This invention was produced under a contract with the United States Post Office Department.
BACKGROUND OF THE INVENTION
This invention relates to an edger-stacker which is used for stacking media like letter mail on a long edge of the letters, with one vertical edge of the letters stacked being aligned in a vertical plane.
In recent years, there has been an increased effort to mechanize mail-handling operations in large post offices. Apparatuses to mechanize the stacking, sorting, facing, and cancelling of letter mail have already been produced. The present invention relates to an improvement in an edger-stacker apparatus.
Some of the prior-art edger-stackers are shown in the following United States patents: No. 2,926,910, Martin, Mar. 1, 1960, and No. 2,970,537, Wardwell et al., Feb. 7, 1961.
Some of the advantages of the present invention are as follows:
1. The invention is of simple design and is inexpensive to manufacture.
2. The invention can handle a wide range of sizes of media.
3. The invention provides an entrance for each piece of media, and has an orbital action, which facilitates edging.
SUMMARY OF THE INVENTION
This invention relates to an edger-stacker apparatus for stacking letter mail on a long lower edge of the letters. The apparatus includes a table for supporting the letters on their lower longitudinal edges, and an edger plate upstanding from the table. An input means feeds the letters in sequence to an entry point along a first direction, which is generally perpendicular to the edger plate. A stacking plate, upstanding from the table, has first and second portions. The first portion is located at the entry point to deflect a letter being fed along a second direction, which diverges away from the first direction, and the second portion is positioned along a direction which is parallel to the first direction. A letter backing plate means including a backing plate is used to urge letters already edged and stacked towards the second portion of the stacking plate. The second portion of the stacking plate has therein an opening through which a pusher plate may pass. The pusher plate is driven in an orbital path by a drive means which periodically advances the pusher plate through the opening in the second portion towards the backing plate and towards the edger plate as the pusher plate is advanced through the opening.
DESCRIPTION OF THE DRAWING
FIG. 1 is a general plan view of the invention showing an input means, a stacking plate, a letter-backing-plate means, an edger plate, a pusher plate, and drive means for moving the pusher plate.
FIG. 2 is a general elevational view of the invention showing more details of the drive means for moving the pusher plate and is taken from the direction A of FIG. 1. A part of the drive means is shown in cross-section.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a general plan view of the apparatus of this invention, which is designated generally as 10. The apparatus 10 includes a table 12, an input means 14, a feed area 16, a stacking plate means 18, an edger plate 20, a letter backing plate means 22, and a pusher plate means 24.
The input means 14 (FIG. 1) includes a pair of endless belts 26 and 28, which are respectively mounted on drive rollers 30 and 32, which are rotated at a constant angular rate in the direction of the arrows on the rollers by conventional drive means (not shown). The letter mail to be transported to the feed area 16 by the input means 14 is sandwiched between the belts 26 and 28, with a long edge of the letters positioned parallel to the table 12. The axes of rotation of the rollers are perpendicular to the table 12 and are offset slightly along the direction of travel of the letters, so that varying thicknesses of letters can be accommodated between the belts 26 and 28.
As the letters leave the belts 26 and 28 (FIG. 1), they travel in a first direction, which is perpendicular to the edger plate 20, which is vertically positioned on and secured to the table 12. Upon reaching the feed area 16, a letter being fed is deflected by a first portion 34 of the stacking plate means 18. The first portion 34 is a plate which is vertically positioned on and secured to the table 12. The first portion 34 is positioned at an angle (α) of about 25° from the first direction, so as to deflect a letter being fed along a second direction, which diverges away from the first direction. The stacking plate means 18 also includes a second portion 36, which is vertically positioned on and secured to the table 12. The plate means 18 is about 5 inches high and has a curved section 38 joining the first and second portions 34 and 36, respectively.
The letter backing plate means 22 (FIG. 1) includes a generally rectangular backing plate 40, which is mounted at its ends on slider bushings 42 and 44. The bushing 42 is slidably mounted on a rod 46, which is supported on conventional brackets (like 48), so as to position the rod 46 parallel to the table 12 and parallel to the edger plate 20. The bushing 44 is similarly mounted on a rod 50 by conventional brackets (like 52), so as to similarly position the rod 50 parallel to the table 12 and the edger plate 20. The brackets 48 and 52 each have a pulley 54 rotatably mounted thereon. A cable 56, having one end secured to the bushing 42, passes over its associated pulley 54 and has a weight (not shown) attached to the remaining end. Similarly, a cable 58, having one end secured to the bushing 44, passes over its associated pulley 54 and has a weight (not shown) attached to the remaining end. The backing plate 40, which is maintained in a position perpendicular to the table 12 by the construction just described, is used to resiliently urge a stack of letter mail already stacked and edged towards the second portion 36 of the stacking plate means 18. A stack of letter mail is shown in FIG. 1 by the dashed line 60, with the last letter inserted into the stack being numbered 62, the letters in the stack being positioned therein on their lower edges.
