Abstract:
The present invention relates to locking and locating cylindrical components or roller sleeve assemblies on a support shaft. The locking feature is an anti-rotation device that prevents rotation of the roller assembly or sleeve assembly on the support shaft. The locking feature permits axial location of the component or sleeve to a pre-determined position as desired. A pair of over-running clutches or one-way clutches is used to facilitate the feature. The clutches are assembled to a receiving bore in the component or sleeve so that they are able to lock on the support shaft in reverse directions, thereby preventing rotation of those parts on the support shaft.

Description:
BACKGROUND 
     The present invention relates to the assembly of rotatable shafts and the components that are mounted upon them. The support shafts that hold cylindrical components used for conveying articles have to be located in an axial relationship to the support frames or members that hold them. Typically, the axial relationship of such cylindrical components or assemblies that are used for conveying objects are aligned with other similar components in machinery. The tolerance buildup of the components from one assembly to another may mean that the alignment is actually mis-aligned, thereby causing problems in the conveying or transport of the articles that are moving on them. In the past, there have been numerous ways to overcome this problem, such as machining a flat upon the shaft, and then machining the mounted cylindrical hardware to fit a setscrew or other locking member to attach to the flatted shaft. The machining of the shaft is expensive and labor intensive, as is applying the setscrew or other locking device. In addition, a setscrew design tends to pull the inner portion of the part being added to the support shaft to one side, thereby creating an out of round assembly. Also, burrs on the shaft may present further problems in disassembling or reassembling the shaft components. 
     Another way of locating such assemblies or cylindrical components is with the use of e-clips, or e-rings. The use of a tri-lobe or d-shaped shaft will fit the components being added with a similar designed aperture; however, there will be an undesired amount of free play between the shaft and the added components. This is not tolerable in critical transport or conveying situations where articles are expected to arrive at scheduled locations at particular times and increments of time. So, this prior art design is labor-intensive, requiring lathe set-up to machine grooves in the support shafts, and at assembly, installing the e-clips upon the shaft. In addition, there may be reliability problems associated with the concentricity, and expected transport results from this type of assembly. There may be a further complication unless due care is taken in the design of the support shaft since cutting grooves into the shaft may affect a stress condition, and an unpredictable failure, especially with the application of heavy loading upon the cylindrical member and its support shaft. 
     For these reasons, the present invention has evolved, and will eliminate assembly and tolerance problems related to concentricity, axial positioning of the added shaft components, and stress related failures. There are no grooves required in the support shafts with the use of the principles of the present invention, and the assembly of the cylindrical components on a support shaft is simplified and reliable. In addition, there are no setscrews, or machining of the support shaft, other than those required for automatic lathe processing. 
     FIELD OF THE INVENTION 
     The present invention may be utilized in all sorts of conveying machinery where there are roller assemblies mounted on support shafts, that are in turn supported in frames or support structure of the machinery. The present invention is designed to provide a highly accurate concentric assembly of components added to transport or conveying shafting where the support shaft rotates with the assembly attached. The present invention eliminates the need for cutting grooves in the support shafts or machining flats or other locating areas on the mounting or support shafts. The present invention also eliminates the need to apply devices such as e-rings or e-clips to then locate the assembly along a specific axial position on the shaft. This is particularly useful in high-speed paper conveying machinery, or other equipment that requires highly accurate timing and location of the transport devices to insure reliability. 
     SUMMARY OF THE INVENTION 
     The present invention concerns locking and locating cylindrical components or roller sleeves on a support shaft to facilitate anti-rotation of the components or sleeves on the shaft. The cylindrical components are typical such as conveying rollers or transport rollers that are manufactured as sleeve assemblies utilized to move and convey articles along a transport path. The locking and locating feature is an anti-rotation device that is accomplished through the use of at least one pair of over-running clutches or one-way clutches that are assembled into a prepared cavity located along the axis of the cylindrical component. The axial cavity may be a bore, or concentric bores located at both axial ends of the cylindrical component. Each over running clutch or one-way device is pressed into the cavity at either end of the cylindrical component so that each clutch faces an opposite direction. When the cylindrical component or roller sleeve is installed on the support shaft, the components of the over running clutches or one-way devices lock against the support shaft and each other, thereby providing an assembly that is rotatable as one unit; the cylindrical component further being axially positionable to a predetermined location on the support shaft. 
     The above background and brief description of the advantages of the present invention will be apparent upon consideration of the following detailed description when taken in conjunction with accompanying drawings. In the accompanying drawings, like reference characters refer to like parts throughout, and in which: 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a document transport assembly where the present invention is utilized. 
