GB2258458A - Method and apparatus for aligning while changing direction of flat articles - Google Patents

Description

1 -5 -, - -, - ;- Jr j I- METHOD AND APPARATUS FOR ALIGNING WHILE CHANGING

DIRECTION OF FLAT ARTICLES The present invention relates to an apparatus for receiving flat articles, changing their movement direction, and aligning them, and to a method and apparatus for simultaneously aligning and changing the direction of motion of flat articles; and in particular to a method and an apparatus for aligning while changing the direction of motion of mailpieces in an inserting machine.

Devices are known which turn flat articles, such as letter envelopes, within a plane. These devices are required where envelopes are discharged from an inserter and are not properly oriented to be fed to a downstream device such as a franking machine. An inserter is a machine that inserts selected items in an envelope for further processing. The filled envelope is sealed and then conveyed to a franking machine to have postage imprinted thereon. Generally, turner devices have the disadvantage of having to be an integral part of the inserting machine.

Examples of devices which turn flat articles in inserting machines are shown in U.S. Patent No. 4.726,461 issued February 23, 1988 to J. Pokrinchak and U.S. Patent No. 4,928,807 issued May 29, 1990 to D. Auerbach, both of which patents are assigned to the present Applicant.

It is known to change the direction of travel for flat articles without changing the orientation of the articles, i.e., without rotating or turning the articles. It is also known that for a one stage right angle change in direction the articles must be stopped in one direction before being conveyed in the right angled direction. Such a device is described in U.S. Patent No. 4,909,374 issued March 20, 1990 to M. Skrypalle and assigned to the present Applicant.

It is also known that a right angle change of direction for flat articles can be achieved in two or more stages by the use of deflection rollers which change the direction of travel by forty-five degrees (450) or less at each stage. Such an apparatus and method used in a sorting machine is disclosed in U.S. Patent No. 4,527,792 issued July 9, 1985 to G. Burkhardt. The Burkhardt apparatus has several limitations which prevent it from being usable in an inserting machine. The apparatus is limited to changing the direction of travel from a path parallel to a long edge of the mailpiece to a path of travel parallel to the short edge thereof. Furthermore, for all sized mailpieces, the Burkhardt apparatus requires a side-justified line of travel along the first direction of travel so that the deflection rollers can engage the article at the right moment to achieve an accurate change in direction. Typically, in an inserter, the center line of travel of the mailpiece is fixed with the side guides being adjustable for handling various sized mailpieces.

Several improvements in the throughput of various upstream modules (such as feeders, accumulators and insert stations) have raised the expectation that the output of the inserting machine will keep up with such improvements. However, when the output is increased on inserters which include conventional turner devices, the turner devices do not maintain the increased output rate. The turner devices are experiencing various problems when they are operated at higher speeds. For example, inserts are flying out of envelopes before the flap can be closed and turner components are malfunctioning.

In European patent application number 484177 published on 6 May 1992, and assigned to the present Applicant, a method and apparatus is disclosed for changing the direction of motion of flat articles being conveyed along a first path to a second path. The apparatus includes a deck having a first side for receiving an article from a first direction and a second side for conveying the article in a second direction which forms an acute angle equal to or less than forty- five degrees (450) with the first direction. There is a structure which includes a plurality of angled roller pairs for conveying the article over the deck in the second direction. The conveying structure engages a leading edge of the article only after the article has been disengaged by a conveying structure in the first direction. There is a registration wall positioned downstream from the second direction conveying structure adjacent a third side of the deck. The registration wall extends a third direction whereby the registration wall is at a right angle to the first direction, wherein the leading edge of the article is driven against the registration wall after the article has been disengaged by the second direction conveying structure. There is a structure for conveying the article in the third direction after the article is against said registration wall.

Although the foregoing apparatus and method has worked well changing the direction of travel of the article from a first direction to a second direction, the structure for handling the article in the third direction experienced some problems. The registration wall in combination with an angled roller assembly performs the dual function of conveying the article in the third direction and aligning the article against the registration wall. In practice, when the article was conveyed at high speed, it crashed into the registration wall and rebounded away from the wall while being conveyed in the third direction. Another problem experienced was the catching of the inner lip of the envelope against the roller angled at 45 degrees, which caused skewing and crumpling.

