Abstract:
A mail inserter machine having a drive system including a drive motor, gear reducer unit and indexing unit. The drive motor and gear reducer communicate by a belt driven around pulleys residing in a plane and the gear reducer communicating through a direct shaft drive with the indexing unit. The indexing unit rotating a belt pulley which carries a belt connected to a timing pulley for driving a cross shaft. The belt pulley and timing pulley residing in a plane parallel to said drive motor and gear reducer unit pulleys. Said drive system arranged in a lower portion of the mail inserter machine chassis, whereby the said parallel planar pulleys thereby generate forces vectored in parallel directions enabling a greater size, greater precision, high durability, and greater dynamic stability for the mail inserter machine.

Description:
RELATED APPLICATION 
     This application is a continuation of Ser. No. 08/760,387, filed Dec. 4, 1996, now abandoned, which is a continuation-in-part of patent application Ser. No. 08/446,403 filed May 22, 1995 now abandoned, which is incorporated herein. 
    
    
     TECHNICAL FIELD 
     This invention relates to a mail inserter machine, more particularly to an improved mail inserter machine that inserts documents into mailing envelopes and seals the envelopes, and that operates more efficiently and requires significantly less time to repair and replace parts. 
     BACKGROUND OF THE INVENTION 
     Presently, there exist a number of machines that perform the function of inserting envelopes, manipulating garbage bags for packaging, and generally for transferring items on a machine from one location on the machine to other locations on the machine. 
     Many of the envelope inserting machines have the capacity for performing the functions of separating inserts from a stack, opening the envelopes, inserting mailing inserts inside the envelopes, putting pre-determined printed matter on the envelopes, and sealing the envelopes. Having a machine that can perform all these functions can be very beneficial to the user, especially for the user having a large capacity of mailings to be mailed. 
     However, one major disadvantage of using this type of machine is the time and expense used to repair and service the machines. Specific functioning components on the mail inserter machine which require substantial time and cost to repair and service include the front table cam shaft, the upper drive shaft, and the main drive system. 
     The front table cam shaft is a continuous rotating shaft fitted with individually adjustable cams. Each cam on the shaft controls a separate function in the machine. For example, the cams may operate a stacker for stacking envelopes, a flap closer for closing the flaps of envelopes, a sucker bar for moving suction cups which adhere to the envelopes, and jaw openers used to grip the envelopes. Of course additional cams can exist on the front table cam shaft for performing additional functions. During the manufacturing of a front table, the installation of the cam shaft requires that bearing assemblies be bolted onto the table, and then a line reamer is run through the bearing blocks. Each bearing block has an individual bushing pressed therein. The reamer opens the bushings inside diameter to the equivalent size of the outside diameter of the cam shaft. The bushings are approximately in line with each other prior to reaming. Line reaming will match and line up the bushings inside diameter exactly. Once the bearing blocks are line reamed they can not be replaced individually without extensive time and effort. One bushing may be reamed slightly higher or lower than another bushing, while another may be further forward on the table than other bushings. If one bearing block bushing wears out because of extensive machine use or lack of lubrication before others, the individual block bearing bushing may not have to be replaced but can be line reamed. Line reamers are usually not available in the field therefore a hand reamer would be used. Shimming the bearing block would be required. Occasionally, bushing is reamed oversized deliberately to cut down on a lengthy repair process. This is not good practice and will result in repeat bushing failure. Once the bearing blocks are line reamed assembly of the front table can begin. Installation of the cam shaft along with mounting and all the cams, collars, sprockets, and gears onto the shaft is first, everything else is attached on top or along side of the cam shaft. Replacing a cam shaft can be strenuous and time consuming. To replace a cam shaft, the shaft has to be rotated to loosen all the set screws attached within the cams and components mounted on the shaft. The cams and components are moved sideways along the shaft to allow set screw burr marks to be removed by filing to enable components to be removed from the shaft. Sometimes the cam shaft is bent to the extent that the shaft can not be rotated. The shaft is driven by a sprocket keyed to the shaft. Keys are usually drilled, pinned and fitted to the cam shaft for rotating the cam shaft. If the cam shaft bends it usually bends where the sliding sprocket is, and the key is usually bent as well. Sometimes a damaged cam shaft has to be cut in half to be removed. Clearance for using a hack saw or the like to cut the shaft and gain access to the non-turning cam shaft and set screws requires extensive time to remove the front table top plate and many other attached parts. Removal of the bearing block mounting bolts, sprocket guide and drive chains must also be completed before removing the cam shaft. This removal process takes a number of hours. Users of the mail inserter machine usually cannot afford lengthy repairs and down-time necessary for repairing or replacing an individual bushing mounted on the front table around the shaft. 
