as long as brake 520 is off (see
One aspect of feeder 1, is that pulsed air “kit” (not shown) is available for separate purchase by a customer as a stand-alone unit and installed into feeder 1.
Although only a few embodiments of the present invention have been expressly disclosed, the invention is, nonetheless, to be broadly construed, and is not to be limited except by the character of the claims appended hereto.
| Number | Date | Country | |
|---|---|---|---|
| 60881299 | Jan 2007 | US |