     FIG. 2 is an exploded isometric view of the components utilized in the assembly of FIG.  1 . 
     FIG. 3 is an isometric view of the roller assembly utilized in the transport assembly of FIG.  1 . 
     FIG. 4 is a section view of an alternative roller assembly used in the transport assembly of FIG.  1 . 
     FIG. 5 is an isometric view of the roller assembly of FIG. 4 without the support shaft. 
     FIG. 6 is an isometric view of the roller assembly of FIG. 4 with the support shaft. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, there is shown an isometric view of a document transport assembly  10 . This is a typical transport assembly used as an example as it may be utilized in Pitney Bowes Inserting Products that have vacuum assisted transport systems. The document transport system  10  illustrated is used to transport envelopes, and in other portions of Pitney Bowes inserting products to move sheets of paper of all sizes and types. The transport system  10  is designed to be positioned in a (not shown) main machine structure that can accommodate many similar such transport units. The present invention relates to how the supporting transport rollers are mounted for rotation as a unit, and axially positioned for supporting for example, sets of belts or other conveying instruments. The present drawings and illustrations are one example of how the present invention may be applied to conveying equipment. Such equipment may consist of rollers supporting belts as shown, or may consist of transport rollers alone. In either case, the present invention has utility to solve the problems described in the background of this patent application. 
     Referring to FIG. 2, there is shown a machined support frame  14 . The support frame  14  is designed to be mounted on the main machine structure referred to earlier, and a series of mounting apertures  18  will accommodate the necessary mounting hardware to do so. The support frame  14  has a bearing support ear  14   a  and  14   b,  each having a suitable ball bearing  14   c  and  14   d  (or ball bearing equivalent) pressed into the support ear  14   a  and  14   b  respectively. 
     Referring now to FIG. 3, there is shown an isometric view of a roller sleeve  20  as removed from the transport assembly  10 . The roller sleeve  20  is typical of such roller sleeves that are used in conveyor equipment, and in the present case is used to support a plurality of conveyor belts  22  (FIG.  1 ). (Some roller assemblies or roller sleeves have built in crowns that track the conveying belts in a desired lateral position). 
     The Anti-Rotation Feature 
     There is a first support element  24  (over running clutch) pressed into an end cavity (bore)  20   a  of the roller sleeve  20 . There is a second support element  26  (over running clutch) pressed into an opposing end cavity  20   b  of the roller sleeve  20 . It will be noted that the cavity  20   a  and  20   b  are one and the same of an axial bore of the roller sleeve  20 . Alternatively this design may be such that the end cavity  20   a  and  20   b  are of larger diameter, smaller diameter or the same as shown with regard to the axis of the roller sleeve  20 . (This will depend upon the size of the over running clutch selected, as well as the physical design of the roller sleeve). The concentricity of the diameters of the cavity  20   a  and  20   b  are very close in tolerance limits (if they are diameters different than that illustrated as a bore) which affords the greater benefit of accuracy in rotation of the roller sleeve  20 . The first and second support elements  24  and  26  (over running clutches) referred to are typical of those manufactured by the Torrington Manufacturing Company. An example of an over running clutch is shown in U.S. Pat. No. 3,994,377 to Elmore for OVERRUNNING CLUTCH RETAINER AND ROLLER ASSEMBLY. 
     Referring once again to FIG. 3, the roller sleeve  20  is shown with the first and second support elements  24  and  26  installed or pressed into the end of the principal roller section. The support elements  24  and  26  are flush with an end  20   f,  and  20   g  respectively of the roller sleeve  20  to afford the greatest possible length of fit with respect to the end cavity  20   a,  and opposing end cavity  20   b  respectively. The first support element  24  is installed so that the locking rollers internal to the Torrington over running clutch will lock on a shaft  34  once the shaft  34  is inserted into the support element  24 . This means that if only the first support element  24  were installed by itself into the roller sleeve  20 , the roller sleeve  20  could rotate in a CW direction  36  as indicated by the (Clockwise) arrow. (This may depend upon the assembly instructions of the over running clutch supplier). The second support element  26  is inserted into the opposing end cavity such that it is 180 degrees reversed from the first support element  24 . Once again, if only the second support element (over running clutch) were inserted into the opposing end cavity  20   b,  the roller sleeve  20  would be able to rotate in the direction  36 . However, once both the first support element  24  and the second support element  26  are both inserted into their respective end cavities  20   a,  and  20   b,  the roller cage inside of the over running clutch in each case is reversed, and with the insertion of the shaft  34  will lock against any rotation attempted upon the roller sleeve  20 . 
