Not applicable.
1. Field of the Invention
This invention relates to an apparatus for feeding flat products such as newspaper inserts, sheets or signatures into pockets or other areas of a machine, and more particularly to an improved feeder having accelerator and decelerator devices to improve feeding speed and efficiency.
2. Description of the Related Art
Typically, in a newspaper insert machine such as one shown in U.S. Pat. No. 4,723,770 or in U.S. Pat. No. 5,823,320, paper inserts or other flat products are placed in a stationary stack, and are fed by an automatic feeder one at a time from the bottom of the stack down into pockets moving beneath the feeder. Such feeders typically employ a rotating drum within the feeder to pull sheets from the bottom of the stack and feed them into the pockets.
There are several challenges that must be overcome in this arrangement to achieve very high speeds together 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. Next, the product, which in the case of thin, highly flexible paper inserts, must be transferred while keeping the product as straight as possible to maximize transfer speeds while minimizing crumpling or warping. 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, or to “bounce” out of the pocket after transfer.
Thus, there is a need for an accelerating device to grab and “shoot” the product down into the pocket or other parts of the machine as fast as possible. At the same time, there is also a need for a decelerating device adjacent to the accelerating device to slow down the product just before the product(s leading edge is about to reach the bottom of the pocket, to prevent the product from bouncing out of the pocket or crumpling within the pocket.
The present invention satisfies the above-mentioned needs, among others. An improved product feeder is disclosed that automatically feeds flat products at very high speeds to other parts of a machine, such as to open moving pockets in a newspaper insert machine. Feeding speeds of tens of thousands of products per hour are achieved by this invention.
In one embodiment, newspaper inserts are fed one at a time from the bottom of a vertical stack to down near a rotating drum. Various types of drums may be employed. For example, the drum may have grippers that periodically reach out and grab the leading edge of an insert, pull it around the periphery of the drum, and shoot it down into pockets on a moving conveyor. In another embodiment, a segmented pusher disk is used to push the leading edge of an insert down to a pair of rollers.
In both embodiments, the area of feeding and grabbing is important. In the first embodiment, a mechanical gripper grabs the sheets. In the second embodiment, a segmented wheel grabs the sheets. In both embodiments, two roller assemblies are employed. One roller assembly acts as an accelerator device, and the other roller assembly acts as a decelerator device. Specifically, a pair of high-speed nip rollers is mounted adjacent to a pair of lower-speed nip rollers. Each roller in each assembly is arranged to press against an opposite roller, such that each pair of rollers is able to grab and pull a sheet or other flat product passing between the roller pairs. Both roller assemblies are positioned adjacent to a rotating drum or pusher disk of the feeder, near an area where the product is fed from a stack to other parts of a machine. The combination of these roller assemblies first speeds up the motion of the product as it comes off the drum or pusher disk, accelerating it to a linear speed faster than the circumferential speed of the drum or pusher disk, and faster than a speed that would be achieved by free-fall in gravity alone, and then quickly slows the product down before the leading edge of the product hits the bottom of the receiving pocket.
More specifically, in one embodiment, the invention comprises a feeder comprising:
drum means for feeding a flat product from a first area to a second area;
accelerator means adjacent to the drum means to accelerate the product as it comes off the drum means; and
decelerator means adjacent to the accelerator means to decelerate the product before the product is fed to a third area.
In another embodiment, the invention comprises an apparatus for feeding flat paper products, comprising:
a feeder having a rotating gripper drum for pulling the leading edge of a flat paper product from the bottom of a stack;
a pair of accelerator rollers biased against each other and adjacent to the drum for accelerating the product as the product comes off the drum; and
a pair of decelerator rollers biased against each other, one of which is segmented, adjacent to the accelerator rollers for decelerating the product before the product is released into a pocket.
