Patent Application
20070018377
This invention generally relates to machines that operate at a very high speed to insert sheets of paper or other items into envelopes. More particularly, it relates to a shuttle envelope feeder that transports the envelopes to be inserted.
Machines for automatically inserting items such as sheets of paper into envelopes are known in the art. A state-of-the-art mail inserting machine such as the Pitney Bowes Flowmaster™ FX14 can perform 12,000 insertions per hour when properly maintained and adjusted.
A typical high-speed inserting machine comprises several modules. A first module transports an elongate horizontal queue of envelopes to an envelope stack. An envelope feeder located at the bottom of the envelope stack delivers the envelopes one by one to an envelope insertion station. A second module delivers individual groups of stacked sheets to the envelope insertion station. A third module, the envelope insertion station, includes clamps carried by an elongate sprocket chain that sequentially receives envelopes from the envelope feeder and pulls them past an envelope flap-opening structure and a sheet inserting structure where the envelopes are opened and inserted with stacked sheets. The envelopes are then pulled past an envelope closing structure and an envelope sealing structure before been ejected to a collection station. envelope closing structure and an envelope sealing structure before been ejected to a collection station.
The vacuum envelope feeder of the above arrangement works well when envelopes are substantially flat. If, however, some of the envelopes are significantly curled or bent, the shuttle vacuum may not have sufficient suction to pull down these envelopes, causing a failure in the shuttle feed.
Some methods have been proposed in order to solve the above problem. One is to add pressure to the top of the envelope stack to help flatten the envelopes. This method is somewhat ineffective, because an improperly applied stack pressure can also cause a failure in the shuttle feed or multiple envelope feedings.
Another method uses a thumper to add stack pressure when the shuttle vacuum is turned on. When the shuttle moves forward, the thumper retracts and the shuttle vacuum holds the curled envelope. The disadvantages of this method are that the thumper disturbs the stack and the flow of envelopes from the envelope transport module, and it requires constant mechanical adjustment.
What is needed is a vacuum shuttle feeder that is capable of feeding curled envelopes without failure. Preferably, the operation of such feeder will not interfere with existing configuration of the envelope stack or envelope flow. In addition, the feeder should be operative over a wide range of envelope dimensions.
The invention provides an envelope feeder in an envelope insertion machine for removing envelopes from an envelope stack. The envelope feeder comprises a shuttle plate and a suction cup assembly.
The shuttle plate is operable between a first position under the envelope stack and a second position at least partially remote from the envelope stack. The shuttle plate has an orifice passing through its upper surface, and an envelope gripping mechanism that is in communication with a shuttle vacuum valve.
The suction cup assembly comprises a suction cup that has an upper rim and a lower neck with an opening formed therein, the opening is connected to a hollow rod. The rod, in turn, is in communication with a suction cup vacuum valve. An actuator engages the suction cup and moves the suction cup between an extended position that passes through the orifice in the shuttle plate to a retracted position that the upper rim of the suction cup is at least flush with the upper surface of the shuttle plate.
The suction cup vacuum valve is activated at least when the suction cup is in the extended position so that the suction cup attaches to an envelope at the bottom of the envelope stack. The suction cup pulls the envelope toward the upper surface of the shuttle plate as the actuator moves from the extended position to the retracted position.
The shuttle vacuum valve is activated at least when the envelope is pulled toward the upper surface of the shuttle plate. By doing so, the envelope is retained by the envelope gripping mechanism, allowing the shuttle plate to remove the envelope from the envelope stack as the shuttle plate moves to its second position.
The invention further provides a method for an above-described envelope feeder in an envelope insertion machine to remove an envelope from an envelope stack. The method comprising the steps of: placing the shuttle plate in the first position, moving the suction cup between the retracted position that is at least flush with the upper surface of the shuttle plate and the extended position that is in contact with an envelope at the bottom of the envelope stack, and controlling the air pressure within the suction cup so that the suction cup has a lower air pressure than the ambient air pressure when the suction cup is in the extended position and while it moves from the extended position to the retracted position.