The pusher plate means 24, alluded to earlier, is shown in FIGS. 1 and 2. To accommodate the pusher plate means 24, the second portion 36 of the stacking plate means 18 has therein a rectangular opening 64 (FIG. 2). The pusher plate means 24 includes a pusher plate 66, with the right side 68 (as viewed in FIG. 1) having the arcuate shape shown. The plate 66 is secured to a supporting member 70 to be moved thereby. The member 70 has vertically-aligned bores (like 72) at opposite ends, which bores are provided with annular shoulders to conventionally support bearings 74 and 76, as shown on the left side of the member 70 (as viewed in FIG. 2). A shaft 78 is rotatably mounted in the bearings 74 and 76, and is internally threaded at one end to receive a fastener 80, which secures the member 70 to the shaft 78. SUitable washers 82 and 84 on the outer sides of the bearings 74 and 76 prevent axial movement of the member 70 on the shaft 78. The right side 86 of the member 70 is identical in construction to the left side thereof, just described. The lower end of the shaft 78 (as viewed in FIG. 2) is fixed to one end of a crank arm 88, whose remaining end is fixed to one end of a shaft 90 to be rotated thereby. The shaft 90 is rotatably mounted in a tubular member 92 passing through an opening in the table 12. The tubular member 92 has an annular flange 93 on its outer periphery, by which it is secured to the table 12. The shaft 90 is rotatably mounted in the tubular member 92 by a construction similar to that employed in mounting the shaft 78 in the member 70. The lower end of the shaft 90 is secured to a drive pulley 94 to be rotated thereby. A crank arm 96 (identical to the crank arm 88) is driven by a pulley 98 by a construction identical to that already described in relation to the crank arm 88. The crank arm 96 is also fixed to a shaft (not shown) which is identical to the shaft 78. Both pulleys 94 and 98 are driven in timed relation by a conventional timing belt 100, so that the crank arms 88 and 96 have the same angular displacement relative to a fixed plane like the one represented by the second portion 36 of the stacking plate means 18.
The pulleys 94 and 98 are rotated counter-clockwise (as viewed in FIG. 1), so as to produce an orbital motion in the supporting member 70. Because the pusher plate 66 is fixed to the member 70, it too will move in an orbital path while being maintained parallel to the second portion 36 of the stacking plate means 18. The pusher plate 66, as shown in FIG. 1, is in the process of moving towards the edger plate 20 while it is being moved towards the second portion 36. As it continues in this direction, it will eventually pass through the opening 64 in the second portion 36. As the cranks 88 and 96 are further rotated counter-clockwise, the pusher plate 66 will pass through the opening 64 in the second portion and push against the nearest letter 62 in the stack of letters and tend to edge the letter 62 towards the edger plate 20. In pushing against the nearest letter and the stack, an opening will be created between the letter 62 and the second portion 36. The next letter to be fed from the belts 26 and 28 will be deflected off the first portion 34 and be inserted between the letter 62 and the second portion 36 and be edged by the pusher plate 66. During the time that the pusher plate 66 is withdrawn through the opening 64, the opening created between the stack of letters and the second portion 36 will remain, because the stack of letters is not responsive enough to close the opening in the short time that the pusher plate 66 takes to emerge again from the opening 64. As letters are fed into the stack, they are maintained in an "on edge" position by the backing plate 40.
The apparatus 10 is designed to handle letter mail having the following dimensions:
Length -- 4.250 inches to 11.500 inches
Width -- 3.000 inches to 6.125 inches
Thickness -- 0.006 inch to 0.250 inch
Weight -- 0.1 ounce to 3.0 ounces
The specific dimensions selected for the various components of the apparatus 10 are, of course, dependent upon the particular application used. When handling media, like letter mail, having the above range of sizes, the discharge speed of the letters coming from the belts 26 and 28 is 145 inches per second, with an average of about 10 letters per second being fed to the feed area 16. The crank arms 88 and 96 make about 1,725 complete revolutions per minute. For a letter of average length, the pusher plate 66 will "edge" an incoming letter about three times prior to the entrance of the next letter being fed. The length of the stacking plate means 18 as measured by (d) on FIG. 1 represents the minimum length of letter which can be handled by the apparatus. The orbital motion of the supporting member 70 produces a vibration in the table 12, which facilitates the edging of the letters against the edger plate 20. As the stack of letters on the table 20 increases in size, the backing plate 40 moves away from the stacking plate means 18 to accommodate the larger stack.