SKELETON WHEELS AND METHODS FOR ATTACHING WEBS THERETO

Abstract: A skeleton wheel (14) for a printing press has at least one support member (52) mounted axially along the leading or trailing edges (24,26) of an opening (22) extending the full axial width of the wheel, and to which a respective end of an anti-smear fabric web (12) can be attached. The support member (52) which may be an axially extending roller which is non-rotatably mounted on the wheel, permits limited axial movement, of the end of the web (12).

Description: This invention relates to skeleton or transfer wheels of the general type used in high speed multi-station printing presses and to methods for attaching webs thereto. In my US Patent No. 3,791,644 there is disclosed a skeleton wheel for use in a printing press to reduce marking and smearing of the printed surface of a sheet during conveying of the sheet between processing stations in the press. My US Patent No. 4,402,267 is directed to an improvement of the invention disclosed in my earlier patent, and specifically to a method and apparatus including the attachment of an anti-smear fabric to the support surface of a skeleton wheel. As disclosed in my US Patent No. 4,402,267 for proper operation, the anti-smear fabric must be loosely attached to the support surface of the skeleton wheel to permit and accommodate slight relative movement between the fabric covering and the wheel support surface when the printed sheet is supported and transferred by the wheel. As also disclosed in that patent, the fabric strips, such as double sided adhesive strips or fastening strips made under the trademark VELCRO, extending along the axial width of the wheel and disposed along in-turned flanges formed at the leading and trailing edges of the cylindrical supporting wheel surface. When the method and apparatus disclosed in my aforementioned US Patent No. 4,402,267 has been highly successful in use, it has been found that some printed sheet marking and smearing may occur in the immediate area of the leading and trailing edges of the wheel support surface, and particularly in the area of the leading edge. It has now been determined that such marking and smearing is caused principally by the manner in which the axial ends of the fabric are fastened to the wheel. With the use of fastening strips formed on in-turned flanges, as disclosed in my US Patent No. 4,402,267, the fabric extends over the leading and trailing edges of the wheel support surface in a generally taut condition, thereby restricting relative movement of the fabric in the area of the leading and trailing edges. Due to this taut condition, marking and marring of freshly printed sheets has occurred. An object of the present invention is to provide a skeleton wheel which reduces marking and marring of freshly printed sheets in the area of the leading and trailing edges of the wheel support surface, and to provide a method for attaching a web to such a wheel. According to one aspect of the invention, there is provided a method for attaching an anti-smear fabric web having leading and trailing ends to the support surface of a skeleton wheel of the type used in supporting and conveying printed sheets in a printing press and having an opening along the axial width defining a leading edge and a trailing edge of the support surface characterised by: providing a support member capable of limited axial movement within the opening adjacent the leading edge of the support surface; attaching the leading end of the web to the support member for limited axial movement therewith during use of the wheel; and extending the trailing end of the web around the support surface of the wheel and attaching the trailing end to the wheel within the opening. According to another aspect of the invention, there is provided a method for attaching an anti-smear fabric web having leading and trailing ends to the support surface of a skeleton wheel of the type used in supporting and conveying printed sheets in a printing press and having an opening along the axial width defining a leading edge and a trailing edge of the support surface characterized by: providing a first support member capable of limited axial movement during use of said wheel within the opening adjacent the leading edge of the support surface of the wheel; providing a second support member capable of limited axial movement during use of said wheel within the opening adjacent the trailing edge of the support surface; providing fastening means on each of said first and second support members; attaching one of said leading and trailing ends of said web to said fastening means of one of said first and second support members such that the attached end is movable with the support member; extending the other of said leading and trailing ends over the support surface; and attaching the other of said leading and trailing ends to said fastening means of the other of said first and second support members such that said other attached end is movable with the other support member. According to another aspect of the invention, there is provided a skeleton wheel for use in conveying a printed sheet having wet ink on one side thereof between successive processing stations in a printing press, the wheel having a generally cylindrical peripheral support surface for supporting the printed sheet, and an opening extending the axial width of the surface so that the support extends less than 360 degrees, the axial sides of the opening forming leading and trailing edges of the support surface, and a fabric web for attachment to the wheel to extend in overlying relation with the support