     Another problem area on inserter machine requiring substantial time and cost to service and repair is a rotatable upper drive shaft. This shaft has a round diameter and has mounted therearound a number or bearings and bearing blocks supporting and aligning the shaft. The shaft also has a keyway slot therein for a sliding bevel gear assembly. Present manufacturing of the sliding bevel gear include a key which is fastened to the inside key way of the bevel gear. In operation, as the shaft rotates, the shaft aligns itself within the supporting bearing blocks. In aligning within the bearing blocks, the shaft places concentrated loads on the bearing blocks supporting it. This aligning causes the concentrated loadings on the bearing blocks to eventually wear on the supporting bearings inside the bearing blocks, thereby creating a need to replace the worn bearings. To replace the worn bearings, the bearing block or blocks containing the worn bearings must be removed from the table it is mounted upon. Since the shaft is one continuous elongated member, when removing one bearing block to replace the bearing inside, the bearing block must be detached from the supporting table and slid off the end of the shaft to allow the bearing block. On the lower cam shaft, several blocks may have to be removed to get to the worn block. Conversely, when replacing the new or repaired bearing blocks back onto the table and shaft, the other bearing blocks must also be positioned back on the shaft and mounted back onto the supporting table. When remounting the bearing blocks, extensive time must be taken to align the bearing blocks with the shaft for effective and efficient rotation of the cam shaft. 
     A third component of the mail inserter machine requiring substantial time and cost to service and repair is the main belt drive system which drives the mechanisms of the machine. In present envelope inserter machines, the main drive systems transfer the driving force from a drive motor to a prior art speed reducer via a drive belt. Output drive from the prior art speed reducer is used to transfer rotational force to both a cam indexing box and to a cam shaft via drive chains. During operation, the prior art drive chains stretch, sprockets wear, and eventually require replacement. As the chains stretch, tension and timing functions may require occasional readjustment to compensate for the stretching (or chain/sprocket wear). The prior art cam indexing box drives the indexing portion of the inserter via a ring and pinion gear 3-to-1 drive configuration. The ring and pinion gear are aligned, and corresponding bearing posts are pinned to avoid change in alignment. This alignment process is service intensive and time consuming 
     SUMMARY OF THE INVENTION 
     The present invention contemplates to eliminate the aforementioned disadvantages of the front table cam shaft, the upper drive shaft, and the main drive system. 
     To avoid lengthy repairs and down time caused by having to replace worn bearings on a front table cam shaft, an improved front table cam shaft is provided. The improved front table camshaft is a continuously rotating shaft, with individually adjustable cams mounted on it. The cams control operating functions of the front table, such as opening envelope flaps, opening envelopes for insertion, detecting the envelopes and envelope flap closing. Other cams may also be used to operate additional functions. The shaft has either three (3) or two (2) separate sections depending on its length. Starting from one end of the shaft (the three (3) section shaft), a first shaft section having a round cross-section extends through two (2) ball bearing split cap bearing blocks into a flexible zero backlash coupling. An improved ball bearing split cap bearing block design allows each of the shaft sections to be removed without having to slide a shaft section completely through any individual bearing block. The top portion the bearing block can be unclamped, allowing a shaft section to be simply lifted upward and removed from the assembly. Coupled to a second shaft section having a round cross-section, the shaft extends through two more ball bearings secured in split cap bearing blocks. A two (2) section shaft uses a solid first and second section. The third section of the camshaft has round ends with a hexagonal main body. The round ends extend through the is ball bearings. The hexagonal portion of the shaft is provided for a mounted sliding sprocket which has a corresponding machined hexagonal or square bore. The purpose of the machined hexagonal or square shape is to allow for lateral travel of the front table, while maintaining sprocket alignment with the drive sprocket in the main machine frame without the use of a key. The sliding sprocket has a groove therein into which a guide is positioned. The guide is also attached to the machine frame. As the front table moves laterally, the sprocket, which is held in drive alignment by the guide, does not travel laterally. The hex shaft which moves through the sprocket does travel laterally with the table. The sprocket is not fastened to the hex shaft. The shaft is free to slide through the sprocket. The improved front table cam shaft includes bearing blocks fitted with roller bearings. The sectional section