JPH0557032B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mail sorting device, and in particular, the present invention relates to a mail sorting device that allows a person to read the address and postal code written on the mail and electronically input it by typing on a keyboard. This invention relates to a mail supply device for a coding desk suite in which several coding desks are connected to each other to code the mail.

[Conventional technology]

Conventionally, in this type of coding desk suite, as shown in FIG.
43773, it is accumulated at the accumulation site 107.
Then, the mail pieces are sequentially processed by the operators of each coding desk, and the number of mail pieces at the collection point of each coding desk gradually decreases. When the amount of mail decreases to a certain amount, collection point 1
A detector installed at 07 detects the mail, and the supply section automatically supplies the mail to the collection point 107, and the mail is controlled so that the mail is always accumulated at the collection point.

[Problem that the invention seeks to solve]

At the collection point 107, which is a well-known fact as the final stage of many mail handling devices,
The next mail item is stacked while being slid onto the surface of the mail item that has already been stacked. In the final stage, that is, in the stage where there is no automatic processing again in the device after stacking (such as taking out mail pieces one by one after stacking), there are few restrictions on the orientation in which the mail is stacked (for example, front and back, top and bottom, left and right directions), and this final At this stage, a person always intervenes to take out the accumulated mail.

However, in the case of the Coding Desk Suite in question, once the mail has been accumulated at the collection point, it is necessary for the mail to be automatically retrieved one by one in front of the person typing the key. In order to retrieve the mail, the address and postal code on the mail must be visible to the person typing the key. That is, there are conditions such as there are restrictions on the direction and posture when stacking mail, and because it is not the final stage, it is not a place where human intervention would be required.

There is no problem if the mail envelopes handled by the device are completely sealed. However, in reality, the first
There are many envelopes as shown in Figure 6. 16th
Figure a shows the folded part 1 at the envelope manufacturing stage.
This shows an envelope in which glue is not applied to the entire glue-applied part of No. 08, and in particular, the folded end is not glued. Figure 16b shows an envelope with a stapled lid for inserting the contents.
Figure 16c shows an envelope whose lid itself is not closed at all, and which is often seen in direct mail, called a kaifeng.

Now, when these envelopes are accumulated one after another at the collection station, as shown in Figure 17, they get stuck on the lids of the previously accumulated mail, and this condition continues to cause jams (hereinafter referred to as jams). call) occurs. Therefore, each time the device is stopped in order to prevent damage to the mail, the effect of introducing the device is not improved at all, and a situation occurs where the device is no longer usable.

This problem has become more serious as we enter an era of diversification, and the number of types of mail envelopes continues to increase.However, this problem has become more serious in equipment that automatically processes mail, especially the coding desk suite that is featured in this invention. I deepened my degree. Unlike other automatic processing devices, the stacking operation is not the final step, so there are restrictions on the direction and posture of the mail, which means that the mail must be stacked on the side that is more likely to hit the lid, etc. mentioned above. The condition is that it is not a place where human hands are constantly required to correct the situation and prevent the equipment from stopping in advance.

Furthermore, as mentioned above, it is currently impossible to expect mail items to be completely sealed, and conventional devices have the major practical problem of frequently being forced to stop, resulting in lower operating rates. was.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a mail feeder for a coding desk suite that can process the mail shown in FIG. 16 without any problems.

[Means for solving problems]

