Patent Grant
6978993
The invention disclosed herein relates generally to a feeder for feeding mail related items such as mail insert materials, envelopes or mailpieces and, more specifically, to a retarding element in a friction feeder for preventing multiple feeds.
Friction feeders are known in the art. As the name suggests, a friction feeder relies on the interaction of several components around the exit nip of the feeder that results in the singulation of paper documents in a paper stack. The common components in most friction feeders are the driving mechanism to drive a sheet of paper document out of the exit nip and the retarding element to retain all the other sheets in the stack so as to prevent multiple feeds. To provide the necessary friction for retaining the other sheets in the stack, the surface of the retarding element is usually made of an elastomeric material or a hard, rough coating. Ifkovits, Jr. et al. (U.S. Pat. No. 5,294,102, hereafter referred to as Ifkovits) discloses a friction feeder wherein the surface of the retarding element is coated with tungsten carbide grit. Godlewski (U.S. Pat. No. 4,666,140) discloses a friction feeder wherein the surface of the retarding element is made of an elastomeric-like material. Green (U.S. Pat. No. 5,244,198) discloses a friction feeder wherein the retarding element is a continuous belt made of an elastomeric material mounted on a pair of rollers. A friction feeder can be designed to operate as a top feeder or a bottom feeder. The above-mentioned friction feeders are bottom feeders, wherein the sheets in a generally vertical stack are moved out the stack, one at a time, by a driving mechanism below the stack. A typical friction feeder is shown in
In order for the retarding element 40 to be effective in preventing other bottom sheets from being pulled out by the driving mechanism 30 along with the bottom sheet 10, the retarding element 40 must have a high friction surface 50 which is fixedly mounted on a roller 42. In operation, the high friction surface 50 is stationary relative to the moving sheet 10. The friction between the bottom sheet 10 and the sheet 10′ above is lower than the friction between the retarding surface 50 and a sheet 10′. If the surface 50 of the retarding element 40 is coated with a layer of hard grit, as disclosed in Ifkovits, paper dust will accumulate at the surface section 52 at the feed zone 62 where the sheets in the singulated portion 24 are retained by the retarding element 40 when the bottom sheet 10 is driven out of the exit nip 64. After extensive use, the surface roughness is reduced mainly because of the accumulated paper dust, thereby reducing the effectiveness of the retarding surface 50. If the surface 50 of the retarding element 40 is made of an elastomeric material, as disclosed in Green and Godlewski, the contact between the sheets and the retarding surface 50 at the feed zone 62 will wear out the contact surface section 52, changing the retard characteristics of the elastomeric surface.
In order to provide an unworn portion of the retarding surface to the exit nip, Green uses a locking mechanism to keep the retarding surface stationary in operation. When it is necessary to rotate the retarding surface to provide an unworn portion at the exit nip, the operator loosens the locking mechanism and manually repositions the retarding surface. This manual method of furnishing an unworn portion of the retarding surface is inconsistent and inconvenient.
Thus, it is advantageous and desirable to provide a method and device for rotating the retarding surface in a simple and consistent fashion.
The present invention provides a method and device for facilitating the replacement of a worn out frictional surface by a fresh one in a friction feeder. This objective can be achieved by mounting a frictional surface on a roller, which is prevented from rotating about a shaft by a polygonal locking member. The locking member is slideably mounted on the same shaft. When the locking member is located at a locked position, it is prevented from being rotated by a blocking surface. But when the locking member is located at an unlocked position, it is allowed to rotate, causing the frictional surface to turn.
Thus, according to the first aspect of the present invention, there is provided a device for use in conjunction with a frictional mechanism in a feeder for releasing substantially flat items from a stack, wherein the feeder has a driving mechanism for driving the flat items at a lower section of the stack through a nip, and the frictional mechanism is disposed near the nip so as to allow one flat item to pass through the nip at a time, wherein the frictional mechanism comprises at least a roller having a frictional surface disposed on a circumference of the roller, and a circumferential section of the frictional surface is in contact with the flat items at the lower section of the stack, said device is used to facilitate replacement of said circumferential section of the frictional surface with another circumferential section of the frictional surface. The device comprises:
a locking member having a plurality of facets forming a polygonal outer circumference of the locking member, each facet coving an angular section;
a shaft, disposed in relation to the nip, for securely mounting the roller, the shaft having a longitudinal axis substantially parallel to the nip, wherein the shaft has a longitudinal section for slideably mounting the locking member, allowing the locking member to move from a first portion of the longitudinal section to a second portion of the longitudinal section when needed, while preventing the locking member from rotating relative to the shaft; and
a blocking mechanism, disposed relative to the first portion of the longitudinal section of the shaft, such that
The locking member is rotated at least one angular section when the locking member is positioned at the second portion of the longitudinal section of the shaft, so that when the locking member is moved to the first portion of the longitudinal section of the shaft, a different one of the facets is substantially in contact with the blocking mechanism.