surface between the leading and trailing edges, characterized by means coupled with said wheel and disposed within said opening for receiving at least one end of said web, said means being coupled with said wheel for limited axial movement relative thereto whereby said end of the web can move axially relative to the support surface together with said receiving means during use of said wheel. According to a further aspect of the invention, there is provided a reel assembly for use in attaching an end of an anti-smear fabric web along the axial width of a skeleton wheel of the type used in supporting and conveying printed sheets in a printing press and having an opening along the axial width defining leading and trailing edges, said reel assembly comprising: a pair of axially spaced support brackets disposed within the opening and attached to said leading edge of said wheel to project generallly radially inwardly adjacent the sides of said wheel; an axially directed bore formed through each of said brackets; a rod extending between said brackets and through each of said bores; a roller non-rotatably mounted on said rod for movement axially therealong, said roller having an axial width less than the axial distance between said brackets; and fastening means coupled to said roller for attaching the axial end of said fabric web to said roller. The fabric web is preferably attached at each end to a pair of substantially identical reel assemblies, one disposed adjacent the leading edge of the wheel support surface and the other adjacent the trailing edge. Each reel assembly preferably includes a roller to which the web is attached and which is coupled to the wheel to permit limited axial movement of the roller relative to the wheel during operation of the press. In this manner, the web is permitted to move in the area of the leading and trailing edge of the wheel thereby to reduce sheet marking and smearing in the areas of the leading and trailing edges. Each reel assembly preferably includes a pair of support brackets disposed adjacent the sides of the wheel and which releasably support a rod extending axially between the supports. The roller may be non-rotatably but slidably coupled to the rod, and be formed to have an axial length slightly less than the length of the rod between the brackets to permit axial movement of the roller along the rod between the limits of the brackets. Means are preferably provided to permit the rod to be selectively rotated within the brackets, and to attach the ends of the fabric web to the roller. To attach the web to the wheel, one axial end of the web, preferably the leading axial edge end, may be attached to the roller of the reel assembly adjacent the leading edge of the wheel. The trailing axial end of the web may then be extended over the wheel support surface and attached to the roller of the reel assembly adjacent the trailing edge of the wheel. The rods are then released for rotation from their support brackets and rotated to wind the fabric onto the roller until the proper web tension is achieved. Thereafter, the rods are resecured to their brackets to clamp the rods and rollers against rotation thereby maintaining the proper web tension over the wheel support surface. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention, and in which: Figure 1 is a perspective view of a skeleton wheel according to a preferred embodiment of the invention; Figure 2 is an enlarged cross-sectional view thereof taken along the line 2-2 of Figure 1, showing a fabric web attached to the skeleton wheel, and illustrating, in broken line the wheel attached to a shaft of a printing press; Figure 3 is an enlarged fragmentary side view, partly in cross-section, of the wheel of Figure 1 and as seen in the direction of the arrows 3-3 of Figure 1; and Figure 4 is a reduced fragmentary plan view, partly in cross-section, as seen in the direction of the arrows 4-4 of Figure 3. As shown in the exemplary drawings, the present invention is embodied in a new and improved method and apparatus 10 for attaching an anti-smear fabric net or web 12 (see Figure 2) to a skeleton wheel 14 of the type used to support and convey printed sheets between processing stations in high speed, multi-station printing presses. In this instance, the skeleton wheel 14 is of the general type disclosed in US Patent 3,791,644, and includes an inner, generally cylindrical wall 16 and an outer generally cylindrical support surface 18 extending between axially spaced sides 20, and an opening 22 extending along the axial width of the wheel so that the inner wall and outer cylindrical support surface extend less than 360 degrees about the wheel axis. The opening 22 is provided to facilitate operation of gripper apparatus (not shown) normally positions adjacent the skeleton wheel 14 in a printing press, and defines a leading axial edge 24 and a trailing axial edge 26 of the outer cylindrical support surface 18. To support the skeleton wheel 14 in a printing press, shaft attachment brackets 28 project radially inwardly from the inner cylindrical wall 16, there being three such brackets herein provided in spaced relation along the axial width of the wheel with each bracket being substantially identical to the others. In this instance, each shaft bracket 28 includes three similar struts 30 projecting radially inwardly from the inner wall 16 and terminating in a U-shaped mount 32 which is dimensioned to receive a shaft 34 (shown in broken line section in Figure 2) suitably journaled for rotation in the press. Mating key-ways 36 and 38 are formed, respectively, in the shaft 34 and closed end portion of the mount 32 and into which a key 40 is placed to lock the wheel 14 on the shaft against relative rotation. To hold the shaft 34 in position in the bracket, a plate 42 is supported in grooves 44 formed in the bracket adjacent the open end of the bracket to overlie the shaft, and a bolt 46 is threaded through the plate to engage the shaft and securely, but releasably wedge the shaft in position in the bracket. As seen in figure 2, the outer cylindrical wall 18 is provided with a suitable coating 48 which may be of the type disclosed in my aforementioned US Patent 3,791,644 or may be of the type described in my US Patent 4,402,267. The structure of the skeleton wheel 14 thus far described is generally similar to the skeleton wheels described in my aforementioned US Patents 3,791,644 and 4,402,267, and attention is directed to those patents for further details concerning the operation of the skeleton wheel or cylinder in a printing press. The fabric web 12 is disposed over the coating 48 to extend substantially the full axial width of the wheel 14, as well as from leading edge 24 to the trailing edge 26, and is preferably of the type disclosed in my aforementioned US Patent 4,402,267. While the fabric web 12 as described in my aforementioned US Patent 4,402,267 successfully prevents smearing or marking of a printed sheet, the fabric web does become soiled after prolonged use and must be either periodically replaced or cleaned. Moreover, it may be necessary to periodically adjust the tension in the fabric web 12 to ensure proper operation as the fabric web must remain relatively loosely disposed over the outer cylindrical surface 18 to permit slight web movement during use. In accordance with the illustrated embodiment of the present invention, the method and apparatus 10 permit the fabric web 12 to be readily and easily removed, installed, and adjusted for proper tension over the outer cylindrical surface 18 of the wheel 14, and operate in a reliable manner to provide a relatively trouble free and quickly used means for attaching the web to the wheel. Moreover, the apparatus 10 is relatively inexpensive to manufacture and simple in design yet highly effective in use. The ends of the fabric web 12 are attached to a pair of substantially identical reel assemblies 50 with one reel assembly being disposed to extend along the axial width of the wheel 14 adjacent the leading edge 24, and the other extending along the axial width the wheel adjacent the trailing edge 26. Each reel assembly 50 includes a cylindrical roller 52 to which the axial end of the fabric web 12 is attached, and which is coupled to the wheel 14 in such a manner that limited axial movement of the roller is permitted during operation of the wheel in the press, thereby to permit the fabric web to move slightly in the area of the leading and trailing edges 24 and 26 of the cylindrical support surface 18. More specifically, each roller 52 is slidably mounted on a central axial rod 54 between a pair of spaced support brackets 56 disposed adjacent the sides 20 of the wheel 14 and which are secured by any suitable means, herein by welds 58 (see Figure 3), to project generally radially inwardly from the inner cylindrical wall 16. Each support bracket 56 has an axially directed bore 60 of circular cross-section through which the end of the rod 54 extends, and is provided with an adjustable bolt 62 threaded through a cooperatively threaded hole 64 formed in the bracket to project into the bore and engage the rod. To slidably mount each roller 52 to its rod 54, yet prevent rotation of the roller relative to the rod, the rod herein has a hexagonal cross-section and extends through a pair of end plugs 66, herein formed of plastic, having corresponding hexagonal shaped central openings 68, and which are attached, herein by dimples 70 (see Figure 4), within respective ends of the roller. The axial width of each roller 52 is dimensioned to be slightly less, preferably on the order of 6.3 to 38 mm (one quarter to one and one-half inches), depending on the size of the press, than the axial distance between the support brackets 56 so that when the rod is secured in position in the brackets, the roller is free to slide axially along the rod within the limits of the brackets. To mount the axial end of the fabric web 12 onto each roller 52, a suitable fastening means 72, such as a double sided adhesive strip or a fastening strip of the type made under the trademark VELCRO, is provided along the length of the roller. Preferably, the fastening means 72 is provided with a centerline mark 74 midway between the axial ends of the roller 52 to form a reference mark for quick attachment of the fabric web 12 to the roller, the web preferably also having a centerline mark formed on each axial edge between the sides. To install the fabric web 12 on the roller 52, the adjustable bolts 62 of each bracket 56 are threaded out of engagement with the rods 54, thereby freeing the rods for rotation within the bores. One axial end, preferably the leading edge end, of the fabric web 12 is then aligned so that the midpoint of its axial width coincides with the centerline mark 74 of the fastening means 72 and then is pressed downwardly along the fastening means whereby the web is attached to the fastening means of its roller 52. The other axial end of the web 12 is then directed around the outer cylinder support surface 18 of the wheel 14 and fastened to the fastening means 72 of the other roller 52 by similarly aligning the axial width midpoint of the web with the corresponding centerline mark 74 of the fastening means and pressing the web