The mail supply device of the coding desk suite of the present invention includes: a mail supply section; a conveyance means having one end of a conveyance path connected to the mail supply section; and a conveyance means connected to the other end of the conveyance path of the conveyance means. A loop-shaped conveyance means having a loop-shaped conveyance path, a plurality of branch paths provided on the loop-shaped conveyance path, a single mail stacking mechanism provided at the end of each branch path and for accumulating only one piece of mail, and a single mail stacking mechanism A first photoelectric detector is provided in front of the entrance of each branch path of the loop-shaped conveyance path to detect the leading edge of the mail items conveyed through the loop-shaped conveyance path. a second photoelectric detector for detecting; and between the entrance of each branch path and each second photoelectric detector;
A switch provided along the loop-shaped conveyance path, and a loop-shaped point provided so that the optical axis is perpendicular to the loop-shaped conveyance path, and from the optical axis to the point where the loop-shaped conveyance path and the conveyance path intersect. The distance in the conveyance direction of the conveyance path is longer than the distance of the conveyance path from the end of the mailpiece to the point when the mailpiece is taken out by the mail supply unit by an amount that allows the mailpieces to be lined up at a minimum interval, and A third photoelectric detector detects the tip of the mail that has not been branched into the single mail stacking mechanism, and the optical axis is perpendicular to the loop-shaped conveyance path and is installed at a position upstream of the third photoelectric detector. a fourth photoelectric detector provided between the fourth photoelectric detector and the third photoelectric detector, which is part of the loop-shaped conveyance path but driven by a drive source different from that of the loop-shaped conveyance means; The first photoelectric detector detects that no mail is accumulated in the one-piece stacking mechanism, and the first photoelectric detector detects that no mail is accumulated in the one-piece accumulation mechanism. Sometimes, when the second photoelectric detector corresponding to the one-piece stacking mechanism detects the leading edge of the mail piece, the switch corresponding to the one-piece stacking mechanism is operated for a time such that only one piece of mail is separated. , when the third photoelectric detector is not blocked by the mail for a period of time corresponding to the interval at which one mail can be inserted, causes the supply unit to feed the mail, and detects the leading edge of the mail. stops the supply of mail to the supply unit, determines the two intervals between three successive pieces of mail conveyed through the loop-shaped conveyance path by the fourth photoelectric detector, and calculates the distance between these three pieces of mail. When the spacing is not large enough to insert a single piece of mail, but is too large for the person who presses the key to request the mail immediately, the pause mechanism pauses the mail that is located in the middle of three consecutive pieces of mail. The control unit is provided to ensure that the distance between the previous two pieces of mail is at least a size that allows one piece of mail to be inserted.

[Effect]

As a solution, if two or more pieces of mail are not stacked at the collection point, mail pieces will not get jammed and jams will not occur, so it is only necessary to stack one piece of mail. However, if only one piece of mail is accumulated at the collection point using the means shown in FIG. Immediately after the mail is emptied, it takes 2 to 3 seconds for the mail to be transported from the supply section to the collection point.
During that time, the person who has completed the keystroke must wait until the next mail arrives. In other words, there will be idle time for work, and work efficiency will not improve. It is also not possible to predict when a collection point will be empty and supply mail in order to reduce free time. This is because the processing time for each postal item is not the same since humans read the postal code and process the postal items. Further, the method of forcibly feeding mail items in front of the key presser at the same cycle should not be used from an ergonomic standpoint.

As a solution to this problem, the present invention installs a loop-shaped mail conveying means between a conveyance path for conveying mail taken out from a supply section and a single-letter collection point, and transfers this loop-shaped mail conveying means to a single-letter collection point. The loop-shaped conveyance means is installed nearby, and the presence or absence of mail in the loop-shaped conveyance means is controlled so that the loop-shaped conveyance means can immediately supply one mail piece to the collection point, and the loop-shaped conveyance means is always filled with mail. Check the supply unit's supply start/
In addition, a means for measuring the distance between mail items and a mail temporary stop mechanism are provided at one point of the loop-shaped conveyance means, and the distance detected by this measuring means is such that a mail item can be inserted. If the size of the mail is not exceeded, the mail is stopped while being held between a pair of opposing belts, and the distance between the following mail is changed, and the space for the previous mail is widened to secure space for the mail. It was designed to do so.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a general view of one embodiment of a mail supply apparatus for a coding desk suite of the present invention. One end of a conveyance path 2 is connected to the supply section 1, and the other end is connected to a loop-shaped conveyance path 3. The loop-shaped conveyance path 3 includes a plurality of (six in this embodiment)
Branch roads 4 to 9 are arranged, and one-way collection points 10 to 15 are arranged at the other ends of the branch roads 4 to 9. In addition, near the intersection of the loop-shaped conveyance path 3 and the branch paths 4 to 9, along the loop-shaped conveyance path 3, a
The point devices 16 to 21 described in 1 are arranged, and photoelectric detectors 22 to 27 are arranged in the vicinity thereof so that their optical axes intersect with the loop-shaped conveyance path 3. Furthermore, a photoelectric detector 2 intersects with the loop-shaped conveyance path 3.
8, 29 are arranged, and these photoelectric detectors 28, 2
A temporary stop mechanism 30 is provided in a part of the loop-shaped conveyance path 3 between the two portions 9, and a photoelectric detector 31 is installed to intersect with this temporary stop mechanism 30.

Next, the configuration of each part will be explained in detail with reference to FIGS. 2 to 11.

2 to 4 are diagrams showing the configuration of the supply section 1. FIG. A suction belt 32 having holes for suction is placed horizontally on rollers 33 and 34, a belt tension roller 35, and a drive roller 36, and has a large number of through holes attached closely to the front surface of a vacuum chamber 37. It is in contact with the front plate 38. A photoelectric detector 39 is installed at a height that intersects the suction belt 32 and passes through the suction holes of the suction belt 32 . Drive roller 36
is connected to a clutch 41, a pulley 42 and a brake 43 with respect to a shaft 40, as shown in FIG. Clutch 41 and brake 43 are fixed to the base plate.

FIG. 5 is a diagram showing the configuration of the conveyance path 2. The conveyance path 2 includes a large number of rollers 44 and a pair of belts 45 ₁ ,
45 ₂ , and the belts 45 ₁ and 45 ₂ are stretched across a large number of rollers 44 . This conveyance path 2
is connected at one end to the supply section 1 described in FIG. 3.

FIG. 6 is a diagram showing the configuration of the loop-shaped conveyance path 3. As shown in FIG. 6, the conveyance path 2 is connected to the loop-shaped conveyance path 3 at the other end. As shown in FIG.
Consisting of a large number of rollers 6 to 57, the belt 46
57 are horizontally suspended over a large number of rollers, and form a loop-shaped conveyance path 3 with a pair of belts. Six branch paths 4 to 9 are arranged in the loop-shaped conveyance path 3,
Each branch path 4 to 9 is a pair of belts 47 and 58,4
8 and 59, 49 and 60, 51 and 61, 52 and 62
and 53 and 63, each belt 47 to 6
3 is horizontally suspended over a large number of rollers. Branch road 4~
One end of 9 is connected to the loop-shaped conveyance path 3, and near the branch path there is a switch 16 as explained in FIG.
21 and photoelectric detectors 22 to 27 are installed. Further, the other ends of the branch paths 4 to 9 are connected to one-way collection points 10 to 15. Belts 46 to 63 forming loop-shaped conveyance path 3 and branch paths 4 to 9
(excluding 55 and 56) are driven by the same drive source (not shown) as the belts 45 ₁ and 45 ₂ that constitute the conveyance path 2.

FIG. 7 and FIG. 8 are diagrams showing the configuration of the one-letter collection points 10 to 15. As shown in _FIG .
64 ₂ and rollers 65 ₁ , 65 ₂ and drive roller 6
6 ₁ , 66 ₂ and a photoelectric detector 67. The drive rollers 66 ₁ and 66 ₂ are connected to pulleys 68 ₁ and 68 ₂ by shafts 69 ₁ and 69 ₂ , as shown in FIGS. 7 and 8. Pulley 68 ₁ ,
68 ₂ is connected by a belt 72 to a drive pulley 71 that is engaged with a clutch brake 70 . At the other axial end of the clutch brake 70, a driven pulley 73 is connected to a pulley of a motor (not shown) by a belt 74.

9 and 10 are diagrams showing the structure of the temporary stop mechanism 30. FIG. As shown in FIG. 9, the temporary stop mechanism 30 includes a pair of belts 55, 56 and a roller 7.
5 ₁ , 75 ₂ , drive rollers 76 ₁ , 76 ₂ , and a photoelectric detector 31 . The drive rollers 76 ₁ and 76 ₂ are connected to pulleys 77 ₁ and 77 ₂ by shafts 78 ₁ and 78 ₂ , as shown in FIGS. 9 and 10. The pulleys 77 ₁ , 77 ₂ include a drive pulley 80 engaged with the clutch brake 79;
They are connected by a belt 81. At the other end of the clutch brake 79 in the axial direction, a driven pulley 82 is connected to a pulley of a motor (not shown) by a belt 83. The configuration of this temporary stop collection 30 is exactly the same as that of the one-time collection stations 10 to 15. The name has been changed due to the difference in date.

FIG. 11 shows the control section 84 that controls each component of this embodiment, and its inputs and outputs. On the input side of the control unit 84, an output signal 85 of the photoelectric detector 39, an output signal 86 of the photoelectric detector 28, and an output signal 87 of the photoelectric detectors 22 to 27 (six in total in this embodiment, but the same Therefore, the output signal 88 of the photoelectric detector 67 (same as in the box above), the output signal 89 of the photoelectric detector 29, and the output signal 90 of the photoelectric detector 31 are connected. There is. Further, on the output side of the control section 84, a drive input 91 of the clutch 41, a drive input 92 of the brake 43, and the switch 16 to 2 are connected to the output side of the control section 84.
1 drive input 93 (in this embodiment, there are six in total, but since they are the same, one is representative to avoid duplication), the drive input 94 of the clutch brake 70 (same as in the above bracket), and the drive input of the clutch brake 79. The inputs 95 are each connected to the control section 84 via a drive circuit.