Other known alignment devices were tried in an attempt to solve the aforementioned problems, however such devices are typically intended to align articles travelling in one direction. An example of such alignment devices is the modular device disclosed in U.S. Patent no. 5,022,638, issued January 11, 1991 to E. Movits and assigned to the present applicant. --- The Ifkovits alignment device, which includes bottom driven rollers parallel to the registration walls and pressure rollers angled slightly towards the registration wall, did solve the problems of rebounding, skewing and crumpling, however an assembly of several modules was required before the article became registered against the registration wall.

is It has been found that changing the direction of travel for flat articles conveyed at high speeds requires an alignment device which controls the article such that it immediately urges the article against a registration wall without impeding the movement of the article in the new direction. It has further been found that free floating roller balls suspended over angled driven rollers provides suitable control for meeting the aforementioned requirement. The method and apparatus of the present invention has been found to reduce by one third the time and length of travel for the envelope to become aligned while changing direction.

In an inserting machine, an apparatus for receiving envelopes being conveyed in a first direction and conveying and aligning the envelopes in a second direction, includes a deck mounted to a frame and a registration wall adjustably positioned on the deck and extending in the second direction. There are a plurality of driven rollers situated below the deck and oriented in the first direction, and extending through slots in the deck for conveying the envelopes. A roller ball assembly is suspended over at least one of the driven rollers, for providing a normal force against the driven roller, wherein the driven rollers convey the envelopes in the first direction until the envelopes engage the wall and wherein the driven rollers convey the envelopes in the second direction after the envelopes have engaged the wall.

The roller ball assembly comprises at least one roller ball which is superposed over one of the driven rollers and which is suspended through an aperture in a support plate mounted above the deck, whereby the roller ball is rotatable in any direction. In one embodiment the driven.2ollers are oriented at a 45 0 with respect to the wall.

A complete understanding of the present invention maybe obtained from the following detailed description of the preferred embodiment thereof, when taken in conjunction with the accompanying drawings wherein like reference numerals designate similar elements in the various figures, and in which

Fig. 1 is a plan view of a forty-five degree take away unit connected to an alignment apparatus in accordance with the pre sent invention configured to change the direction of travel to the left.

Fig. 2 is a front view of the alignment apparatus in Fig. 1 taken along lines 2-2 with portions broken away to show the invention more clearly.

Fig. 3 is a side view of the alignment apparatus in Fig. 1 taken along lines 3-3.

Fig. 4 is a plan view of the forty-five degree take away unit connected to the alignment apparatus in Fig. 1 configured for changing the direction of travel to the right.

Referring now to the Figures and in particular to Figure 1, there is shown a take away unit, generally designated 10, and an alignment apparatus in accordance with a preferred embodiment of the present invention, generally designated 12. Take away unit 10 includes a deck 14 having an input side 16 and an exit side 17. The deck is provided with 8 rectangular slots 18 with each of slots 18 having projected in part a continuously driven roller (not shown) above which an idler roller assembly 20 is suspended. Below deck 14 is a motor 22, preferably a variable speed motor, including a typical shaft and pulley drive system, generally designated 24, for driving the driven rollers. Take away unit 10 is conf igured at a 45 0 angle from the upstream device for changing direction of envelope 26 filled at insert station 28 for further processing downstream from the take away unit. Take away unit 10 can be configured at other angles less than 45'. A more detailed description of take away unit 10 is provided in the said European Patent Application No. 484,177, the subject matter of which is incorporated herein by reference.

Take away unit 10 is particularly suited for changing the direction of travel of envelope 26 by 900 in lieu of turning the envelope for further processing. As described in the aforementioned application, take away unit 10 changes direction of travel for envelope 26 by no more than 45' and an alignment apparatus, which both aligns the envelope and changes direction of the envelope is required to change the direction of travel the balance of the 900.