In accordance with the method, the envelope at the bottom of the envelope stack is pulled down toward the upper surface of the shuttle plate so as to facilitate the acquisition of said envelope by the envelope gripping mechanism.
The above and other objects, features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with accompanying drawings, in which:
Referring to
Referring now to
The suction cup 230 is thus in cooperative engagement with an actuator or air cylinder 236, which, in turn, is in communication with an air cylinder valve 262 (seen in
Referring further to
With the shuttle plate 150 at the first position and the trailing edge of the previous envelope off of the suction cup 230, the actuator 236 moves the cup 230 toward the extended position and the suction cup vacuum valve 238 is activated (vacuum ON). Once the suction cup 230 reaches the extended position, a small time delay is used to insure that the suction cup 230 attaches to an envelope at the bottom of the envelope stack. The actuator then pulls the suction cup 230 toward the retracted position.
Once the suction cup 230 reaches the retracted position, the shuttle vacuum valve 256 is activated to allow the envelope gripping mechanism 180 to acquire the envelope. The suction cup vacuum valve can be deactivated (turned OFF) immediately after envelope is acquired. The shuttle plate 150 then moves toward the second position with the envelope going under a stripper bar 170 so that it is separated from the remaining envelopes in the envelope stack. After clamps 190 (see
The computer 300 stores parameters such as the real-time shuttle position acquired via a position circuit with an position encoder or resolver 330 having a position sensor 331, envelope width, the distance D between the leading edge 254 of the shuttle plate and the center of the suction cup 230, air valve latencies, air cylinder latencies and system latencies. Based on the parameters pre-stored in the computer and acquired by the computer, the computer calculates a time sequence for actuating the suction cup and activating/deactivating the suction cup vacuum valve for the input/output control module 310 to coordinate the operation of the valves. The specific computer programming and controlling procedures of vacuum and air valves according to such specific parameters is known to people of ordinary skills in the art.
First Embodiment of the Invention
In a first embodiment of the invention as shown in
Second Embodiment of the Invention
In a second embodiment of the invention as shown in
Third and Preferred Embodiment of the Invention
In a third and preferred embodiment of the invention as shown in
The first orifice 240 is dimensioned larger than the outer dimension of the first suction cup 230 so as to allow the first suction cup to reside inside the orifice when the first suction cup is in the retracted position. The second orifice 440 is in elongated shape and is dimensioned larger than the outer dimension of the second suction cup 430. The second suction cup 430 resides inside the second orifice 440 when the second suction cup is in the retracted position, and the second suction cup is not in obstruction with the movement of the shuttle plate.
As shown in
A computer 300 (or other programmable logical device) stores parameters such as the real-time shuttle position acquired via a up/down counter 320 in communication with a position encoder 330 having a position sensor 331, envelope width, the distance D between the leading edge 254 of the shuttle plate 150 to the center of the first suction cup 230, air valve latencies, air cylinder latencies and system latencies. Based on the parameters pre-stored in the computer and acquired by the computer, the computer calculates a time sequence for actuating the suction cups and activating/deactivating the suction cup vacuum valves for the input/output control module 310′ to coordinate the operation of the valves.
Alternative Embodiments of the Invention
The vacuum suction mechanism of present invention may be replaced by other 15 mechanisms that temporarily acquire envelope through a moving part that is in corporation with the shuttle plate. Examples include a receiving member in place of the suction cup that is charged with static electrons. The static electrons attract the envelope at the bottom of the envelope stack when the receiving member is in close proximity of the envelope. Thereby temporarily secure the envelope onto the receiving member.
In summary, the present invention relates to a shuttle envelope feeder with a vacuum suction cup assist mechanism. The present invention has the advantage of acquiring cupped or bent envelopes in an envelope stack in a very repeatable fashion. The suction cup controlling mechanism is separable from the controlling mechanism of the shuttle plate. One or more suction cups can be individually enabled or disabled according to the conditions of the envelopes in the envelope stack.
Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein without departing from the spirit and scope of the present invention.
