Abstract:
A method and system for transporting envelopes from an envelope feeder to an envelope staging area in an envelope insertion machine. The envelope transport system includes two envelope bins and two envelope supply paths linking the envelope bins to an envelope feeder. Each of the bins is used to temporarily store an envelope before that envelope is moved to the staging area. The envelope supply paths are controlled by a flipper gate which alternately opens one path and closes another so as to allow an envelope to enter one envelope bin while another envelope in the other envelope bin is moved to the staging area. With the dual envelope bins connected to the dual supply paths to receive envelopes released by the envelope feeder, the envelope feeder does not have to slow down substantially in order to wait for the released envelope to clear the feeding path.

Description:
This application is a continuation of U.S. Ser. No. 09/471,755 filed on Dec. 23, 1999, entitled “Dual Bin Envelope Supply Device and Method,” now issued as Pat. No. 6,290,226. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to an envelope insertion machine and, more feeder and an envelope staging area in the envelope insertion machine, and, more particularly, to the envelope supply paths for connecting the envelope transport paths between an envelope. 
     BACKGROUND OF THE INVENTION 
     In an envelope insertion machine for mass mailing, there is an envelope feeder on one end of the machine to sequentially release envelopes directly into an envelope staging area, and a gathering section on the other end where the enclosure material is released and gathered. If the enclosure material contains many documents, these documents must be separately released from different enclosure feeders. The released documents must also be collated into a stack and moved to the envelope staging area where the document stack is inserted into an envelope by an insertion engine. In some envelope insertion machines, however, the movement of the envelopes from the envelope feeder to the envelope staging area involves a right-angle turn. In those machines, although the envelopes can be fed at a high feeding rate and moved at a high speed after they are released, each envelope must be slowed down or momentarily stopped before it can make a drastic turn to enter into the envelope staging area. 
     Because of the requirement for the right-angle turn, the envelope feeder must also be slowed down to wait for the previously released envelope to move out of the feeding path. Thus, the right-angle turn movement reduces the feeder rate that is otherwise attainable by the envelope feeder. Consequently, the throughput of the envelope insertion machine is also substantially reduced. In a high-speed envelope insertion machine wherein the machine throughput is required to reach 18,000 insertions per hour, the reduced velocity of the envelopes due to the right-angle turn requirement causes a bottle-neck in the entire insertion system. 
     Therefore, it is advantageous and desirable to provide a method and a system for transporting the envelopes released from the envelope feeder to the envelope staging area so as to solve the above-described bottle-neck problem in an envelope insertion machine. 
     SUMMARY OF THE INVENTION 
     The present invention provides an envelope transport system having two envelope bins and two envelope supply paths linking the envelope bins to an envelope feeder. Each envelope bin is used to temporarily store an envelope before that envelope is moved to the staging area. The envelope supply paths are controlled by a flipper gate which alternately opens one path and closes the other so as to allow an envelope feeder to feed an envelope into one envelope bin while waiting for the preceding envelope to be transported out of the other envelope bin to the staging area. With the dual envelope bins connected to the dual supply paths, the envelope feeder does not have to slow down substantially in order to wait for the released envelopes to clear the feeding path. 
     Accordingly, the first aspect of the present invention is to provide a system for transporting envelopes in an envelope insertion machine having an envelope feeder and an envelope staging area. The system comprises two envelope bins, each of which is connected to a different envelope supply path to receive one envelope at a time from the envelope feeder in an alternate fashion so as to allow the received envelope to slow down before it is transported out of the envelope bin to the envelope staging area. 
     Preferably, each envelope bin has a catch mechanism located at the bin entrance to prevent an envelope, which has entered the bin, from moving out of the entrance in an opposite direction, and a stop mechanism located at the opposing end to keep the entered envelope from moving out of the envelope bin from the opposite end and to momentarily slow down the entered envelope. 
     Preferably, each envelope bin has a width defined by the stop mechanism and the catch mechanism and the bin width is adjustable in accordance with the width of the envelope. 
     Preferably, a coupling device mechanically connects the two envelope bins so that the width of both envelope bins can be simultaneously adjusted. 
     Preferably, the stop mechanism is operable in a first position to stop an entering envelope from moving out of the bin end along the entering direction and a second position to allow the entered envelope to move out of the bin along the entering direction, if needed. 
     The second aspect of the invention is to provide a method of transporting envelopes released by the envelope feeder to the envelope staging area in the envelope insertion machine. The method comprises the step of feeding the released envelopes into two envelope bins in an alternate fashion so that one envelope is temporarily stored in one of the envelope bins while the preceding envelope is transported out of the other envelope bin to the staging area. 
     The third aspect of the invention is to provide a method of simultaneously adjusting the width of the dual envelope bins. The method comprises the steps of: a) engaging the stop mechanism and the catch mechanism of one envelope bin with a first adjustment device for adjusting the distance between the mechanism and the catch mechanism of that envelope bin; b) engaging the stop mechanism and the catch mechanism of the other envelope bin with a second adjustment device for adjusting the distance of the stop mechanism and the catch mechanism of that other envelope bin, and c) coupling the first adjustment device to the second adjustment device so that the distance between the stop mechanism and the stop mechanism of each of the envelope bins can be simultaneously adjusted. 
     The present invention will become apparent upon reading the description taken in conjunction with FIGS. 1 to  8 . 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an envelope insertion device showing an envelope feeder and an envelope staging area. 
     FIG. 2 is a schematic representation of an envelope insertion device showing the relationship between the envelope feeder and the dual bin envelope supply device of the present invention. 
     FIG. 3 is a schematic representation of the dual envelope bins showing the catch mechanism and the stop mechanism for each envelope bin. 
     FIGS. 4A and 4B are isometric views of the catch mechanism showing the detailed structure thereof. 
     FIGS. 5A and 5B are isometric views of the stop mechanism showing the two operable positions of the stop mechanism. 
     FIGS. 6A and 6B are isometric views of the adjustment mechanism for adjusting the separation between the stop mechanism and the catch mechanism for each envelope bin. 
     FIG. 7 is a cross-sectional view of part of the adjustment mechanism showing the mechanical linkage between an adjustment shaft and an extension shaft. 
     FIG. 8 is a side view of a coupling device showing the mechanical linkage between the two envelope bins for simultaneously adjusting the width of the envelope bins. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a perspective view of a section of an envelope insertion machine  100 , showing an envelope staging area  10  where enclosure material (not shown) gathered at the upstream end of the envelope insertion machine  10  is inserted into an envelope (not shown). Also shown in FIG. 1 is a section of an envelope feeder  20  and the dual bin envelope supply device  40  of the present invention. When in use, the dual bin envelope supply device  40  must be pushed along a direction  102  to be placed directly under the envelope staging area  10  so that envelopes entering the dual bin supply device  40  are sequentially moved to the envelope staging area  10  for enclosure material insertion. 
     FIG. 2 illustrates the relationship between the envelope feeder  20  and the dual bin envelope supply device  40 . As shown, the dual bin envelope supply device  40  has a first envelope bin  42  and a second envelope bin  44  to receive envelopes  22  fed by the envelope feeder  20  through dual envelope supply paths  30 . The dual envelope supply paths  30  include a first entrance  31  and a second entrance  32 . A flipper gate  34  is used to alternately open and close the entrances  31  and  32  so that the envelopes  22  are fed by the envelope feeder  20  in an alternate fashion into the first entrance  31  and the second entrance  32 . The envelopes  22  entering through the first entrance  31  and second entrance  32  are transported through a first exit  36  and a second exit  37 , respectively, into the envelope bins  42 ,  44  with the aid of transport belts  46  and  48  along a direction  47 . As shown, each envelope bin  42 ,  44  has a catch mechanism  50  at one end to admit an envelope  22  into the envelope bin and a stop mechanism  60  at the other end to retain an entered envelope (not shown) within the envelope bin  42 ,  44 . 