into place. Thereafter, the rod 54 and roller 52 of each reel assembly 50 is rotated in its brackets 56 until the proper tension of the fabric web 12 over the outer support surface 18 of the wheel 14 is obtained. The adjustable bolts 62 are then threaded into engagement with the rods 54, thereby locking the reel assemblies 50 against rotation. This then maintains the proper tension in the fabric web 12 during operation of the press, yet, since the rollers are slidably mounted on the rods 54, permits limited axial movement of the web, particularly in the areas of the leading and trailing edges 24 and 26 of the wheel 14. Should it become necessary to adjust the tension of the web 12 during use, all that needs to be done is to stop the press, release the rod 54 of one of the reel assemblies 50 by unthreading the adjustable bolts 62, and then rotating the rod and its roller 52 until the proper tension has been obtained. The adjustable bolts 62 may then be rethreaded into engagement with the rod 54 and the press restarted for continued operation. From the foregoing, it should be apparent that the apparatus 10 of the present invention permits a fabric web 12 to be readily and easily removed, installed, and adjusted for proper tension over the support surface 18 of a skeleton wheel 14, and provides a means for permitting limited movement of the fabric web in the immediate areas of the body and trailing edges, 24 and 26, respectively, of the wheel thereby to reduce sheet marking in these areas during use. The present invention thus provides a method and an apparatus which permits an anti-smear fabric web to be readily and easily removed, installed and adjusted for proper tension over the support surface of a skeleton wheel of the type used to support and convey printed sheets between processing stations in a high-speed, multi-station printing press. The apparatus of the invention provides a relatively trouble-free and quickly used means for attaching the web to the wheel, and is relatively inexpensive to manufacture and simple in design yet high effective in use. A variety of modifications and improvements to the invention described herein are believed to be apparent to one skilled in the art. Accordingly, no limitation on the invention is intended, except by way of the appended claims.

Claims: A method for attaching an anti-smear fabric web (12) having leading and trailing ends to the support surface (18) of a skeleton wheel (14) of the type used in supporting and conveying printed sheets in a printing press and having an opening (22) along the axial width defining a leading edge (24) and a trailing edge (26) of the support surface (18) characterized by: providing a support member (52) capable of limited axial movement within the opening (22) adjacent the leading edge (24) of the support surface (18); attaching the leading end of the web (12) to the support member for limited axial movement therewith during use of said wheel; and extending the trailing end of the web (12) around the support surface (18) of the wheel and attaching the trailing end to the wheel (14) within the opening (22). A method according to claim 1 further including providing a second support member (52) capable of limited axial movement within said opening (22) adjacent said trailing edge (26) of said support surface (18) and attaching said trailing end to said second support member (52) for limited axial movement therewith. A method for attaching an anti-smear fabric web (12) having leading and trailing ends to the support surface (18) of a skeleton wheel (14) of the type used in supporting and conveying printed sheets in a printing press and having an opening (22) along the axial width defining a leading edge (24) and a trailing edge (26) of the support surface (18) characterized by: providing a first support member (52) capable of limited axial movement during use of said wheel within the opening (22) adjacent the leading edge (24) of the support surface (18) of the wheel (14); providing a second support member (52) capable of limited axial movement during use of said wheel within the opening (22) adjacent the trailing edge (26) of the support surface (18); providing fastening means (72) on each of said first and second support members (52); attaching one of said leading and trailing ends of said web to said fastening means (72) of one of said first and second support members (52) such that the attached end is movable with the support member; extending the other of said leading and trailing ends over the support surface (18); and attaching the other of said leading and trailing ends to said fastening means (72) of the other of said first and second support members (52) such that said other attached end is movable with the other support member. A method according to any one of the preceding claims in which a reel assembly (50) provides the or each support member (52). A method according to claim 4 in which a roller is provided as the or each support member (52). A method according to claim 4 or 5 when dependent on claim 3 further including the step of adjusting the tension in said web (12) by reeling said one of said leading and trailing ends onto the relevant reel assembly (50) after attachment of said other of said leading and trailing ends to the other reel assembly (50). A method according to claim 4 or 5 when dependent on claim 3 further including the step of adjusting the tension in said web (12) by reeling said other of said leading and trailing ends onto the relevant reel assembly (50) after attachment thereof to the associated fastening means. A method according to claim 4 or 5 when dependent