shaft design allows for easy removal of a section needing repair by just sliding the coupling back and removing the section. The front table top plate does not have to be removed to access the cam shaft. If the cam shaft is bent at the sliding sprocket, that particular section can be removed without having to remove the entire sectional shaft. The sliding sprocket portion of the roller bearing style front table is a heavy machined hexagonal or square shaft with no key required to be rotated by the sprocket on the shaft. The machined shaft portion acts as a key and is turned down at both ends to fit into the roller bearings coupling and bevel gear. The roller bearing block has matching mounting hole locations and cam shaft centers as the standard bearing blocks with bushings. The advantage of using the same mounting hole location and cam shaft center is that cam shaft replacement service time is reduced by using the roller bearing design with sectional shafts. The cam shaft outside diameter remains the same as the standard one piece shaft; however, the outside diameter is not a critical issue. Time to bolt down the bushing blocks, ream, fit and install various cam and related parts is greatly reduced through use of a sectional shaft, since an entire one-piece shaft with all its accompanying attachments\cams do not have to be removed. The improved sectional shaft allows for removal of only one section of the sectional shaft to replace or repair any bearing block, cam, or other component mounted on that particular section of the shaft. Additional benefits of the use of roller bearing in the improved front table cam shaft include less of a need to lubricate the bearing, unlike the standard bushing design, thereby requiring less torque to operate the machine. Reduced load translates into reduced power (electrical) and reduced cost to operate the mail inserter machine. 
     An improved upper drive shaft is also provided. The improved upper drive shaft uses roller bearings for a smoother drive and easier assembly. The shaft exists as an anti-fatigue machined hexagonal or square steel shaft. A bevel gear is attached to a machined hexagonal or square bore tube. A major advantage of the improved upper drive shaft is its machined cross-section. The gear assembly is driven by sliding the machined tube over the machined upper drive shaft thereby providing for full contact between the machined tube and the matching machined upper drive shaft. The present round shafts have gear assemblies driven by a key in a keyway which provide for less than 10% shaft drive contact. The improved drive shaft provides for fitted full contact drive shaft. 
     Also provided in the improved mail inserter is an improved main drive system. The improved main drive system has simplified the present method that transfers force from a drive motor to a speed reducer via a drive belt by transferring the drive force from the drive motor to a one unit reducer cam (indexing) box via a belt. The cam shaft output drive, the indexing drive is taken directly to the drive shafts without the use of an additional 3-to-1 ring and pinion gear drive via timing belts. The direct drive approach, via timing belts, eliminates lining up and fitting the ring and pinion gear. The ring and pinion gears require a perfect mesh to avoid destroying the gear set. Alignment can be service intensive and time consuming. This direct drive approach reduces the number of parts required to operate the main drive system. Reduction of parts translates into less parts to service, maintain and replace. The improved main drive system also provides a smoother drive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front plan view on the mail insetter machine the front table cam shaft, the upper drive shaft, and the main drive system. 
     FIG. 2 is a perspective view of the front table cam shaft with attached components. 
     FIG. 3 is a perspective view of a ball bearing split cap bearing block. 
     FIG. 4 is a front plan view a sprocket having a hexagonal bore. 
     FIG. 5 is a top plan view of the front table cam shaft and upper drive shaft. 
     FIG. 6 is a side plan view of the front table cam shaft and upper drive shaft. 
     FIG. 7 is a plan side view of a first cam shaft section. 
     FIG. 8 is a plan side view of a second cam shaft section. 
     FIG. 9 is a plan side view of a third cam shaft section. 
     FIG. 10 is a perspective view of all three sections of the front table cam shaft. 
     FIG. 11 in a plan front view of a machined hex tube with a bevel gear attached thereto. 
     FIG. 12 is a side view of the machined hex tube with a bevel gear attached thereto. 
     FIG. 13 is a front plan view of the first embodiment of the main drive system. 
     FIG. 14 is a top plan view of the first embodiment of the main drive system. 
     FIG. 15 is a rear view of the second embodiment of the main drive system of the mail inserter machine of FIG.  1 . 
     FIG. 16 is perspective view of a section of the improved front table cam shaft showing a section of the shaft, a sprocket, a sprocket guide and a guide bracket. 
     FIG. 17 is a perspective view of the mail inserter machine of FIG. 1 looking at the rear thereof as in FIG. 15 illustrating the second embodiment of the main drive system. 