     It is possible to slide the shaft  34  along the length of the roller sleeve to a pre-determined axial position. The shaft  34  should be aligned with the first and second support elements  24  and  26  so that the major outside diameter of the shaft  34  is supported by the aforementioned support elements. The shaft  34  is formed with a taper  34   a,  which is used to assist in the insertion process. The taper may be a radius, or other shallow form that will assist the assembly process, either of which or some variation in between will allow the shaft  34  to be inserted through both of the aforementioned support elements  24  and  26 . A taper of approximately 2 to 5 degrees is sufficient to permit assembly of the shaft  34  into the new bore of the roller  20  as established by the first and second support elements  24  and  26 . The shaft  34  is formed of suitable case hardenable steel. Following guidelines of assembly of the over running clutch designs, a Rc hardness of between 55-60 is suitable to insure that the roller elements of the over running clutch work properly in locking with the shaft. 
     Referring back to FIG. 1, it will now be recognized that insertion of the shaft  34  through the Machine support frame  14  in the bearing support ear  14   a  and  14   b  bearings as described will provide a complete assembly in the area of the document transfer assembly as described. Typically, in most transport assemblies or conveyor assemblies there has to be a second support roller or shaft. In the present case there is an end structure, that is a second shaft support structure (not shown), having the same assembly technique for locating and supporting a second roller sleeve and the opposite ends of the conveying belts  22 . The benefit of this technique becomes apparent when the shaft  34  is inserted and the roller sleeve  20  is now trapped and located between the bearing support ears  14   a  and  14   b  respectively. Not shown, there could be suitable washers or spacers inserted between the inside portions of the ears  14   a  and  14   b  to help position the roller laterally (axially) to a pre-determined point. Other benefits include the elimination of installing retaining rings, e-clips or other hardware that require machining of the support shaft, and possible installation of set-screws. Setscrews are notorious for backing off due to vibration and rapid start/stops of conveying assemblies. 
     Description of an alternative embodiment of the present invention as a anti-rotation device: 
     Referring to FIG. 4, a cross sectional view of another roller assembly  40  is shown. The roller assembly has a bore  42  that is concentric to an outside diameter  40   a  of the roller assembly  40 . There is a pair of support elements  44  and an opposing pair of support elements  46  each consisting of a first support element  44   a,  a second support element  44   b,  a first support element  46   a,  and a second support element  46   b.  The support elements  44   a,    44   b,    46   a,  and  46   b  are assembled into the bore  42  of the roller assembly  40  in the following way. Second support element  44   b  such that if assembled alone would permit rotation of the roller assembly on a support shaft  48  in a direction  50  (FIG.  5 ), providing no other support elements are also inserted into the bore  42 . When the first support element  44   a  is inserted into the bore  42 , the pair of support elements  44  will prevent rotation of the roller assembly  40  on the support shaft  48 . This is the same for the pair of opposing support elements  46 , when the first support element  46   a,  and the second support element  46   b  are inserted into the bore  42 . The roller assembly  40  is shown as it would be located between the bearing support ear  14   a  and  14   b  in the prior embodiment. The assembly of additional support elements will insure that the roller assembly is locked on the shaft  50  for example where there is rapid, high energy start/stop conditions in the transport that would ordinarily shake a setscrew or other fastening member loose from the support shaft. 
     In FIG. 4, there is shown a thrust washer  52  and  54 , used to help axially locate the roller assembly  40  between the support ear  14   a  and  14   b.  Other suitable washers, rings, helical springs or conical springs may be used to help justify the roller assembly  40  to one side or the other of the support frame  14  as may be desired. FIG. 6 is a representative assembly of the roller assembly  40  and the support shaft  48 . It will be noted that the shaft  50  has a similar tapered end to that described in the previous embodiment and the shaft  34 . 
     There may be other combinations considered that combine roller assemblies, support shafts and support elements utilizing one way clutches or over running clutches in the manner described in the present specification. These alternate combinations will be known by those skilled in the art as can be applied to the system as described in the embodiments described in this specification, and it would be space consuming in the present specification to provide such other combinations that will be known and used by those skilled in the art. Therefore, the preceding detailed specification, drawings, and description of same sets forth examples of how the combination of reverse acting devices such as over running clutches or one way clutches may be applied to conveying rollers or their substitutes. 
     Further advantages and modifications will readily occur to those skilled in the art. Therefore, in its broader aspects, the invention is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims.