Abstract:
A connection device is provided for meshing of gears on disparate modules, such as those that form a mailing machine. A tongue having a rack can extend from a first module into a cavity formed in the second module. A spur gear is mounted to the second module and can engage the rack of the tongue received into the cavity. A mechanism controls movement of the first spur gear. The mechanism can include a drive gear meshed with the first spur gear and concentrically mounted on one end of a drive shaft with a worm gear mounted concentrically on an opposing end of the drive shaft. Rotation of the worm gear causes the spur gear and the drive gear to rotate and cause movement in the rack received into the cavity and separate or bring together the modules as a result of the movement in the rack.

Description:
BACKGROUND 
     This invention relates generally to the field of machine assembly, and more particularly to assembling and securing two modules of a mailing machine. 
     Generally, a mailing machine transports envelopes and other mailpieces along a deck so that various functions may be performed on the mailpiece at different locations along the deck. For example, one location along a deck may weigh the mailpiece, another location may seal the mailpiece and still another location may apply indicia for postage to the mailpiece. Apparatus for performing the various functions at each location can be built into disparate modules that can be assembled to create a mailing machine with desired functions. A drive mechanism can include drive rollers and/or belts mounted along the deck. A radial portion of the drive rollers or belt can contact an envelope to propel the envelope along the deck. The drive rollers can extend, for example, through aligned cutouts in the deck. The drive mechanism moves the envelope along the deck to different locations on the deck where a function may be performed. 
     When assembled, the modules can form the transport deck and also include apparatus to perform various functions on a mail piece as the mail piece traverses the transport deck. For example, one module may be primarily concerned with receiving and feeding envelopes into additional modules making up the mailing machine. Another module may have a primary purpose of performing a sealing function by moistening an adhesive which is present on the inner surface of an envelope flap before the envelope is fed into a nip which serves to seal the envelope with the moistened adhesive. Still another module may weigh the envelope or print indicia on the envelope. 
     Assembly of two or more modules can be accomplished at a customer site and can involve joining of irregular shapes which are included in a transport deck as well as joining of drive mechanisms utilized to transport the envelope along the transport deck. Since integration of two modules may be accomplished by a customer, it is beneficial if the assembly can be done without tools while providing secure and reliable latching and unlatching which can include mechanical and electrical interfaces. 
     Therefore, it would be advantageous to provide apparatus and methods that overcame the drawbacks of the prior art. In particular, it would be desirable to provide apparatus and methods that facilitates the assembly of modules on a mailing machine. 
     SUMMARY 
     Accordingly, a connection device is provided that facilitates assembly of the modules to form a mailing machine. A tongue having a rack can extend from a first module into a cavity formed in a second module. A spur gear is mounted to the second module and can engage the rack on the tongue received into the cavity. A mechanism can control movement of the first spur gear. The mechanism can include a drive gear meshed with the first spur gear and concentrically mounted on one end of a drive shaft with a worm gear mounted concentrically on an opposing end of the drive shaft. Rotation of the worm gear causes the spur gear and the drive gear to rotate and cause movement in the rack received into the cavity thereby separating or bringing together the modules as a result of the movement in the rack. 
     A worm can be mounted on a tubular extension protruding through the wall of a second module and engage the worm gear mounted concentrically on the opposing end of the drive shaft. A handle can also be connected to the tubular extension. In some embodiments, the handle can telescope from a housing of the second module to an operating position. 
     The connection device can also provide lost motion between the drive gear and the drive shaft. The lost motion can be sufficient to allow the rack to engage at least one gear tooth on the spur gear before rotation of the spur gear is restricted by the drive shaft. Lost motion can be provided, for example, by a cross pin secured to the drive shaft and engaging the drive gear at opposing surfaces formed into the drive gear to allow a predetermined angle of free rotation. A spring can also be included for maintaining the drive gear in a position allowing maximum lost motion before the gear motion is restricted. 