In another embodiment, the invention comprises an apparatus for feeding flat paper products, comprising:
a feeder having a rotating segmented pusher disk for pushing the leading edge of a flat paper product down from the bottom of a stack;
a pair of accelerator rollers biased against each other, one of which is segmented, adjacent to the pusher disk for accelerating the product away from the pusher disk; and
a pair of decelerator rollers biased against each other, one of which is segmented, adjacent to the accelerator rollers for decelerating the product before the product is released into a pocket.
In another embodiment, the invention comprises an accelerator/decelerator apparatus, comprising:
a pair of accelerator rollers biased against each other, for accelerating a flat product from one area to a second area, and
a pair of decelerator rollers biased against each other, one of which is segmented, adjacent to the accelerator rollers for decelerating the product before the product is transported to a third area.
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 some embodiments of the present invention that are particularly useful for feeding flat paper, plastic or other products, such as inserts, sheets, cards, signatures, disks, mail, film packages, etc., from a stationary location to a moving location. In one embodiment, the product is grabbed from a stationary stack, pulled around the periphery of a rotating drum within a product feeder, 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 beneath the product feeder. The invention is not, however, limited to such uses 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 exterior appearance of one embodiment of the invention is shown in
Another embodiment of the invention is shown in
Within the feeder 1 is a rotating gripper drum 20 having a shaft 22 driven by an electric motor (not shown). In the embodiment illustrated in
Drum 20 also has areas of varying friction around its periphery. In this embodiment, as shown in
In a feature of the invention, two assemblies of rotating rollers are mounted near the drum 20. The first assembly comprises one or more accelerator rollers 50 mounted opposite to one or more accelerator backup rollers 55. Rollers 50 and 55 are arranged to press against each other tightly, with a biasing device such as a spring (not shown), and are configured such that a paper insert or other flat product may pass between, and be tightly grabbed and pulled by, the rollers. Thus, the two rollers 50, 55 form a nip, and are sometimes referred to herein as high-speed nip rollers. Roller 50 is motor-driven, but roller 55 is not. However, both rollers may be driven if desired.
In another feature of the invention, both high speed nip rollers 50, 55 are mounted adjacent to, but do not rotate synchronously with, the rotating drum 20. Instead, they rotate faster. The purpose of the faster rotation is to pull the product away from the drum faster than the circumference of the drum is rotating. That way, the product will be shot down faster into the pocket than the drum could otherwise push it or drop it. The axis of rotation of each roller 50, 55, is parallel to the shaft 22 (axis of rotation) of the drum 20. It can, however, be seen in
One or more carry-down rollers 80 are also provided above the high-speed nip rollers 50, 55. Preferably, rollers 80 have a high-friction surface, and are biased against the periphery of the drum, to form a nip that assists in pulling inserts 14 around the periphery of the drum 20. In this embodiment, rollers 80 are idler rollers, i.e., not actively driven by a motor. They may, however, be driven if desired.
Mounted adjacent to, and preferably below, the high-speed nip rollers 50, 55 are one or more smooth decelerator rollers 60, as shown in
The operation of the embodiment of
Looking now at
In
In
In
In
The timing of the operations described in
In a feature of the invention, the feeding of the next insert in the stack 10 is started before the first insert has been completely fed into a pocket. As seen in
Another embodiment of the present invention is illustrated in
In this arrangement, one or more reciprocating suckers 220 are mounted underneath tray 12. These are configured to periodically pull down, using vacuum, the leading edges of inserts or other products stacked in the tray. A pusher blade or other device (not shown) may also be employed in addition to or instead of the suckers, to push the leading edge of the product downward. In addition, pulses of air are periodically blown from a nozzle 320 between the lowermost sheet and the second lowermost sheet in the tray to separate the sheets. Air is pulsed in timed relationship with the movement of the suckers 220.
In a feature of the invention, as shown in
Biased against the protruding portions of disk 200 is a pusher disk backup roller 210. This may either be an idler roller or it may be driven. Preferably, roller 210 is made of urethane or other compliant material. A pinch point is created between the surface 201 of disk 200 and roller 210. As the lowermost sheet enters this pinch point, the sheet is pulled rapidly downward away from the tray.
