1. Field of the Invention
The present invention relates to a method and an apparatus of inserting insert or enclosure material such as sheets of document, booklet and the like into an envelope which is made of paper, plastic film or any other appropriate materials. More specifically, the invention relates to envelope inserting method and apparatus which makes possible improvement in the envelope inserting efficiency by permitting the insert material to flow in a continuous, streamlined manner.
Envelopes are available in various shapes and sizes, including oblong-shaped envelopes having a flap portion on the longer side or the shorter side thereof, envelops with predetermined sizes prescribed by the post office and various sizes determined according to the content document sizes such as international A5, A4 and A3 sizes, and various DL envelopes with an outlook window.
The present invention is applicable not only to such envelopes of various shapes and sizes, but also to various forms of contents to be inserted or enclosed in the envelopes, including a plurality of cut sheets laid in a bundle, insert material folded in half, third or fourth, brochure or books saddle stitched or perfect bound and collated insert material. It is noted that in this specification these enclosure contents to be inserted into envelopes are generally referred to as xe2x80x9cinsert material.xe2x80x9d As is apparent in the art, after the insert material has been inserted, the envelope is closed and sealed by its flap. The present invention is directed to the method and apparatus of envelope inserting which is performed preceding such flap closing and sealing process.
2. Description of the Related Art
For better understanding to the background underlying the present invention, reference is made to FIG. 2 which shows a typical known method of envelope inserting. As seen in the drawing, insert material 1 is being inserted as indicated by arrow 3 into an envelope 2 which is then located at envelope inserting position through an opened throat of the envelope. A preceding envelope 2a having the insert material 1 already inserted therein is transferred in the direction of arrow 3a and a succeeding empty envelope 2b is transferred toward the envelope inserting position as indicated by arrow 3b. 
As would be appreciated from the drawing, the conventional envelope inserting method is characterized in that all operations involved with the envelope inserting, including insertion of the insert material 1 and the transferring of envelopes 2, 2a, 2b, are performed in a horizontal plane. Another feature of the prior art method resides in the change of moving direction of the insert material 1. That is, the insert material 1 is moved in the arrow direction 3 to be inserted into the envelope 2, while the insert material 1 thus inserted into the envelope is then moved in the direction 3a that is perpendicular to the inserting direction 3.
The distance for which the insert material 1 must be moved for insertion into the envelope 2 generally depends on the size of the envelope as measured in the arrow direction 3. Accordingly, longer time is required for the insert material 1 to be inserted completely with an increase of the above size of the envelope. An attempt may be made to design an apparatus which can speed up the envelope inserting operation, although this will only invite complication and hence higher cost of the apparatus.
On the other hand, the change of moving direction of the insert material 1 means that insert material 1 and the envelop receiving such material must make a temporary stop before the insert material 1 changes the direction of its movement. If a number of successive sets of insert material 1 is fed continuously toward the envelope inserting position at a predetermined speed, any two successive or adjacent sets of insert material 1 must be fed at a sufficiently spaced interval. This will inevitably limit the envelope inserting operation speed, thus making it difficult to achieve today""s need for high-speed envelope stuffing operation.
Therefore, it is an object of the present invention to provide a method of envelope inserting which is operable at a rate exceeding what has been achievable by conventional methods by allowing the envelopes and the insert material to move in a rational manner.
It is another object of the invention to provide an apparatus for practicing the this envelope inserting method.
To achieve the objects of the invention, the invention provides an envelope inserting method wherein the insert material is conveyed along a straight path successively to an envelope inserting position where the insert material is inserted into the envelope and the stuffed envelope is then conveyed out of the inserting position in the same direction as the above straight path. For this purpose, the method of the invention includes providing immediately above the envelope inserting position an envelope storage station where a plurality of envelopes are stored in a stack one above another with the front panel of each of the envelopes facing upward so that the envelopes in the storage station are fed successively to the envelope inserting position for insertion thereinto of insert material.
In the preferred embodiment of the invention, feeding of the envelopes is performed by means of a vertically disposed rotatable screw-like spiral member located at the downstream side of the envelope storage station as seen in the direction in which the insert material is conveyed. The spiral member has formed in the periphery thereof a spiral groove for receiving therein the bottom edges of the respective envelopes, thereby holding such envelops at the bottom edges thereof such that the bottom edges are separated one from another. The spiral member is rotatable in such a direction that causes the bottom edges of the envelopes to move downwards with the rotation of the spiral member and then to be released successively from the holding by the spiral member.
According to this method, each empty envelope has to move only for an extremely short distance to the envelope inserting position and the insert material does not have to change its direction of movement after it has been inserted into an envelope, with the result that the flow of the insert material can be streamlined and very smooth and, therefore, a remarkable speedup and improvement in the envelope inserting efficiency can be achieved.
The spiral member as the envelope feeding means can also serve to hold the envelope at its bottom edge in the envelope storage station, so that the lowermost envelope in the storage station which is subjected to frictional contact with the stuffed envelope then moving away from the envelope inserting position can be prevented from being dragged and dislocated by the movement of the stuffed envelope.
The present invention also provides an envelope inserting apparatus which comprises conveyer means for conveying the insert material along a straight path toward an envelope inserting position of the apparatus where the insert material is inserted by the conveyer means into the envelope through an opened throat and then conveying the stuffed envelope out of the envelope inserting position along the same straight path, an envelope storage station provided immediately above the envelope inserting position for storing a plurality of empty envelopes in a stack one above another with the front panel of each of the envelopes facing upwards, and throat opening means disposed adjacent to the upstream side of the envelope storage station, as viewed in the direction in which the insert material is conveyed, and operable to be brought into contact with the throat portion of envelope for opening the throat of that envelope. The envelope storage station is defined on the upstream side thereof by a flap guide member for guiding the flap portions of the envelopes and on the opposite downstream side by envelope feed means for feeding the envelopes successively to the envelope inserting position.
The conveyer means include a pushing member which is adapted to be brought into engagement with the trailing end of the insert material to push the material forward into the envelope and then into engagement with the throat portion of the rear panel of the envelope thereby to push the envelope out of the envelope inserting position along the above straight path. The envelope feed means is provided by a vertically disposed rotatable spiral member of the same structure and operable in the same manner as described in the above with reference to the envelope inserting method. The envelope inserting apparatus thus constructed can offer the above-described features and advantages.
Thus, the envelope inserting method and apparatus according to the invention can make possible remarkable improvement in working efficiency, thereby contributing greatly to fulfillment of today""s demand for further speedup in operation and the economy of the related industry.
The above and other objects, features and advantages of the invention will become apparent to those skilled in the art from the following description of preferred embodiments of the envelope inserting method and apparatus according to the present invention, which description will be made with reference to the accompanying drawings, wherein: