Abstract:
A method and apparatus for adjusting the position of an envelope stopper in an envelope inserting area of a mail insertion machine. By placing an envelope of a desirable size at a desired location in the envelope inserting area and using one or more fingers to sense the edge of the envelope. When the fingers are moved from the upstream end towards the downstream end, they are supported the envelope before they are moved past the edge of the envelope. As the fingers are moved past the edge of the envelope towards the downstream end, they are allowed to drop into a gap thereby changing the position of the fingers. A photosensing device is coupled to the fingers to sense the change of the position of the fingers.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to an envelope insertion machine and, more particularly, to a mechanism to place an envelope in the envelope inserting area of the envelope insertion machine. 
   BACKGROUND OF THE INVENTION 
   In a mail insertion machine, there is an envelope feeder on one end of the machine to sequentially release envelopes into an envelope inserting area. On the other end of the mail insertion machine, there is a gathering section where enclosure material is released and gathered. If the enclosure material contains a number of documents, the documents are separately released from a plurality of enclosure feeders. The released documents are then collated into a stack to be moved into the envelope inserting area where the document stack is inserted into the envelope. Envelopes can be fed from below the envelope inserting area by a lower envelope transport system. Usually, the flap of each envelope is flipped away from the throat of the envelope as the envelope is transported from the envelope feeder toward the envelope inserting area. 
   Mail insertion machines are well known. For example, U.S. Pat. No. 4,501,417 (Foster et al.) discloses an inserter feeder assembly for feeding enclosures; U.S. Pat. No. 4,753,429 (Irvine et al.) discloses a collating station; and U.S. Pat. No. 5,660,030 (Auerbach et al.) discloses an envelope inserting station wherein envelopes are separately provided to an envelope supporting deck where envelopes are spread open in order to allow enclosure material to be stuffed into the envelopes. 
   In a typical mail insertion machine, only one envelope is placed in the envelope inserting area at anytime to receive enclosure material. When the envelope is placed in the envelope inserting area and its flap is flipped away from the throat, the throat is spread open by a vacuum-suction device or by a set of mechanical fingers. As the envelope is fed from the envelope feeder from the upstream end of the inserting area, it is stopped by an envelope stopper so that the envelope is consistently placed at a desirable position for mail insertion. Typically, the vacuum-suction device or the mechanical fingers are fixedly located in the inserting area. Thus, the position of the envelope stopper must be adjusted in accordance with the length or size of the envelope. 
   It is desirable and advantageous to provide a method and an apparatus for adjusting the position of the envelope stopper according the size of the envelope in a simple yet precise manner. 
   SUMMARY OF THE INVENTION 
   The first aspect of the present invention is an apparatus for adjusting the position of an envelope stopper in an inserting area of an envelope insertion machine, wherein the inserting area has an upstream end and an downstream end, and the envelope stopper is positioned between the upstream end and the downstream end, for stopping an envelope fed from the upstream end towards the downstream end along a feeding direction, in order to place the envelope at a desired location for mail insertion, and wherein the envelope has a size and an edge, and the position of the envelope stopper is adjusted according to the size of the envelope, so that the edge of the envelope is substantially aligned with the envelope stopper when the envelope is stopped. The apparatus comprises: 
   a sensing device, coupled to the envelope stopper, adapted to sense the edge of the envelope when the envelope is placed at the desired location; and 
   a mechanism, for moving the sensing device and the envelope stopper along the feeding direction and for placing the envelope stopper when the sensing device senses the edge of the envelope. 
   Preferably, the envelope stopper has a stop edge which is capable of operating at a first position and a second position, and wherein the envelope stopper is capable of stopping the envelope fed from the upstream end with the stop edge when the stop edge is operated at the first position; and the envelope stopper allows the envelope fed from the upstream to pass by the envelope stopper when the stop edge is operated at the second position, and wherein the stop edge is operated at the second position when the envelope stopper is moved by the moving means along the feeding direction in order to adjust the position of the envelope stopper. 
   Preferably, the sensing device comprises a photosensing device which is adapted to produce a signal when the sensing device senses the edge of the envelope so as to allow the moving means to place the envelope stopper in response to the signal. 
   Preferably, the sensing device further comprises at least one mechanical finger pivotally mount on the sensing device, wherein the mechanical finger is positioned at a first level, supported by the envelope, when the envelope stopper is away from the edge of the envelope and further away from the downstream end, and wherein the mechanical finger is positioned at a second level when the envelope stopper is away from the edge of the envelope and further away from the upstream end, and wherein the photosensor device produces the signal when the position of the mechanical finger is changed from the first level to the second level, or from the second level to the first level. 
   Preferably, the photosensing device comprises a pair of photosensors and the finger is coupled to a blocking mechanism such that the photosensors are blocked by the blocking mechanism at a blocking position when the finger is positioned at the first level, and the blocking mechanism is removed from the blocking position when the finger is positioned at the second level. 
   Preferably, the photosensors are separately mounted on a mounting device having a gap separating the photosensors, and wherein the blocking mechanism includes a blade capable of moving into the gap to the blocking position to block the photosensors when the finger is positioned at the first level. 
   Preferably, the envelope is supported by a plurality of endless belts in the inserting area, and the endless belts define a recess therebetween, and wherein the finger is capable of moving into the recess to be positioned at the second level. 
   The second aspect of the present invention is a method for adjusting the position of an envelope stopper in an inserting area of an envelope insertion machine, wherein the envelope stopper is positioned between the upstream end and the downstream end, according to the size of the envelope, for stopping an envelope fed from the upstream end towards the downstream end along a feeding direction, in order to place the envelope for mail insertion. The method comprises the steps of: 
   placing the envelope at a desired location; 
   providing a sensing device capable of sensing the edge of the envelope; 
   moving the sensing device and the envelope stopper along the feeding direction; and 
   interrupting the movement of the envelope stopper when the sensing device senses the edge of the envelope, wherein the sensing device is coupled to the envelope stopper so that the edge of the envelope is substantially aligned with the envelope stopper when the sensing device senses the edge of the envelope. 
   Preferably, the sensing device is capable of providing a signal when the sensing device senses the edge of the envelope and the movement of the envelope stopper is interrupted in response to the signal. 
   Preferably, the sensing device comprises at least one mechanical finger pivotally mount on the sensing device, wherein the mechanical finger is positioned at a first level, supported by the envelope, when the envelope stopper is away from the edge of the envelope and further away from the downstream end, and wherein the mechanical finger is positioned at a second level when the envelope stopper is away from the edge of the envelope and further away from the upstream end, and wherein the signal is produced when the position of the mechanical finger is changed from the second level to the first level, or from the first level to the second level. 
   Preferably, the sensing devices further comprises a photosensing device, and the mechanical finger is coupled to a blocking mechanism, and wherein the blocking mechanism is capable of blocking the photosensing device at a blocking position when the finger is positioned at the first level, and the block mechanism is removed from the blocking position when the finger is positioned at the second level, and wherein the photosensing device produces the signal when the blocking device is removed from the blocking position, or when the blocking device moves into the blocking position. 
   The present invention will become apparent upon reading the description taken in conjunction with  FIGS. 1  to  7 B. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing part of a mail insertion machine. 
       FIG. 2  is a diagrammatic representation illustrating a lower envelope transport connecting an envelope feeder to the envelope inserting area. 
       FIG. 3A  is a diagrammatic representation illustrating an envelope stopper assembly at one position. 
       FIG. 3B  is a diagrammatic representation illustrating the envelope stopper assembly at another position. 
       FIG. 4A  is a diagrammatic representation illustrating the envelope sensing assembly of the present invention being positioned away from the bottom edge of an envelope, and further away from the downstream end. 
       FIG. 4B  is a diagrammatic representation illustrating the envelope sensing assembly being positioned at the bottom edge of the envelope. 
       FIG. 5A  is a side view of the envelope edge sensing device, according to the present invention. 
       FIG. 5B  is a top view of the envelope edge sensing device. 
       FIG. 5C  is a front view of the envelope edge sensing device. 
       FIG. 6  is a diagrammatic representation illustrating a belt transport assembly, which supports the envelope in the envelope inserting area. 
       FIG. 7A  is a diagrammatic representation illustrating the position of a sensor lever when the envelope sensing assembly is positioned away from the bottom edge of the envelope. 
       FIG. 7B  is a diagrammatic representation illustrating the position of the sensor lever when the envelope sensing assembly is positioned at the bottom edge of the envelope. 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows part of a typical mail insertion machine  10 . As shown in  FIG. 1 , the mail insertion machine  10  has a gathering section (not shown) where enclosure material is gathered and collated into a stack to be moved into an envelope inserting area  12 . As shown, an envelope  100  is placed in the envelope inserting area  12  to receive enclosure material (see  FIG. 2 ) from the gathering section. The envelope  100  is fed from a feeder, part of which is denoted by numeral  18 . 
     FIG. 2  shows part of a lower transport  110  for moving envelopes from the envelope feeder  18  ( FIG. 1 ) towards the envelope inserting area  12 . In this particular mail insertion machine, there are two channels  20 ,  22  for alternately moving one envelope at a time by a plurality of rollers  30  from the envelope feeder  18  through a common channel  24  towards the envelope inserting area  12 . The envelope  100  is moved into and located in the envelope inserting area  12  by a belt transport assembly  16 , which includes rollers  32 ,  34  and an endless belt  50 . As shown in  FIG. 2 , the envelope  100  located in the envelope inserting area  12  has a bottom edge  102 , and a throat  104  adjoining a flap  108 . The flap  108  of the envelope  100  is flipped away from the throat  104 . The bottom edge  102  of the envelope  100  is stopped by one of stop edges  42  of an envelope stopper  40 , so that the throat  104  of the envelope  100  is positioned at an insertion point  98 , where the throat  104  of the envelope  100  is spread open for mail insertion. As shown in  FIG. 2 , a stack of enclosure material  120  is pushed by a pusher finger  124  from the upstream end  112  through a pair of enclosure material guides  130  into the envelope  100 . It is important to set a correct distance D between the insertion point  98  and the pusher finger  124  so that the enclosure material  120  can be properly inserted into the envelope  100 . Furthermore, the mail insertion machine  10  can be used with envelopes of different sizes and, therefore, the location of the envelope stopper  40  must be adjusted according the size of the envelope  100 . Thus, the distance S between the stop edge  42  of the envelope stopper  40  and the insertion point  98  must be adjusted so that the throat  104  of the envelope  100  is substantially located at the insertion point  98 . 
   The envelope stopper  40  is pivotally mounted at a pivot point  140 . The envelope stopper  40  can be operated at a first position to stop an envelope coming from the upstream end  112 , and a second position to allow an envelope to move to the downstream end  114 . In  FIG. 2 , the first position of the envelope stopper  40  is shown in solid lines and the second position is shown in dashed lines. After the enclosure material  120  is inserted into the envelope  100 , the stuffed envelope (not shown) is moved towards to downstream end  114  by the belt transport assembly  16  and an exit roller  36 . At the same time, the envelope stopper  40  is rotated  90  degrees about the pivot point  140  to the second position (see  FIGS. 3A and 3B ) so that the stop edge  42  is moved out of the way of the stuffed envelope. 
   When a stack of envelopes with a different size is used for mail insertion, the location of envelope stopper  40  must be adjusted accordingly.  FIGS. 3A and 3B  illustrates an envelope stopper assembly  14  for relocating the envelope stopper  40 . The envelope stopper assembly  14  includes an envelope sensing assembly  160  which is coupled to the envelope stopper  40  by a coupling mechanism  200  so that the relative position of the envelope stopper  40  and the envelope sensing assembly is fixed. The coupling mechanism  200  can be a mechanical linkage or an electrical linkage using one or more servo motors to position the envelope stopper  40 . The envelope stopper assembly  14  can be moved along an X direction to simultaneously relocate the envelope sensing assembly  160  and the envelope stopper  40 , along with the exit roller  36 . During the relocation of the envelope stopper  40 , the envelope stopper  40  is operated at the second position, so that the stop edge  42  does not interfere with the envelope  100  which is placed at a desirable position where the throat  104  is substantially located at the insertion point  98 . The envelope sensing assembly  160  includes an edge sensing device  60 . As shown in  FIGS. 3A and 3B , the edge sensing device  60  has a plurality of fingers  68  (see  FIGS. 5B and 5C ) which can sense the presence of an envelope placed on the belt  50 . The fingers  68  are pivotally mount at pivot  162  so that their position, relative to the surface  150  (see  FIGS. 4A and 4B ) of the belt  50 , can change. As shown in  FIG. 3A , the fingers  68  are supported by the envelope  100  and, therefore, the position of the fingers are above the surface of the belt  50 . As shown in  FIG. 3B , the position of the fingers are dropped below the surface of the belt  50  when the fingers are not supported by the envelope  100 . Thus, by moving the envelope stopper assembly  14  along the X direction, it is possible to sense the bottom edge  102  of the envelope  100  by monitoring the position of the fingers  68 , relative to the surface of the belt  50 . Accordingly, the bottom edge  102  can be sensed by the transition of the position of the fingers  68 , as shown in  FIG. 3A , to the position of the fingers  68 , as shown in FIG.  3 B. The relative position of the envelope stopper.  40  to the fingers  68  is set so that when the fingers  68  senses the transition from being supported by the bottom edge  102  to being not supported by the bottom edge  102 , the bottom edge  102  is substantially aligned with the stop edge  42  if the envelope stopper  40  is operated at the first position (see FIG.  2 ). 
     FIGS. 4A and 4B  illustrate the edge sensing device  60  being coupled to a photosensor assembly  80 . Each of the fingers  68  is attached to a sensor lever  66  which is connected to an sensor arm  64  to be pivotally mounted at pivot  162 . The sensor lever  66  is linked to a blade  70 . The photosensor assembly  80  includes a pair of photosensors  74 ,  76  mounted on a photosensor mount  72 . As shown in  FIG. 4A , when the fingers  68  are supported by the envelope  100 , they are positioned above the surface  150 , and the blade  70  is in a Ablocking≅position (see  FIG. 7A ) for blocking the photosensors  74 ,  76 . As shown in  FIG. 4B , when the fingers  68  are not supported by the envelope  100 , they are position below the surface  150 , and the blade  70  is in a Anon-blocking≅position (see FIG.  7 B), allowing the photosensors  74 ,  76  to function. Thus, the photosensors  74 ,  76  can be used to produce a signal when the fingers  68  just pass the bottom edge  102  of the envelope  100  while the envelope sensing assembly is moved from the upstream end  112  towards the downstream end  114 . As shown in  FIGS. 4A and 4B , the photosensor mount  72  is attached to a mounting arm  88  connected to a mounting plate  82 . The mounting plate  82  has two slots  86  fitted to two stop pins  84  so as to allow the adjustment of the relative position of the photosensors  74 ,  76  to the blade  70  for fine-tuning the stopping position by the stop edge  42 . 
     FIGS. 5A-5C  illustrates the different views of the edge sensing device  60 . As shown, the edge sensing device  60  has two fingers  68 , each is part of a sensor lever  66 , connected by a connecting plate  62 . The blade  70  is rigidly mounted on the connecting plate  62 , so that the blade  70  is moved about the pivot point  162  (see  FIGS. 4A and 4B ) together with the fingers  68 . 
     FIG. 6  illustrates the belt transport assembly  16 , which includes three belts  50  driven by six rollers  32 . As shown, there is a gap  54  between two adjacent belts  50  so as to allow the fingers  68  to drop into the gap  54  when the fingers  68  are not supported by the envelope  100 , as shown in FIG.  7 B. 
   As shown in  FIGS. 7A and 7B , each of the belts  50  is supported by a belt guide  52 . The upper loop of each belt  50  is located on the surface  150 . The photosensors  74 ,  76  are separately mounted on the photosensor mount  72 , separated by a gap  78 . When the fingers  68  are supported by the envelope  100  (see  FIG. 4A ) and positioned above the surface  150 , the blade  70  is positioned deep inside the gap  78 , thereby blocking the photosensor pairs  74 ,  76 , as shown in FIG.  7 A. However, when the fingers  68  are not supported by the envelope  100  (see  FIG. 4B ) and positioned below the surface  150 , the blade  70  is retreated outward from the gap  78  and away from the blocking position, as shown in FIG.  7 B. It is understood that the photosensors  74 ,  76  include a photoemitter and a photo transistor or diode which is capable to produce a signal indicating the reception of light from the photoemitter. Photosensors are well-known in the art. 
   It should be noted that the adjustment of the envelope stopper  40  can be carried out manually by an operator who places the envelope  100  at the desirable position and, preferably, moves the envelope sensing assembly from the upstream end  112  towards the downstream end  114 . The operator sets the envelope stopper  40  in place upon seeing a signal produced by the photosensors  74 ,  76 , indicating that the fingers  68  just pass the bottom edge  68  of the envelope  100 . Alternately, the adjustment of the envelope stopper  40  can be carried out by a moving device which is stopped in response to the signal produced by the photosensors  74 ,  76 . 
   It should be noted that the blade  70  can be positioned differently so that the photosensors  74 ,  76  are blocked when the fingers are not supported by the envelope  100  and the photosensors  74 ,  76  are not blocked when the fingers are supported by the envelope  100 . 
   Furthermore, while it is preferred to place an envelope at the desired location in the inserting area in order to adjust the position of the envelope stopper, it is possible to use an object having a length representative the size of the envelope to replace the envelope. Thus, the reference numeral  100 , as shown in  FIGS. 3A  to  4 B, can be used to denote the replacement object for adjustment purposes. 
   Thus, although the invention has been described with respect to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and various other changes, omissions and deviations in the form and detail thereof may be made without departing from the spirit and scope of this invention.