     Similarly, a method is provided for assembling modules on a mailing machine that includes setting a drive gear in a home position and manually aligning a tongue with a rack on a first module with a cavity having a drive gear on a second module. The rack can be operatively engaged with the drive gear. Turning a handle can rotate a worm mesh connected to the drive gear thereby causing the gear to rotate and move the rack. The setting of the drive gear can include a predetermined amount of lost motion associated with the drive gear. 
     Therefore it should now be apparent that the invention substantially achieves all the above aspects and advantages. Additional aspects and advantages of the invention will set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. Various features and embodiments are further described in the following figures, descriptions and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts. 
     FIG. 1 illustrates a perspective view of a modular mailing machine of the type in which the present invention may be utilized. 
     FIGS. 2 a  and  2   b  illustrate perspective views of basic module components that can be joined during the assembly of a mailing machine. 
     FIG. 3 a  illustrates a bottom up view of an embodiment of the present invention. 
     FIG. 3 b  illustrates a top down view of an embodiment of the present invention. 
     FIG. 4 illustrates a gear and a means for providing lost motion in relation to a drive shaft. 
     FIG. 5 illustrates a bottom up view of a tongue portion in relation to a cavity according to an embodiment of the present invention. 
     FIG. 6 illustrates a top down view of a cavity including gears and worm meshes in relation to a tongue portion, according to some embodiments of the present invention. 
     FIG. 7 illustrates flow of steps that can be completed while practicing the present invention. 
    
    
     DETAILED DESCRIPTION 
     The present invention includes apparatus and methods for assembling modules of a machine, such as, for example, a mailing machine. During assembly of various modules or other portions of a mailing machine, various modules are aligned and secured together. Embodiments of the present invention facilitate alignment of different modules being assembled into a mailing machine and securing of the modules in an assembled state. While the present invention will be described with respect to a mailing machine, it should be understood that the present invention is not limited and can be used with any type of machine. 
     Mechanisms utilized can facilitate mating of two modules with a rack included in one module and a gear included in another module. Once engaged, the gear can be turned to draw the rack in and also mate the corresponding modules. Assembly motion of a mailing machine can move a rack tangentially relative to a gear with which it will need to mate in order for the mailing machine to become assembled. The present invention also provides apparatus and methods to facilitate the rack engaging the gear without the teeth of the rack colliding with the teeth of the gear which can cause a jam instead of meshing. Jamming can be particularly problematic if the gear is unable to rotate and accommodate the rack motion, such as when the gear is connected to a worm gear. 
     For the purpose of this application, one or more teeth of a gear become “jammed” with one or more teeth on a rack when the apex or tip of a tooth, of the gear comes into contact with the apex of a tooth on the rack. A jam is generally opposed to “meshing” of a gear and a rack, wherein meshing occurs when the apex of a tooth on the gear is inserted into the gullet of a tooth on the rack or an apex of a tooth on the rack is inserted into a gullet on the gear. Generally, meshed teeth allow rotational movement of the gear and linear movement of the rack with which it is meshed. 
     Referring now to FIG. 1, there is seen a mailing machine generally designated by the reference numeral  10 . The mailing machine  10  includes two modules, a first module  101 , such as, for example, a metering module, which may or may not have a weighing functionality, and a second module  102 , such as, for example, a feeder-sealer module. The details of construction of these modules in relation to the operation thereof form no part of the present invention, and therefore are not described in full detail. It is sufficient for an understanding of the invention to note generally that the feeder-sealer module  102  includes a feeding area  12  into which a stack of envelopes is placed, and a suitable feeding mechanism separates the envelopes seriatim and feeds them through the feeder-sealer module  102  in which the envelope flaps are opened, the flaps are moistened and the envelope flaps are then closed and sealed. The envelopes then travel from this module to the metering module  101  in which they optionally can be weighed, the amount of postage for each envelope is calculated by a postage meter generally designated by the numeral  20 , and an appropriate postage indicia showing the postage is printed on the envelopes. The feed path along which the envelopes travel commences at the feeding area  12  on the feeder-sealer module  102 , extends through both modules  102  and  101 , and terminates at the discharge end  23  shown at the right side of the module  101  as viewed in FIG.  1 . It will be apparent, of course, that both modules  101  and  102  are covered with suitable top, front, rear and side housing panels so as to enclose and protect the operating components of the modules. 