     FIG. 18 is a perspective view of the mail inserter machine of FIG. 1, from a front view thereof and showing the second embodiment of the main drive system as in FIG.  15 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The principles of the invention are particularly useful when embodied in a mail inserter machine as shown in FIG. 1, generally indicated by the numeral  10 . In a preferred embodiment as better seen in FIG. 1, the improved mail inserter machine includes a front table cam shaft  12 , an upper drive shaft  30 , and a main drive system  50 . 
     The front table cam shaft  12  consists primarily of a cam shaft  14  having three (3) shaft sections  14   a ,  14   b , and  14   c  as seen in FIGS. 2,  7 - 10 . First cam shaft section  14   a  has a uniform round cross-section throughout its length. Second cam shaft section  14   b  also has a uniform round cross-section throughout its length. Third cam shaft section  14   c  consists of a round extending section  14   c , an integral hexagonal section  14   d  and a round end section  14   e . As seen in FIG. 2,  5 , and  6  the first cam shaft section  14   a  extends through two (2) ball bearing split cap bearing blocks  16  into a flexible zero backlash coupling  18 . As seen in FIG. 3, the one piece split cap bearing block  16  is comprised of a bearing block top clamping portion  16   a , and bearing block bottom portion  16   b , and ball bearings  16   c  positioned between the top and bottom bearing block portions  16   a ,  16   b . Fasteners  16   d  extend through top portions  16   a  and  16   b  into a front table plate  24  to attach the bearing block  16   a  and bearing and the cam shaft  14  to the front table plate  24 . The fastener  16   d  on the solid side of the block locates to block position. The fastener on the split side clamps the bearing into position. The first cam shaft section  14   a  extends to the second cam shaft section  14   b  where it is coupled to the second cam shaft section  14   b  with a coupling  18 . The second cam shaft section  14   b  extends through another two (2) ball bearing sets  16   c  secured in split cap bearing blocks  16 . The second cam shaft section further extends to a third cam shaft section  14   c . The second cam shaft section  14   b  is coupled to the third cam shaft section  14   c  with a coupling  18 . The third cam section  14   c  extends into an integral machined section  14   d  and then into an integral round end section  14   e . The integral round end section  14   e  extends into a set of ball bearings  16   c  maintained in a ball bearing split cap bearing block  16 . As seen is FIGS. 2,  4  and  16 , a sprocket bore  22   a  having a sprocket  22  mounted thereon is mounted on the integral camshaft machined hexagonal section  14   d  (FIG.  9 ). The sliding sprocket  22  has a groove  22   a  therein (FIG.  16 ). A guide  26  is positioned within the groove  22   a  of the sprocket  22 . The guide  26  is also mounted to the main frame of the mail inserter  10  via guide bracket  27 . The third cam shaft  14   c  is free to move through the sprocket  22  which is fixed to the main frame of the inserter via a guide bracket  27  by guide  26  (FIG.  16 ). As the front table  12  moves laterally, the sprocket  22 , which is held in drive alignment by the guide  26 , does not travel laterally. More specifically, the front table  12  and all parts mounted to the table  12  move laterally. The sprocket  22 , which is not mounted to the table  12 , but is mounted directed to the fixed main frame via guide bracket  27  does not move. As better seen in FIG. 16, an L-shaped guide bracket  27  is attached to the machine frame. Guide  26  is attached to guide bracket  27  by screws  29   a  and nuts  29   b . A cam shaft bevel gear  28  is attached to the end of the cam shaft round end section  14   e  (FIGS. 2,  9  and  10 ). 
     Mounted above the front table cam shaft  12  is an upper drive shaft  30  (FIG. 1,  5  and  6 ). The upper drive shaft  30  has a uniform machined hexagonal cross-section. A sliding bevel gear  32  having a machined hex tube  38  with a hexagonal bore therein is mounted on the upper drive shaft  30  (FIG. 5,  6 ,  11  and  12 ). The upper drive shaft  30  extends through two (2) bearing blocks  42  having hexagonal bores bearings mounted therearound. As bevel gear  34  turns, it transmits rotational forces to corresponding sliding bevel gear  32 , thereby, turning the hex tube  38  which in mounted inside the bore of the sliding bevel gear  32 . The inner bore surface of the machined hex tube  38  is in close tolerance contact with the machined hexagonal shaft  30 . Turning of the hex tube  38  mounted on the hexagonal shaft  30 , thereby, causes the hexagonal shaft  30  to rotate with a corresponding rotational motion. 