     As shown in FIG. 3, each of the envelope bins  42 ,  44  has a width W. Preferably, both envelope bins  42 ,  44  have the same bin width W. The bin width W of the envelope bin  42 ,  44  is defined by the catch mechanism  50  at the bin entrance  51  and the stop mechanism  60  at an opposite end  61 . The catch mechanism  50  is mounted on a front end housing  52  while the stop mechanism  60  is mounted on a rear end housing  62 . An adjustment mechanism  70 , which is mechanically connected to the front end housing  52  and the rear end housing  62 , is used to adjust the separation between the catch mechanism  50  and the stop mechanism  60 , and therefore the width W of the envelope bins  42 ,  44 , in accordance with the width of the envelope  22 . As shown, the envelope  22  enters the envelope bin  44  along an entering direction  24  through the bin entrance  51 . The catch mechanism  51 , which is a one-way device, is used to prevent an envelope  22  which has entered the bin  42 ,  44  from moving out of the bin  42 ,  44  through the entrance  51  along a direction opposite the direction  24 . The stop mechanism  60  is used to keep the entered envelope  22  from moving out of the bin  42 ,  44  through the opposite end  61  along the entering direction  24 . Also shown in FIG. 3 are a first adjustment shaft  90 , and a first extension shaft  92  which are engaged with the adjustment mechanism  70  of the first envelope bin  42 . An adjustment knob  98  is used to turn the first adjustment shaft  92  in order to adjust the width W of the first envelope bin  42  via the adjustment mechanism  70 . Furthermore, a second adjustment shaft  94  and a second extension shaft  96  are engaged with the adjustment mechanism  70  of the second envelope bin  44  for adjusting the width W of the second envelope bin  44 . A coupling device  200  is used to provide a mechanical coupling between the first extension shaft  92  and the second adjustment shaft  94  so that the width W of both the first envelope bin  42  and the width W of the second envelope bin  44  can be simultaneously adjusted. 
     FIGS. 4A and 4B are isometric views of the catch mechanism. As shown in FIG. 4A, the front end housing  52  includes a roller  54  and a spring  56  positioned at the bin entrance  51  to push an incoming envelope  22  against the transport belt  46 ,  48  in order to move the envelope  22  into the envelope bin  42 ,  44 . The catch mechanism  50 , which has a gap G (FIG. 4B) wider than the width (not shown) of the transport belt  46 ,  48 , is placed into the moving path of the envelope  22 . As the envelope  22  is moved into the envelope bin  42 ,  44  along the entering direction  24 , it depresses the stop mechanism  51  away from the transport belt  42 ,  44 . After the envelope  22  has entered into the envelope bin  42 ,  44 , the catch mechanism  51  returns to its original position thereby preventing an entered envelope from moving out of the envelope bin  42 ,  44  through the front entrance  51 . 
     As shown in FIGS. 5A and 5B, the stop mechanism  60  is pivotably mounted on the rear end housing  62  at pivot  64  so that the stop mechanism  60  can be operated in a first position and a second position. In normal operation, as shown in FIG. 5A, the stop mechanism is operated at the first position. As shown in FIG. 5A, the stop mechanism  60  is placed into the moving path of an envelope  22  which enters the envelope bin  42 ,  44  along the direction  24 . When operated in the first position, the stop mechanism  60  keeps the entered envelope  22  from exiting the envelope bin  42 ,  44  through the rear end  61  along a direction  26 . Accordingly, the entered envelope  22  is temporarily stored in the bin  42 ,  44  until it is moved out of the bin  42 ,  44  in a direction perpendicular to the direction  24 . 
     In practice, when an envelope  22  enters an envelope bin  42 ,  44 , the flap (not shown) of the envelope  22  is opened slightly by an opening device (not shown). After the envelope  22  is moved out of the bin  42 ,  44  to the envelope staging area  10 , the flap is fully flipped out to allow enclosure material to be inserted into the envelope  22 . Thus, if the flap of the entered envelope  22  is not opened slightly by the opening device after the envelope  22  has entered the envelope bin  42 ,  44 , the flap will not be fully flipped out in the envelope staging area  10 . Therefore, that envelope must be ejected from the envelope bin  42 ,  44  through the opposite end  61 . In that situation, the stop mechanism  60  is operated at the second position as shown in FIG.  5 B. 
     As shown in FIG. 5B, the stop mechanism  60  is moved away from the transport belt  46 ,  48 . At the same time, a roller  66  pushes an entered envelope (not shown) against the transport belt  46 ,  48  causing the entered envelope to be moved out of the envelope bin  42 ,  44  through the opposite end  61  along a direction  26 . 