     Referring now to FIGS. 2 a  and  2   b , perspective views of basic components included in the two modules of a mailing machine  10  according to the present invention are illustrated. Generally, module  101  can be assembled with module  102 . Components and mechanisms (not illustrated) mounted in the modules become properly aligned and positioned when the modules  101  and  102  arc assembled. To facilitate assembly of the first module  101  with the second module  102 , a tongue  103  can be formed into or attached to the first module  101  and a cavity  104  can be formed into, or attached to, the second module  102 . A manual portion of assembly can be accomplished by aligning the tongue  103  with the cavity  104  and inserting the tongue into the cavity  104 . Embodiments can include mechanical devices to assist in alignment of the tongue with the cavity, such as an alignment pin being received into a bushing, a lip on the tongue being received into a groove in the cavity, or other device. 
     Referring now to FIG. 3 a , a bottom up view of two exemplary modules of a mailing machine is illustrated, including a first spur gear  201  and a second spur gear  202 . The second spur gear  202  can be operatively engaged with the first spur gear  201  and act as a drive gear to cause movement in the first spur gear  201 . For purposes of this discussion, the second spur gear  202  will be referred to as the drive gear  202 . Movement can be initiated and controlled by a handle  211  which can be rotated by an operator. The drive gear  202  can be mounted on a drive shaft  207  which is operatively linked to the handle  211  such that rotation of the handle causes the drive shaft  207  and the drive gear  202  to also rotate. Rotation of the drive gear  202  can, in turn, cause the first spur gear  201  to rotate. 
     FIG. 3 b  illustrates a top down view of the same exemplary modules illustrated in FIG. 3 a . Embodiments can include the drive shaft  207  as illustrated connected to a worm gear  205  mounted concentrically on the end of the drive shaft  207 . A worm  206  can be operatively engaged with the worm gear  205 . The worm  206  can be concentrically mounted on one end of a tubular extension  204  which can protrude through the side, or housing, of the second module  102  and be attached to the handle  211 . 
     Rotation of the handle  211  can cause the tubular extension  204  to rotate and transfer the rotative movement to the second worm gear  206 . Rotation of the worm  206  will cause the worm gear  205  to rotate and also cause the drive shaft  207  on which the worm gear  205  is mounted to rotate. The drive shaft  207  carries the rotative movement to the drive gear  202 . The drive gear  202  is operatively engaged with the first spur gear  201 , wherein rotation of the drive gear  202  causes the first spur gear  201  to also rotate. 
     During assembly of the first module  101  with the second module  102 , a rack  203  mounted on, or formed into the tongue  103  can operatively engage the first spur gear  201  mounted within the cavity  104 . Once the rack  203  is operatively engaged with the first spur gear  201 , rotation of the first spur gear  201  will cause linear movement in the rack  203  and thereby cause the first module  101  and the second module  102  to move closer together or further apart depending upon the direction of the movement caused by the rotation. 
     Accordingly, embodiments can include assembly of a first module  101  and a second module  102  that is controlled by a gear train which can include the first spur gear  201 , the drive gear  202 , the drive shaft  207 , a worm mesh including the worm gear  205  and the worm  206 , the tubular extension  204  and the handle  211 . The worm  206  is attached to the handle via the tubular portion  204  which extends through a wall of the second module  102  and connects to the handle  211 . The first module  101  and the second module  102  can be fully assembled together by turning the worm  206  with the handle  211 . The worm mesh formed by the worm gear  205  and the worm  206  secures the position of first module  101  in relation to the second module  102  via the self-locking nature of a worm mesh. In addition, the worm mesh can provide mechanical advantage to facilitate overcoming mating forces of the modules  101  and  102 . 