In another feature of the invention, mounted adjacent to the pusher disk 200 is a segmented speedup roller 250 driven by motor 270. Roller 250 has a high-friction surface 252 around most of its periphery, and a low-friction surface 254 around a small portion of its periphery. Surface 254 is preferably recessed slightly within roller 250. Biased against roller 250 is a speedup roller backup roller 260, which is preferably an idler roller. Rollers 250 and 260 are configured such that a paper insert or other flat product may pass between the rollers.
Mounted adjacent to, and preferably below, rollers 250 and 260 are one or more smooth decelerator rollers 65, as shown in
In another feature of the invention, one or more sheet steel guides 300 are mounted adjacent to roller 65 and extend part way below it. These guides serve to stiffen the product as it is fed down into the pocket, so as to minimize the tendency of the product to crumple as it hits the bottom of the pocket at high speed. The guides also help to slow down the product by friction.
In operation, after a sucker 220 has pulled down the leading edge of the lower-most insert in the tray 12, and as the segmented pusher disk 200 rotates clockwise, a protruding portion 202 of the disk engages the upper surface of the leading edge and begins to push it downward. As the disk 200 continues to rotate, the insert is caught temporarily in a depression 204 in the disk, and the insert is bent further downward until if reaches the backup roller 210. At this point, the insert is grabbed by the nip formed by the disk-roller pair. The frictional contact pulls the insert further down from the stack
When the leading edge of the insert reaches segmented speedup roller 250, it is grabbed by the nip formed by the pair of rollers 250, 260 when their high-friction surfaces are in contact. The insert is then accelerated downward. The purpose of the low-friction segment of 250 is to allow the roller to slide past the insert as the insert is first being fed down from the pusher disk 200. This prevents tearing of the insert since the peripheral speed of the pusher disk 200 is lower than the peripheral speed of the speedup roller 250.
The insert needs to be slowed down before it is released into a pocket 100. Since the periphery of roller 65 is moving slower than the insert, insert 14 is immediately decelerated as the leading edge of the insert reaches the nip formed by roller 60 pressing against the high-friction surface segment 70 of roller 65. The purpose of the segment is for accurate timing of the deceleration. Specifically, deceleration is delayed until the last possible moment, so as to maintain maximum feeding speed consistent with proper paper handling. In this way, the insert 14 drops into the pocket 100 without crumpling or bouncing, yet at high speed.
A more detailed, step-by-step description of the operation of a preferred embodiment of the invention of
Next, the product stack is “jogged” by a vibrating panel to ensure the folded edges are uniform and in the same plane. Air is also introduced by the panel to inflate and separate the product.
Next, an array of reciprocating suction cups (such as 5 cups moving together) bends the “nose” of the lowermost product down. The suction cups do not move the product's surface that is in contact with the feed tray.
Next, separator fingers rotate to create a pinch point between the urethane surface of the separator finger and the opposing compliant rollers. This captures the full product thickness and creates linear motion in the product relative to the feed tray.
Next, while the product is being removed from under the pile, a blast of air separates the moving product from the stationary product immediately above. Preferably, air only pulses when the product is experiencing linear motion.
Next, a pinch point or nip is created between a high speed wheel 250 and a compliant backup wheel 260. This set of wheels doubles the product speed. The large diameter wheel 250 has a step in the outer diameter to allow the product to be engaged by the full product thickness.
Next, rollers 65, which preferably are of fixed diameter, rotate at one-half the linear speed of the rollers in the prior high speed section. The urethane surface of the wheel slows the product down for proper exit from the feeder.
Next, sheet steel guides 300 form the product for stiffness upon exiting the feeder and continue to decelerate the product due to friction of the paper sliding along the surface of the guides.
Finally, the product completely exits from the bottom of the feeder and is inserted into a moving pocket 100.
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.
This application is entitled to the benefit of U.S. Provisional Patent Application Ser. No. 60/618,811, filed Oct. 14, 2004. Such application is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
60618811 | Oct 2004 | US |