Sheet feeding or delivering – Feeding – Pack holders
Reexamination Certificate
1998-08-28
2001-01-30
Walsh, Donald P. (Department: 3653)
Sheet feeding or delivering
Feeding
Pack holders
C271S152000, C271S154000, C271S157000, C271S162000, C271S003010, C271S003120, C271S003130
Reexamination Certificate
active
06179283
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a method for controlling an intermediate stacking device of flat shipments, in particular in letter sorting facilities, which comprises a stacking device positioned on a movable stacking cart, a bottom transport belt on which the shipments are positioned crosswise to the belt movement direction, and a separating device having a withdrawal means as well as a shipment sensor for detecting the shipments at the separating device.
Intermediate stacking devices are used, for example, in letter sorting facilities to connect different structural components. The intermediate stacking device in this case buffers the irregularly arriving shipments, so that the following structural components are stressed relatively evenly.
The DE-AS 12 35 818 discloses a device for stacking shipments, in particular postal shipments, with the aid of a stacking roller, arranged on a stacking cart. The device furthermore comprises a bottom transporting belt, a separating device, spring-mounted elements for stopping the shipments at the stacking wall and to prevent a rebounding from the stacking wall, as well as a switch that controls the forward and backward movements of the stacking cart in dependence on the pressure exerted by the stack leaning against it.
In a known intermediate stacking device, the individual shipments to be stacked, which are clamped between a front belt and a rear belt, are conveyed close to the stacking location where a stack of shipments already exists or is being formed with the shipments to be stacked. The stack is formed by conveying the shipments individually, one after another, with their front edge to a stacking wall. For this, the front belt is removed from the shipment at a certain distance from the stacking wall. Owing to its mass moment of inertia, the shipment continues to move along a guide rail in the direction of the stacking wall. Finally, the shipment is conveyed by the rotating stacking roller into the space between the shipment stack and the stacking roller and is conveyed further until it reaches the stacking wall.
The shipments in the shipment stack are positioned with their lower edges on a bottom transport belt, crosswise to its movement direction, which belt can be moved along the stacking wall. A separating device is provided on the stack side opposite the stacking roller, which can withdraw the shipments one after another from the stack of shipments for further processing.
The bottom transport belt is moved in the direction of the separating device such that the stack leans against the separating device, and the shipment closest to the separating device can be withdrawn. In the stacking region, the stacking roller must be positioned such that the shipments to be stacked can be conveyed without problems between the stacking roller and the stack to the stacking wall. A device for measuring the stack pressure is provided for this near the stacking roller, and a device for detecting possible slanted positions of the shipment stack is provided at the stacking location. The stacking cart is moved along the bottom transport belt until the shipment stack exerts a specific pressure upon the pressure measuring device, provided the device does not signal a slanted position. If a slanted position has been detected at the stacking location, the stacking cart and/or the bottom transport belt are moved until the slanted position has been corrected.
The “migration” of the stack from the stacking location to the withdrawal location is made possible by the bottom transport belt on which the stack rests. Inside the withdrawal device, this bottom transport belt is controlled by sensing levers functioning as shipment sensors. If these sensing levers are disengaged, meaning if they signal that no shipment is present at the withdrawal means for the separating device, then the complete stack is moved forward by means of the bottom transport belt until the sensing levers are no longer disengaged.
The use of a friction/suction separating device according to the DE-PS 43 13 150 has the advantage of providing a better withdrawal gap stability, as long as the shipment stack rests solidly against the withdrawal means. However, by suctioning in the shipment that is respectively in front, the sensing levers are depressed even if the stack behind it has already become loose. Thus, this situation cannot be detected by means of the standard bottom-transport belt controls, and the stack cannot be made to follow continuously. As a result, the stack loosens even further and becomes slanted until the suction pressure is no longer sufficient to withdraw the shipment in front. Depending on the condition of the shipment, the subsequent bottom transport belt movement in most cases cannot correct the slanted position. In the final effect, the gaps increase and the throughput decreases.
It is thus the object of the invention to create a method for intermediate stacking devices of the type originally described, which method is designed to correct the slanted positions of the shipment stack at the separating device without causing any disturbance and without requiring additional devices.
The method includes a limit value for the time interval during which no shipment is present at the withdrawal means, which interval is the starting point for detecting a slanted stack position. The duration of the stack compression depends on the stack thickness. This is designed to avoid the effect that if the stack is compressed for too short a time, the compressing has no effect and if the stack is compressed for too long a time, the shipments or machines will be damaged.
Advantageous embodiments and modification of the invention are described and claimed.
REFERENCES:
patent: 483480B (1975-02-01), None
patent: 1235818 (1967-03-01), None
patent: 195 47 292 A1 (1997-06-01), None
Gerstenberg Frank
Kuehnapfel Joachim
Obier Gerhard
Schererz Holger
Kunitz Norman N.
Miller Jonathan R
Siemens Aktiengesellschaft
Venable
Walsh Donald P.
LandOfFree
Method for controlling an intermediate stacking device for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for controlling an intermediate stacking device for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for controlling an intermediate stacking device for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2482678