Fig. 12 is a diagram showing the drive current of the pointers 16 to 21, Fig. 13 is a diagram showing the flow of mail, and Fig. 14 is a diagram showing the flow of mail.
The figure is an explanatory diagram regarding the distance between mail items.

Next, the operation of this embodiment will be explained with reference to FIGS. 12 to 14. First, I will explain the overall operation, and then I will explain the operation of each part. Mail pieces are continuously taken out one by one from the supply section 1 and are conveyed to a loop-shaped conveyance path 3 through a conveyance path 2. Since it is confirmed by the photoelectric detector 67 that there is no mail in the mail collection points 10 to 15, the switches 16 to 21 operate according to this output signal 88 to remove the mail. One collection point 1 from the loop-shaped conveyance path 3
0 to 15 through branch paths 4 to 9. After the photoelectric detectors 22 to 27 confirm the leading edge of the mail being conveyed, the leading edge of the mail is detected by the pointer 16.
-21, the switch 16-21 switches to the 12th
As shown in the figure, it is controlled by the drive input 93 from the control section 84 so as to operate for 40 msec. Since the belt speed of the loop-shaped conveyance path 3 is 3 mm/ms, only the leading edge side of the mail piece 120 mm is passed through the pointer 16~
21 operates to change the conveyance direction of the mail to the branch paths 4-9. Since the minimum length of mail that can be handled by the apparatus of this embodiment is 140 mm, only one mail is branched by this 40 ms operation, and there is no effect on subsequent mail. In this way, only one copy is branched and transported to one-copy collection points 10-15.

Now, the mail pieces successively taken out one by one from the supply section 1 are sequentially accumulated in the empty one-piece collection stations 10 to 15. The mail items that have not been branched to the single collection stations 10 to 15 are conveyed as they are along the loop-shaped conveyance path 3, and at a certain time are in the state shown in FIG. 13a. That is, when the leading edge of the mail piece 96 reaches the photoelectric detector 28, the supply unit 1 automatically stops supplying the mail piece. The reason for this is to prevent the mail conveyed from the supply section 1 and the mail conveyed through the loop-shaped conveyance path 3 from overlapping at the confluence of the conveyance path 2 and the loop-shaped conveyance path 3. . 13th
FIG. b is a diagram showing the state when the mail piece 96 passes through the photoelectric detector 28. No mail has been taken out after mail 97. FIG. 13c shows the state after a further minute period of time has elapsed. The end of the mail piece 98 and the mail piece 99 conveyed through the loop-shaped conveyance path 3
If the distance between the tips of the mail pieces 100 is 450 mm or more, the supply unit 1 takes out one piece of mail 100. This length of 450 mm is determined by constantly detecting the spacing between mail items using the photoelectric detector 28, calculating the time by counting clock pulses using a counter circuit in the control unit 84, and multiplying the time by the conveying speed of 3 mm/ms. It is required by certain things.

Now, as shown in FIG. 13c, it was confirmed that the distance between the mail pieces 98 and 99 was 450 mm or more, so the supply section 1 took out the mail piece 100. However, since the leading end of the mail piece 99 shielded the photoelectric detector 28 from light, the supply unit 1
Naturally, it stops immediately after taking it out. FIG. 13d is a diagram showing the state after the elapse of the minute time shown in FIG. 13c. Here, in front of the mail piece 96 that was being conveyed on the loop-shaped conveyance path 3, the mail piece 97 that was conveyed from the supply section 1 without overlapping is being conveyed. This means that if the distance from the lower end of the supply section 1 to the confluence of the conveyance path 2 and loop-shaped conveyance path 3 is _L1 , and the distance from the photoelectric detector 28 to this confluence is _L2 , then
This is because it is set so that L ₂ =L ₁ +70 mm, and the mail conveyance speed of the conveyance path 2 and the conveyance speed of the loop-shaped conveyance path 3 are the same, 3 mm/ms. Therefore, the mail items 96 and 97 are lined up with an interval of at least 70 mm.