     Some embodiments can include lost motion built into the gear train. In general, lost motion is the difference between the motion of a driver and that of a follower. As applied to the gear train, the drive shaft  207  is the driver and the first spur gear  201  is the follower. Lost motion includes a difference between rotative motion of the drive shaft  207  and rotative motion in the first spur gear  201 . For example, 180 degrees of lost motion allows the drive shaft  207  to turn 180 degrees before causing motion in the drive gear  202  and resulting motion in the first spur gear  201 . 
     Rotative motion in the drive shaft  207  is supplied by turning the handle  211 . The handle  211  is connected to the tubular portion  204  on which the worm  206  is mounted. As the handle  211  is turned, the worm  206  turns and creates rotational movement in the worm gear  205 , which is mounted on the drive shaft  207  and thereby causes motion in the drive shaft  207 . 
     Lost motion built into the gear train can be compensated for during initial rotation of the handle  211  attached to the drive shaft  207 , wherein an operator will turn the handle  211  through an arc of lost motion before causing movement in the gear train. In addition to facilitating gear alignment, lost motion can be useful, for example, to facilitate placing the handle  211  in a parked position. A parked position can include a cutout or keyed area formed into a wall of the second module  102  that secures the handle  211  from rotation and can help prevent accidental rotation. Some embodiments can include a handle  211  that can telescope out from the second module  102  into an operating position. 
     In another aspect, some embodiments can include a break away feature that prevents applying excessive force to any gear train components. For example, a break away can be built into the handle  211  to prevent an amount of torque above a threshold from being applied to the gear train via rotation of the handle  211 . 
     Referring now to FIG. 4, lost motion can be introduced into the gear train, for example, between the drive gear  202  and the drive shaft  207  that drives the drive gear  207  via a cross pin  311  contacting one or more cross pin stops  313 - 316 . The cross pin  311  can be inserted through a bore in the drive shaft  207  or otherwise coupled to the drive shaft  207 . The cross pin stops  313 - 316  can be positioned so that following a reversal in the direction of rotation of the drive shaft  207 , the cross pin  311  can be rotated through a predetermined arc of free movement before engaging a cross pin stop  313 - 316  in the new direction of rotation. 
     Reversal of rotation of the drive shaft  207  can therefore cause the cross pin  311  to rotate through a free movement area  317 - 318  until the cross pin  311  contacts one or two cross pin stops  313 - 316  which will be in the path of rotation. For example, as illustrated, if the drive shaft  207  is rotated in a clockwise direction the cross pin  311  will contact cross pin stops  313  and  315  simultaneously. If the direction of rotation of the drive shaft  207  is changed to a counter-clockwise direction, the cross pin  311  will travel through free movement area  317 - 318  and contact cross pin stops  314  and  316  simultaneously. 
     An amount of free movement area  317 ,  318 , which can be quantified as an arc  312 , will determine how many degrees of lost motion the gear train will provide. An arc should take into account the diameter of the cross pin  311 . Embodiments can include, for example, approximately 45 degrees of lost motion, 90 degrees of lost motion, 180 degrees of lost motion, or some other amount of lost motion. 
     Some embodiments can also include a means to return the cross pin  311  to a home position, or otherwise maintain the cross pin  311  in the home position, while the first module  101  and the second module  102  are separated. For example, a home position can include a position at a predetermined angle of rotation away from the drive gear  202  surface through which motion is transmitted. Some embodiments can include a predetermined angle that is calculated as, and approximately equal to (X+0.5)*(360/Ng), wherein X can be any whole number, and will typically be limited to 1 or 2 and Ng can be a number equal to the number of teeth on the drive gear  202 . Other angles may also be utilized. It is desirable for an angle utilized to facilitate placing the first gear  201  in a position favorable for engaging with a rack  203  incorporated into a first module during assembly with a second module  102  housing the first gear  201 . 