In this embodiment of the present invention, alignment apparatus 12 includes a registration wall 30 adjustably mounted to deck 31. There are four driven rollers 32, 34, 36 and 38 which are located below deck 31 and which are projected in part through four rectangular slots 40 in deck 31. Below deck 31, there is a conventional drive system, similar to drive system 24, which includes motor 42, preferably of a variable speed type, and a belt and pulley configuration for driving rollers 32, 34, 36 and 38.

Rollers 32, 34, 36 and 38 are angled 45' towards registration wall 30 for conveying the envelope 26 in two directions, i.e., towards the registration wall 30 and towards the downstream device 50, for example, a device for sealing envelope 26. It has been found that the angle of rollers 32, 34, 36 and 38 should match the angle of the driven rollers of take away unit ID to prevent any is unnecessary skewing of the envelope as it passes from the control of take away unit 10 to alignment apparatus 12. It will be appreciated that the number of rollers is not limited-to the four rollers described in the preferred embodiment of the present invention.

It has been found that the type and amount of normal force applied to rollers 32 and 34 is a significant element for alignment apparatus 12 to immediately register envelope 26 against wall 30 without the problems experienced with other alignment devices. Normal force can be applied to the other rollers. In the preferred embodiment of the present invention, normal force is applied to rollers 32 and 34 by a pair of free floating roller balls 54 and 56 each of which is suspended in a roller ball retaining assembly generally designated 58. Roller ball retaining assembly 58 includes a mounting block 60 rigidly connected to an edge of deck 31 which is opposite registration wall 30. In the preferred embodiment of the present invention, mounting block 60 is cut away at the bottom of the upstream end so that it does not interfere with the handling of larger sized envelopes. Two rigid shafts 62 and 64, for example, thick steel shafts, are rigidly mounied at one end to mounting block 60, and at the other end to a suspending plate 66, whereby suspending plate 66 is cantilevered over rollers 32 and 34. Suspending plate 66 has two apertures through which a pair of cups 70 are inserted for holding free floating roller balls 54 and 56. Each cup 70 has an upper rim which sits on plate 66. There are a pair of caps 72 which fit into cups 70 and rest over roller balls 54 and 56. A leaf spring 74 is secured to the center of plate 66 by screws 76 and each end of leaf spring 74 sits on one of caps 72. In the preferred embodiment of the present invention, each cap 72 is slotted for receiving an end of leaf spring 74. Leaf spring 74 applies a force against caps 72, which in turn apply pressure to roller balls 54 and 56. Roller balls 54 and 56, cups 70 and caps 72 can easily be replaced by lifting the respective end of leaf spring 74 to remove the cap, cup and ball. In the preferred embodiment of the present invention, a plastic-like material is used for the cup, cap and ball to minimize the normal force applied to roller balls 54 and 56.

It will be understood that roller balls 54 and 56 rotate in any direction and do not impede the sudden change in direction when the envelope hits registration wall 30. In the preferred embodiment of the present invention, cups 70 are made of Rulon and caps 72 and balls 54 and 56 are made of Delrin. It has been found that the light weight and wear resistant characteristics of such material minimizes the normal force applied against rollers 32 and 34 and reduces the wear of roller balls 54 and 56 as they rotate within cups 70. In particular, caps 72 serve as a buffer between the conventional metal leaf spring 74 and the free floating roller balls 54 and 56. The self-lubricating and high wearing resistance characteristics of Delrin make it suitable for using Delrin as the material for caps 72 and roller balls 54 and 56.

The disclosed arrangement is suitable for handling envelopes of various thickness without the need to adjust the normal force applied by roller balls 54 and 56. When thick envelopes pass under roller balls 54 and 56, leaf spring 74 flexes while providing adequate tension for rollers 32 and 34 to maintain control of the envelope. In the preferred embodiment of the present invention, leaf spring 74 applies two ounces of pressure on each cap 72 and the weight of each of the free floating roller balls 54 and 56 is 24 grams. It will be understood that light-weight materials having similar characteristics could be used as well.