Now, as a practical problem, the interval between mail pieces conveyed through the loop-shaped conveyance path 3 may vary depending on various conditions.
The situation shown in Figure 4 may occur. Here, the distance 103 between the mail piece 101 on the forward side in the traveling direction and the next mail piece 102 is 350 mm, and the mail piece 10
2 and the distance 105 between the mail 104 is 200 mm,
These numbers, such as 350mm and 200mm, are not limiting and are merely given as examples. In this case, it is assumed that it is impossible to insert one piece of mail from the supply section 1 through the conveyance path 2 within a 350 mm interval. 450mm or more is required. In fact, this value is related to the accuracy of the operation of the elements that make up the feeding section 1 and the stability of the speed of the belt that conveys the mail, and is the currently required spacing to prevent mail from overlapping at the confluence point. . If the condition shown in FIG. 14 occurs many times in the loop-shaped conveyance path 3, it is not possible to replenish the mail items from the supply section 1 through the conveyance path 2, so the distance between each mail item remains unchanged from the branch path 4 to the conveyance path 2. 9, so even if the person who typed the key asked for the mail, he or she could not get it right away.
If there is an interval of , the phenomenon that it takes 117ms will occur. As a solution to this, a temporary stop mechanism of 0
and a photoelectric detector 29 are installed on the loop-shaped conveyance path 3. Based on the signal from the photoelectric detector 29, the control unit 84 calculates the distance between the mail items. For example, in the situation shown in Figure 14,
The temporary stop mechanism 30 holds the mail 102 on the belt 55,
56, and change the inter-mail distance 105 from 200 mm to 60 mm in Fig. 14. Therefore, the inter-mail distance 103 changes from 350 mm to 490 mm. As mentioned above, the distance of 490 mm is sufficient to insert one piece of mail, and after the photoelectric detector 28 detects the distance, the supply section 1 takes out the mail.

Next, the operation of each part will be explained.

The supply unit 1 operates based on the signal from the photoelectric detector 28, and the control unit 84 counts clock pulses using a counter circuit based on the output signal 86 of the photoelectric detector 28, and counts 450 mm ÷ 3 mm/ms = 150 ms or more. At this point, the clutch 41, which is a component of the supply section 1, is driven, and the suction belt 32 is operated. The suction hole of the suction belt 32 is the photoelectric detector 39.
When detected, the drive of the clutch 41 is stopped, the brake 43 is activated, and the suction belt 32 is stopped. In this way, mail can be taken out one by one. The point devices 16 to 21 are directly driven by signals from the photoelectric detectors 22 to 27, but the basic signals are driven by the photoelectric detectors 67 installed at each of the one-to-one collection points 10 to 15. controlled by When the mail is taken out from the mail collection points 10 to 15 at the request of the person who presses the key, the optical axis of the photoelectric detector 67 is made conductive, and the mail further conveyed through the loop-shaped conveyance path 3 is detected by the photoelectric detector. The moment I crossed 22-27,
The point devices 16 to 21 are set to operate.

In the mail collection stations 10 to 15, when the photoelectric detector 67 receives the mail through the branch paths 4 to 9, its optical axis is blocked, which causes the clutch brake 70 to disengage. The brake is activated, the drive rollers 66 ₁ and 66 ₂ stop rotating, and the belts 64 ₁ and 64 ₂ stop. The mail is stacked one by one while being held between the belts 64 ₁ and 64 ₂ . The brake is released in response to the key presser's request,
When the clutch operates and this mail is retrieved,
The photoelectric detector 67 makes its optical axis conductive and operates the switches 16 to 21 as described above.

The photoelectric detector 29 detects the distance between the mail items conveyed on the loop-shaped conveyance path 3 . Control unit 8
4 counts clock pulses based on the output signal of the photoelectric detector 29 and stores them in a register in the control section 84. Let this content be Xms.

Furthermore, the distance between the next mail items is determined by the photoelectric detector 29.
is detected, and the control section 84 counts the clock pulses. Let this be Yms.

The pause mechanism 30 operates when the following three conditions are all met.

(1) X≧24ms (2) Y≧257ms (3) X+Y≧174ms Then, the moment the photoelectric detector 29 finishes detecting Yms, that is, the tip of the third piece of mail blocks the photoelectric detector 29. From the moment the distance between photoelectric detector 29 and photoelectric detector 31 [mm] / 3 [mm
/ms] After the time [ms] shown in [ms] has elapsed,
The moment the photoelectric detector 31 is shielded from light, the temporary stop mechanism 30 is activated and the belts 55 and 56 are stopped. At that time, only one piece of mail to be temporarily stopped is held between the belts 55 and 56 that constitute the temporary stop mechanism 30.