     A means to return the cross pin  311  to the home position can include, for example, a spring  310  situated to rotate the drive gear  202  through any available free movement area  317 - 318  when the first module  101  and the second module  102  are separated. The spring  310  can be secured with a spring coupling  309  or other means. 
     Referring now FIG. 5, details of the present invention are illustrated with an underside view of the cavity  104 , including a drive gear  202  mounted on a drive shaft  207  and a first spur gear  201  meshed or otherwise actively engaged with the drive gear  202 . A bottom up view of the tongue  103  is shown positioned to enter the cavity  104 . 
     Referring now to FIG. 6, details of the present invention are illustrated with a topside view of the cavity  104 , including a worm mesh comprising a worm gear  205  mounted concentrically on the end of the drive shaft  207  and a worm  206  operatively engaged with the worm gear  205 . The worm  206  can be concentrically mounted on one end of a tubular extension  204  which can protrude through the side  510  of the second module  102  and attached to the handle  211 . In addition, a topside view of the tongue  103  illustrates a rack  203  which will engage the first spur gear  201  as the tongue enters the cavity during assembly. 
     Referring now to FIG. 7, steps are illustrated which can be executed during implementation of inventive steps included in the present invention. At  610 , during assembly of disparate modules on a mailing machine, a drive gear  202  can be set in a home position that is favorable for engaging a rack  203  on a tongue  103  inserted into the cavity  104 . Setting in a home position can include rotating through an arc of lost motion, such as, approximately 45 degrees, 90 degrees, or 180 degrees, or some other arc, as discussed above. At  611  the tongue  103  on the first module  101  and the cavity  104  on the second module  102  can be aligned, such as by manually entering the tongue  103  into the cavity  104 . At  612  as the tongue  103  enters the cavity  104 , the rack  203  can be engaged with the first spur gear  201 . 
     At  613 , the handle  211  can be telescoped out into an operating position and at  614  turned to rotate the worm gear  205  in a direction which will cause the tongue  103  to move within the cavity  104  such that the movement will cause the tongue  103  to further enter the cavity  104  or become separated from the cavity  104 . Some embodiments can limit manual alignment so that the first module  101  and the second module  102  can be brought together or separated only by turning the worm mesh with the handle  211 . In these embodiments, manual alignment ends upon rack  104  engagement with the first spur gear  201 . At  615 , when the tongue  103  is brought into the cavity  104  to a point desired, the handle can be secured into the housing  510 . In addition, some embodiments can include lost motion in the gear train which facilitates alignment of the handle into a parked position secured in the housing. 
     In another aspect, some embodiments can include a break away feature incorporated into the handle which limits the amount of torque the handle can impart to the tubular extension and gear train and thereby prevent excessive forces to the gear train and other interface components. 
     The words “comprise,” “comprises,” “comprising,” “include,” “including,” and “includes” when used in this specification and in the following claims are intended to specify the presence of stated features, elements, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, elements, integers, components, steps, or groups thereof. 
     A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, an alignment pin or other mechanism can be utilized to further facilitate manual alignment. Components of the present invention can be formed from plastic, steel, aluminum, alloy or other material. In addition, although exemplary embodiments illustrated one rack  203  operatively engaged with the first spur gear  201 , some embodiments can include more than one rack  203  operatively engaged by additional spur gears or the drive gear  202 , the rack  203  can operatively engage a drive gear and the first spur gear can be omitted, or other design. Embodiments can include, for example, an additional rack  203  formed into the tongue  103  in a location that will operatively engage the drive gear  202  as the first module  101  and the second module  102  are assembled. Utilization of more than one rack engaged by more than one gear may be useful to maintain proper alignment of the modules  101  and  102  during assembly. Other variations relating to implementation of the functions described herein can also be implemented. Accordingly, other embodiments are within the scope of the following claims.