     FIG.  6 A and FIG. 6B are isometric views of the adjustment mechanism  70  for adjusting the bin width W of the first envelope bin  42 . As shown, the adjustment  70  includes a pinion  72  engaged with a first rack  74  and a second rack  76  for movement. The first rack  74  is fixedly mounted on a first mounting bracket  78  and the second rack  76  is fixedly mounted on a second mounting bracket  80 . When the pinion  72  turns in a counter-clockwise direction  152 , the first mounting bracket  78  is caused to move along a direction  154  while the second mounting bracket  80  is caused to move along an opposition direction  156 . The first mounting bracket  78  is used to mount the front end housing  52  (FIG.  3 ), and the second mounting bracket  80  is used to mount the rear end housing  62  (FIG.  3 ). Thus, when the pinion  72  turns in the counter-clockwise direction  152 , the front end housing  52  and the rear end housing  62  are caused to move in opposite directions away from each other, thereby increasing the width W of the first envelope bin  42 . Similarly, when the pinion  72  turns in a clockwise direction, the front end housing  52  and the rear end housing  62  are caused to move in opposite directions towards each other, thereby reducing the width W of the first envelope bin  42 . 
     The pinion  72  is fixedly mounted to a worm wheel  84 , which is in direct contact with a worm gear  82  for motion. The worm gear  82  is coupled to the first adjustment shaft  90  which is fixedly connected to the adjustment knob  98 . When the adjustment knob  98  is turned in a clockwise direction  150 , the worm gear  82  is caused to turn the worm wheel  84  and the pinion  72  in the counter-clockwise direction  152 . Similarly, when the adjustment knob is turned in a counter-clockwise direction (not shown), the pinion  72  is caused to turn in a clockwise direction. As shown in FIGS. 6A and 6B, the extension shaft  92  is coupled to the first adjustment shaft  90  through the worm gear  82  so that the first extension shaft  92  is caused to turn in synchronism with the first adjustment shaft  90 . The detail of the coupling between the first adjustment shaft  90  and the first extension shaft  92  is shown in FIG.  7 . Preferably, the coupling between the second adjustment shaft  94  and the second extension shaft  96  is similar. 
     As shown in FIG. 7, the worm gear  82  has an aperture  83  along a rotation axis  135  to allow the first extension shaft  92  to be coupled to the first adjustment shaft  90 . In particular, the aperture  83  is a through hole having a D-shaped cross section (not shown), and the extension shaft  92  has an end tip  93  having a D-shaped cross section to fit the aperture  83 . The end tip  93  of the extension shaft  92  is secured to the first adjustment shaft  90  by one or more set screws  97 . Due to the fitting of the D-shape end tip  93  to the D-shaped aperture  83 , the worm gear  82  is caused to turn in synchronism with the first extension shaft  92 , which is turned along with the first adjustment shaft  90 . 
     FIG. 8 illustrates the coupling device  200  which provides a mechanical coupling between the first extension shaft  92  of the first envelope bin  42  and the second adjustment shaft  94  of the second envelope bin  44 . As shown, a first pulley  210  is fixedly mounted to the extension shaft  92  for rotation, and a second pulley  220  is fixedly mounted to the second shaft  94 . A belt  230 , preferably a timing belt, is used to provide linkage between the first pulley  210  and the second pulley  220  so that the second pulley  220  is caused to rotate in synchronism with the first pulley  210 . Furthermore, two idler pulleys  240  and  242  are used to push the belt  230  away from the pulleys  92  and  94  to make a passage way  250  so as to allow an envelope ejected out of the envelope bins  42  and  44  along the direction  26  (FIG. 5B) to move out of the dual bin envelope supply device  40 . 
     Thus, what has been described is a system for transporting envelopes from an envelope feeder to an envelope staging area. The system includes two envelope bins to receive envelopes fed by the envelope feeder from two envelope supply paths, wherein the supply paths are alternately opened and closed by a flipper gate. In effect, the envelope transport system of the present invention provides a parallel process to increase the throughput of the envelope insertion machine. It should be noted that parallel processing of envelopes can also be carried out in an envelope supply device having three or more envelope bins and supply paths. Furthermore, the above-described method for the adjustment of the bin width involves rack-and-pinion systems. However, it is also possible to use spur gears or other mechanical means to adjust the separation between the front housing and the rear housing. 
     Therefore, 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.