It will be understood that other means of applying normal force can be used as the envelope is conveyed by rollers 32, 34, 36 and 38. For example, a light weight strap laying across the-deck 31 can be used to maintain contact between the envelope and the rollers. It will further be understood that the normal force can be applied to just one or all of the rollers.

Another important feature of the illustrat-ed apparatus is chamfered edges 80 of rollers 32, 34, 6 and 38. It has :b 9 - been found that when conveying open envelopes face down at a 450 angle at a high speed into a registration wall the throat of the envelopes can be caught on the edge of the angled rollers causing the envelopes to crumple. It has further been found, that by using rollers with chamfered edges on the side of the rollers receiving the envelopes eliminates this problem. In the preferred embodiment of the present invention the chamfered edges are at 450.

In the preferred embodiment of the present invention, with take away unit 10 operating at 10,000 cycles per hour and moving envelopes at 87 inches per second (22.1 metres per second), the optimum speed for alignment apparatus 12 is 252 inches per second (64 metres per second). Such a speed ratio of almost 3 to 1 is considered optimum for two reasons. First, there is an X component and a Y component of the speed of 178 inches per second (45.21 metres per second), where the X component is into registration wall 30 and the Y component is along registration wall 30 towards the downstream unit 50. In accordance with the preferred embodiment of the present invention, once alignment apparatus 12 takes control of envelope 26 from take away unit 10, alignment apparatus 12 moves envelope 26 at least as fast as take away unit 10 was conveying the envelope. Considering the normal force of two ounces on envelope 26 as the envelope enters the nip of the rollers 32 and 34 and roller balls 54 and 56 respectively, and further considering the different possible weights of envelope 26, it has been found that envelope 26 is moving at less than the speed of the X and Y components. It has further been found that by using the optimum speed envelope 26 will always travel at least 87 inches per second towards the downstream unit 50 thus preventing a problem with the next envelope conveyed by take away unit 10.

In operation, envelope 26 (shown in phantom) is conveyed along a 450 path from insert station 28 by take away unit 10 to alignment apparatus 12. When envelope 26 enters the nip of roller 32 and roller ball 54, the envelope is urged against registration wall 30. Envelope 26 is then conveyed by rollers 32, 34, 36 and 38 along registration wall 30. If envelope 26 enters the nip of roller 32 and roller ball 54 skewed, the envelope is quickly deskewed by rollers 32 and 34 urging envelope 26 against registration wall 30. The normal force applied by roller balls 54 and 56 against rollers 32 and 34 prevents envelope 26 from bouncing off the wall. It will be understood that the combined effort of rollers 32 and 34. roller balls 54 and 56, and registration wall 30 provides a quick and lasting alignment of envelope 26 against registration wall 30.

Referring again to Fig. 1, typically the downstream apparatus 50 in an inserter will be a sealer station which typically has a stationary crease line 27 for envelope flaps and a registration wall 28 which is adjustable to. handle different sized envelopes. Registration wall 30 of alignment apparatus 12 is adjustable for handling different sized envelopes so that the flap crease line of the envelope corresponds to crease line 27 in sealer station 50. Registration wall 30 is mounted to deck 31 by a pair of blocks 90. Each block 90 has a slotted hole 92 for adjustably positioning block 90 over a tapped hole 94 in deck 31 whereby a screw 96 is inserted into hole 94 to secure the position of each block 90. Registration wall 30 is secured to blocks 90 in a conventional manner, such as recessed screws. In the preferred embodiment of the present invention, registration wall 30 has a coating, for example teflon, over the wall face to reduce friction as envelope 26 is aligned and conveyed against the wall.

