1-8. (canceled)
9. An apparatus for separating flat mail items, comprising:
two transportation devices for transporting a first stack of mail items and a second stack of mail items movable independently of one another;
a singulating device for pulling mail items from the first stack and the second stack of mail items and feeding the mail items into a transportation path, said singulating device having a integrally formed pulling element for pulling mail items from the first stack and the second stack of mail items;
a retaining device for selectively feeding mail items from either the first or the second stack of mail items to said pulling element, said retaining device having first and second retaining elements for retaining mail items from the first stack of mail items or the second stack of mail items, respectively; and
a drive configured to move said first and second retaining elements in a synchronized manner such that a retaining movement of said first retaining element is coupled with a release movement of said second retaining element.
10. The apparatus according to claim 9, wherein the two transportation devices are adapted for transporting the first stack and the second stack of mail items from mutually different directions to said pulling element.
11. The apparatus according to claim 9, wherein said pulling element is mounted such that it can be moved in two directions being inverse to each other.
12. The apparatus according to claim 9, wherein said pulling element has a first extraction area with a first direction of motion and a second extraction area with a second direction of motion opposite the first direction, and wherein the transportation devices are adapted for transporting the first stack of mail items to the first pulling area and the transporting the second stack of mail items to the second pulling area.
13. The apparatus according to claim 9, which comprises a sucking device for sucking the mail items from the first and second stacks of mail items the sucking device being disposed inside an area circumscribed by said pulling element.
14. The apparatus according to claim 13, wherein a suction direction of said sucking device can be switched over.
15. The apparatus according to claim 9, which further comprises a control unit for controlling a movement of said pulling element in such a manner that between two consecutive mail items from different stacks the same distance is set than between two consecutive mail items from the same stack.
16. The apparatus according to claim 9, wherein said retaining elements carry sensors for outputting signals which are usable for controlling a movement of the first and second stacks of mail items.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A flow measurement device, comprising:
a wave guide tube type resonant cavity;
a penetrating space that penetrates the resonant cavity;
a duct support part that is made of a dielectric substance, is in the resonant cavity and surrounds an outside of the penetrating space;
a transmitting antenna that transmits a microwave transmitting to a direction along a longitudinal axial direction of the resonant cavity to provide a standing wave or a traveling wave of the microwave, the microwave is transmitted in a space that is outside of duct support part and inside of the resonant cavity; and
a receiving antenna that receives the standing wave or the traveling wave.
2. A flow measurement device as set forth in claim 1, further comprising:
a metal cylinder that protrudes to outside from an opening of the penetrating space of the resonant cavity and has an opening diameter smaller than an inner diameter of the resonant cavity.
3. A flow measurement device as set forth in claim 1, wherein:
the resonant cavity is formed in separable so that entire of the penetrating space can be exposed.
4. A flow measurement device as set forth in claim 1, wherein:
the standing wave is provided in the resonant cavity; and
the flow measurement device calculates a flow velocity of a dielectric fluid flowing in the penetrating space based on a frequency of an alternate current component of a received electric power received by the receiving antenna.
5. A flow measurement device as set forth in claim 1, wherein:
the standing wave is provided in the resonant cavity; and
the flow measurement device calculates a volume of a dielectric fluid flowing in the penetrating space based on a amplitude of an alternate current component of a received electric power received by the receiving antenna.
6. A flow measurement device as set forth in claim 5, wherein:
the flow measurement device modifies the volume based on a direct current component of the received electric power received by the receiving antenna when the volume is calculated.
7. A flow measurement device as set forth in claim 1, wherein:
the traveling wave is provided in the resonant cavity; and
the flow measurement device calculates a flow velocity of a dielectric fluid flowing in the penetrating space based on a Doppler frequency of the microwave received by the receiving antenna.