Preferably, the locking member has a non-circular cross section, and the longitudinal section of shaft has a substantially matching cross section for slideably mounting the locking member. Preferably, the non-circular cross section is polygonal in shape.
Preferably, the blocking mechanism comprises a surface which is in close proximity to said one of the facets when the locking member is positioned at the first portion of the longitudinal section of the shaft, and the surface is spaced from the locking member when the locking member when the locking member is positioned at the second portion of the longitudinal section of the shaft.
Advantageously, the feeder comprises a shaft mount for mounting the shaft for rotation about the longitudinal axis of the shaft, and wherein the blocking mechanism is fixedly mounted on the shaft mount.
Preferably, each of the flat items has two side edges substantially perpendicular to the nip, and said at least one roller comprises two rollers, each having a frictional surface disposed near a different one of the two side edges.
Preferably, the shaft has two ends for separately and fixedly mounting the rollers, and wherein the longitudinal section of the shaft is co-axially connecting the two ends.
According to the second aspect of the present invention, there is provided a method for replacing a first circumferential section of a frictional surface with a second circumferential section of the frictional surface in a feeder for releasing substantially flat items from a stack, wherein the feeder comprises:
a driving mechanism for driving the flat items at a lower section of the stack through a nip, and
a frictional mechanism disposed near the nip so as to allow one flat item to pass through nip at a time, the frictional mechanism having at least a roller for circumferentially mounting the frictional surface, the roller fixedly mounted on a shaft having a longitudinal axis substantially parallel to the nip, wherein the first circumferential section is in contact with the flat items at the lower section of the stack. The method comprises the steps of:
1) providing a locking mechanism comprising:
2) sliding the locking member from the first position to the second position;
3) rotating the locking member for causing the shaft to turn at least one angular section so as to allow the second circumferential section to contact with the flat items at the lower section of the stack; and
4) sliding the locking member from the second position to the first position.
According to the third aspect of the present invention, there is provided a feeder for releasing substantially flat items from a stack having a lower section. The feeder comprises:
a driving mechanism, disposed relative to the lower section of the stack, for driving the flat items at the lower section of the stack through a nip along a releasing direction; and
a frictional mechanism, disposed adjacent to the nip, for allowing one flat item to pass through the nip at a time, said frictional mechanism comprising:
Advantageously, the feeder can be used in an addressing machine for releasing envelopes. The feeder can also be used in a mailing machine for releasing enclosure documents into an insertion station where the released documents are inserted into envelopes. The feeder can be used to release sheets of paper in any paper handling machines, such as printers, photocopiers and the like.
The present invention will become apparent upon reading the description taken in conjunction with
The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
a is; a front view showing the frictional mechanism, according to the present invention, wherein the locking member is located at the locked position.
b is; a front view showing the frictional mechanism, according to the present invention, wherein the locking member is located at the unlocked position.
In describing the present invention, reference is made to the drawings, wherein there is seen in
The rollers 140 are securely mounted on a shaft 160 (see
The locking member 190 is basically a polygonal ring-like body having a plurality of facets 194. The locking member 190 also has a center opening 192 to fit the cross section of shaft 160. As can be seen in
As shown in
But when the locking member 190 is slid from the portion 166 to the portion 164 of the longitudinal section 162, as shown in
When the friction feeder 100 is in operation, the locking member 190 is located in the portion 166 of the shaft 160 in order to lock the separation rollers 140 in place. But, when it is desirable or necessary to replace the worn out surface section 152 with a fresh surface section 152′ (see
Preferably, the outer perimeter of the locking member 190 is hexagonal, formed by six facets 194. However, the number of facets can be any suitable integer, depending on the size of the locking member and the width of the contact section 152. The number of facets can be as small as three to form a triangle, and as large as twelve or more. Furthermore, the shape of the outer perimeter of the locking member 190 can be the same as the shape of the center opening 192, as shown in
It should be noted that the item 10, as shown in
Moreover, the blocking member 182, as depicted in
While the present invention has been disclosed and described with reference to a single embodiment thereof, it will be apparent, as noted above that variations and modifications may be made therein. It is also noted that the present invention is independent of the machine being controlled, and is not limited to the control of inserting machines. It is, thus, intended in the following claims to cover each variation and modification that falls within the true spirit and scope of the present invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4991831 | Green | Feb 1991 | A |
| 5163669 | Hurd et al. | Nov 1992 | A |
| 6485012 | Bakoledis | Nov 2002 | B1 |
| 6758468 | DaCunha et al. | Jul 2004 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20050082744 A1 | Apr 2005 | US |