The time during which belts 55 and 56 are stopped is (Y-24)ms It is.

In this way, the control as previously explained with reference to FIG. 14 is performed, and a sufficient interval for inserting one piece of mail is secured.

The value of Y is replaced with the register that had stored the value of X, and the control is repeated in response to the signal from the photoelectric detector 29.

(Effects of the Invention) As explained above, the present invention eliminates jams by stacking only one piece of mail at each coding desk's collection point by holding it between the belts. Since mail can be supplied from a short distance from a loop-shaped conveyance path, the person typing the key does not have to stop working for a long time, so the introduction of machines has substantially improved processing capacity. This has the effect of improving operability for workers.

[Brief explanation of the drawing]

FIG. 1 is an overall view of one embodiment of the mail supply device of the coding desk suite of the present invention, and FIG.
4 shows the configuration of the supply section 1, FIG. 5 shows the conveyance path 2, FIG. 6 shows the loop-shaped conveyance path 3, and FIGS.
9 and 10 are diagrams showing the configuration of the temporary stop mechanism 30, FIG. 11 is a diagram showing the input and output of the control unit 84, FIG. 12 is a diagram showing the drive current of the switch units 16 to 21, and FIG. Figure 14 is a diagram showing the flow of mail items, Figure 14 is an explanatory diagram regarding the distance between mail items, Figure 15 is an overall diagram of the conventional device, and Figure 16 is a diagram explaining envelopes that cause problems with the conventional device. , FIG. 17 is a diagram showing the state of the jam. DESCRIPTION OF SYMBOLS 1... Supply part, 2... Conveyance path, 3... Loop-shaped conveyance path, 4-9... Branch path, 10-15... Single collection place,
16-21... Switch, 22-29, 31... Photoelectric detector, 30... Temporary stop mechanism, 84... Control unit.

Claims (1)

[Scope of Claims] 1. A mail supply section, a conveyance means having one end of a conveyance path connected to the mail supply section, and a loop-shaped conveyance path connected to the other end of the conveyance path of the conveyance means. A conveying means, a plurality of branch paths provided in the loop-shaped conveyance path, a single mail accumulation mechanism provided at the end of each branch path for accumulating only one piece of mail, and mail items are accumulated in the single mail accumulation mechanism. a first photoelectric detector that detects this, and a second photoelectric detector that is installed in front of the entrance of each branch path of the loop-shaped conveyance path and detects the leading edge of the mail piece that has been conveyed through the loop-shaped conveyance path. and between the entrance of each branch path and each second photoelectric detector,
A switch provided along the loop-shaped conveyance path, and a loop-shaped point provided so that the optical axis is perpendicular to the loop-shaped conveyance path, and from the optical axis to the point where the loop-shaped conveyance path and the conveyance path intersect. The distance in the conveyance direction of the conveyance path is longer than the distance of the conveyance path from the end of the mailpiece to the point when the mailpiece is taken out by the mail supply unit by an amount that allows the mailpieces to be lined up at a minimum interval, and A third photoelectric detector detects the tip of the mail that has not been branched into the single mail stacking mechanism, and the optical axis is perpendicular to the loop-shaped conveyance path and is installed at a position upstream of the third photoelectric detector. a fourth photoelectric detector provided between the fourth photoelectric detector and the third photoelectric detector, which is part of the loop-shaped conveyance path but driven by a drive source different from that of the loop-shaped conveyance means; The first photoelectric detector detects that no mail is accumulated in the one-piece stacking mechanism, and the first photoelectric detector detects that no mail is accumulated in the one-piece accumulation mechanism. Sometimes, when the second photoelectric detector corresponding to the one-piece stacking mechanism detects the leading edge of the mail piece, the switch corresponding to the one-piece stacking mechanism is operated for a time such that only one piece of mail is separated. , when the third photoelectric detector is not blocked by the mail for a period of time corresponding to the interval at which one mail can be inserted, causes the supply unit to feed the mail, and detects the leading edge of the mail. stops the supply of mail to the supply unit, determines the two intervals between three successive pieces of mail conveyed through the loop-shaped conveyance path by the fourth photoelectric detector, and calculates the distance between these three pieces of mail. When the spacing is not large enough to insert a single piece of mail, but is too large for the person who presses the key to request the mail immediately, the pause mechanism pauses the mail that is located in the middle of three consecutive pieces of mail. A mail supply device for a coding desk suite having a control unit for ensuring that the distance between the previous two mails is at least a size that allows one mail to be inserted.