     The improved mail inserter machine also has provided an improved main belt drive system  50  to the machine&#39;s  10  various functions. In a first embodiment as seen in FIGS. 1,  13  and  14 , the drive system  50  consists primarily of an electrically powered drive motor  52  mounted on a lower mounting plate  60  having a motor pulley  52   a , a drive unit  54  having a receiving drive pulley  54   a , an indexing clutched timing belt pulley  54   b , and a continuous drive pulley  54   c . The main drive system  50  also includes a cam shaft drive  56   b . A drive motor “V” belt  55  is in rotational connection with the indexing clutched timing belt pulley  54   b  and the indexed timing pulley  56   a . As will be appreciated by one of ordinary skill upon review of FIG. 13, pulley  54   a  and pulley  54   c  rotate in planes perpendicular to one another. 
     The drive motor  52  is mounted to a lower frame base  72  accessible from the lower rear side in the mail inserter machine  10 . In the preferred embodiment the drive motor is DC powered. The drive unit  54  is mounted to a mounting plate  60 . The mounting plate  60  is mounted to an elevated shelf  64  accessible from the rear of the mail inserter machine  10 . The mounting plate  60  has a plurality of slots  60   a  therein for bolting fasteners  62  therethrough to securely mount plate  60  to shelf  64 . A drive shaft  66  extends axially from drive unit  54  to bushing block  68  which is rotatably mounted to shelf  64 . The cam indexing box  56  is mounted to an upper machine side rail  70  which extends horizontally across inside the rear of the mail inserter machine  10 . In operation, the drive motor  52  powers the machine  10  by transferring power to the drive unit  54  via drive belt  58 . 
     As seen in FIG. 15, in second embodiment which utilizes a heavier and more powerful drive unit, the drive system  150  consists primarily of an electrically powered drive motor  152  having a motor pulley  152   a  and is mounted on a lower frame base  172 , a drive gear reducer unit  159  having a receiving drive pulley  159   a , and an indexing unit  154  having an indexing output clutched timing belt pulley  154   b . The main drive system  150  also includes a cam shaft drive pulley  167 . A timing chain  155  is in rotational connection with the belt pulley  154   b . The gear reducer unit  159  is mounted to the lower frame base  172  adjacent the drive motor  152 . A drive shaft  166  extends axially from the gear reducer unit  159 . A cam shaft drive pulley  167  is mounted on the end portion of the drive shaft  166 . A continuous drive cam shaft  169  is rotatably mounted on an elevated shelf  164  via bushing blocks  168 . A cam shaft pulley  171  is mounted on the cam shaft  169  directly above the cam shaft drive pulley  167 . A timing belt  158   a  is mounted on and between cam shaft pulley  171  and drive shaft pulley  167 . The gear reducer unit  159  has two output drive shafts  166  and  157 , wherein shaft  157  is directly connected by a coupling  173  to an input shaft  174  of the cam indexing unit  154 . The cam indexing unit  154  via a timing chaim  155  drives the cross shaft timing pulley  156   a  which is positioned on the upper rear machine side rail  170 . The shaft  156   c  extends horizontally across the inside of the machine, rear to front. In operation, the drive motor  152  powers the machine  10  by transferring power to the the drive pulley  159   a  via V drive belt  158 , and thereby driving the output shaft  166  and  157 . 
     As will be appreciated by one of ordinary skill upon review of FIG. 15, pulley  159   a  and pulley  154   b  rotate in planes parallel to one another, and pulley  156   a  rotates in a plane which is coplanar with pulley  154   b.    
     Further, as is apparent in FIGS. 1,  2 ,  5 - 6 ,  13 - 15 , and as is known by one of ordinary skill, envelope inserter machines  10  have a principal axis along which rail  70 , base  72 , front table plate  24 , shafts  14 , 30 , lower mounting plate  60  and shelf  64  are aligned. The drawings show that pulleys  52   a ,  54   a ,  54   b  and  56   a  (in the first embodiment) and pulleys  152   a ,  159   a ,  154   b  and  156   a  (in the preferred embodiment of FIGS. 15,  17  and  18 ) all rotate in planes parallel to the principal axis. Various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention, however, it must be understood that these particular arrangements merely illustrate and that the invention is to be given its fullest interpretation within the terms of the appended claims.