Referring now to Fig. 3, registration wall 30 has a beveled edge 33 which rests slightly below the lower edge of the interior end of blocks 90. The exterior end of each block 90 has a step 98 extending lower than the rest of block 90. When screw 96 is tightened, steps 98 prevents the exterior end of block 90 from fitting flush against deck 31. This ensures that no gap exists between deck 31 and registration wall 30. Step 98 facilitates the adjustment to the position of registration wall 30 by eliminating the possibility of a gap. it will be appreciated by those skilled in the art that step 98 in adjustably positioned block 90 is an alternate method for ensuring that no gap ii exists between deck 31 and registration wall 30. Other methods can be used, such as, having a grooved section of the deck whereby the registration wall is lowered into one of the grooves to ensure no gap exists between the deck and the registration wall Referring now to Figure 4, the apparatus is generally similar to that shown in Figure 1, but of the opposite hand. It is shown conveying and aligning an envelope to the right when take away unit 10 is conveying the envelope in that direction.

While the present invention has been disclosed and described with reference to a single embodiment thereof, it will be apparent that variations and modifications may be made therein, without departing from the invention. jr,'

Claims (14)

1. An apparatus for receivi-ig flat articles being conveyed seriatim in a first direction and conveying and aligning each flat article in a second direction, comprising:

deck mounted to a frame; registration wall positioned on the deck, said wall -extending in said second direction; a plurality of driven rollers situated below said deck and oriented in the first direction, said rollers extending through slots in said deck for conveying the article; means for applying a normal force to the article while the article is conveyed by said driven rollers, wherein said driven rollers maintain control of the article before and after the article hits said registration wall.

2. The apparatus according to claim 1 wherein said normal force means comprises a roller ball assembly suspended over at least one of said driven rollers, said roller ball assembly providing a normal fqrce against said driven roller, wherein said driven rollers convey the article in the first direction until the article engages said wall and wherein said driven rollers convey the article in the second direction after the article has engaged said wall.

3. The apparatus according to claim 1, wherein said driven rollers are oriented at a 45 0 with respect to said wall.

4. The apparatus according to claim 2, wherein said roller ball assembly comprises at least one roller ball superposed over one of said driven rollers, said roller ball being suspended through an aperture in asupport plate mounted above said deck, said roller ball being rotatable in any direction.

5. The apparatus according to claim 4, wherein said roller ball assembly further comprises a cup for holding said roller ball suspended over said driven roller, said cup having a lower portion extending through said aperture and an upper rim resting on said support plate.

6. The apparatus according to claim 5, wherein said roller ball assembly further comprises a spring means for applying tension against said roller ball and a cap situated in said cup between said spring means and said roller ball.

7. The apparatus according to claim 6, wherein said spring means comprises a leaf spring mounted to said support plate, wherein one end of said leaf spring is resting on said cap.

8. The apparatus according to claim 4, wherein said support plate is cantilevered over said deck by a mounting block secured to an side of said deck opposite said registration wall, said block being connected to an end of at least one rigid shaft, the other end of said shaft being connected to said support plate.

9. The apparatus according to claim 1, wherein said registration wall is connected to a pair of support members, said support members being adjustably mounted to said deck whereby said registration wall is adjustably positioned.

10. The apparatus according to claim 9, wherein each of said support members includes a slotted section, each of said support members being secured to said deck by a screw extending through said slotted section into a tapped hole in said deck.

11. The apparatus according to claim 10, wherein each of said support members has a short leg at an end not connected to said registration wall.

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12. The apparatus according to claim 10, wherein said registration wall includes a beveled edged which is flush with said deck when said support members are secured to said deck.

13. The apparatus according to claim 1, wherein said driven rollers have a chamfered edge.

14. A method of aligning a flat article being conveyed ii a first direction as the article is conveyed in a second direction, comprising the steps of:

a) conveying the article by driven rollers in the first direction towards a registration wall; b) pre.viding a roller ball assembly superposed over said driven rollers for obtaining positive control of the article by applying a normal force to the article while the article is conveyed by said driven rollers; and c) conveying the article by said driven rollers in the second direction when the article hits said registration wall.

An apparatus for receiving flat articles being conveyed seriatim in a first direction and conveying and aligning each flat article in a second direction substantially as herein described and illustrated with reference to and as illustrated in the accompanying drawings. 16. Any novel feature or combination disclosed and/or illustrated heroin.

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