on claim 3 further including the step of adjusting the tension in said web by simultaneously reeling both ends onto respective reel assemblies (50). A reel assembly for use in attaching an end of an anti-smear fabric web (12) along the axial width of a skeleton wheel (14) of the type used in supporting and conveying printed sheets in a printing press and having an opening (22) along the axial width defining leading and trailing edges, said reel assembly comprising: a pair of axially spaced support brackets (56) disposed within the opening and attached to said leading edge (24) of said wheel (14) to project generally radially inwardly adjacent the sides of said wheel; an axially directed bore (60) formed through each of said brackets; a rod (54) extending between said brackets and through each of said bores (60); a roller (52) non-rotatably mounted on said rod (54) for movement axially therealong, said roller (52) having an axial width less than the axial distance between said brackets (56); and fastening means (72) coupled to said roller (52) for attaching the axial end of said fabric web to said roller. A reel assembly as set forth in claim 9 further including means (62,64) for releasably securing said rod (54) within said bores. A reel assembly as set forth in claim 10 wherein said releasable securing means comprises a bolt (62) threaded through each of said brackets (56) and projecting into said bores (60) for engagement with said rod (54). A reel assembly as set forth in claim 9, 10 or 11 wherein said rod (54) has a polygonal cross-section and said bores (60) each have a generally circular cross-section. A skeleton wheel for use in supporting and conveying printed sheets between processing stations in a printing press and having an opening (22) along the axial width defining a leading (24) and a trailing edge (26) characterised by: a pair of reel assemblies (50) disposed within the opening (22) and extending substantially the full axial width of the wheel, one of said reel assemblies (50) being located adjacent the leading edge (24) of the wheel and the other along the trailing edge (26) thereof, each of said reel assemblies including: a pair of spaced support brackets (56) attached to the wheel and projecting generally radially inwardly therefrom adjacent respective opposite sides of the wheel; an axially directed bore (60) of generally circular cross-section extending through each of said brackets; a rod (54) extending between said brackets (56) and through the bores (60); a roller (52) non-rotatably mounted on said rod (54) for movement axially therealong, said roller (52) having an axial width less than the axial distance between said brackets (56) whereby said roller can move axially along said rod (54) between the limits of said brackets (56); and means (62,64) for releasably holding said rod within said bores (60) and preventing relative rotation of said rod within said bores. A wheel as set forth in claim 13 further including fastening means (72) coupled to said roller (52) for attaching a fabric web thereto. A wheel as set forth in claim 13 or 14 wherein said releasable means comprises a bolt (62) threaded through each of said brackets (56) into said bores (60). A wheel as set forth in any one of claims 13 to 15 wherein said rod has a polygonal cross-section. A wheel as set forth in claim 16 wherein said roller (52) has a generally cylindrical outer surface and is mounted on said rod (54) by a pair of end caps (66) secured to said roller and having polygonal openings through which said rod projects. A skeleton wheel for use in conveying a printed sheet having wet ink on one side thereof between successive processing stations in a printing press, the wheel having a generally cylindrical peripheral support surface (18) for supporting the printed sheet, and an opening (22) extending the axial width of the surface so that the support surface extends less than 360 degrees, the axial sides of the opening forming leading and trailing edges (24,26) of the support surface (18) and a fabric web (12) for attachment to the wheel to extend in overlying relation with the support surface (18) between the leading and trailing edges (24,26) characterised by: means (52) coupled with said wheel and disposed within said opening (22) for receiving at least one end of said web (12) said means being coupled with said wheel for limited axial movement relative thereto whereby said end of the web can move axially relative to the support surface together with said receiving means during use of said wheel. A wheel as set forth in claim 18 wherein said receiving means comprises: a rod (54) extending the full axial width of said opening (22); means (56) adjacent opposite axial ends of said opening (22) for attaching said rod to said wheel; and a roller (52) non-rotatably mounted on said rod (60) said roller having an axial length less than the axial length of said rod (54) and mounted on said rod for limited axial movement along said rod. A wheel as set forth in claim 19 wherein said means for attaching said rod (54) to said wheel comprises a pair of axially spaced support brackets (56) having axially directed bores (60) formed therethrough, said rod (54) projecting through said bores (60). A wheel as set forth in claim 20 further including means for releasably securing said rod (54) within each of said bores (60) to prevent rotation of said rod within said bores. A wheel as set forth in claim 21 wherein said releasable securing means comprises a bolt (62) threaded through each of said brackets (56) and projecting into said bores for engagement with said rod.

Inventors: DEMOORE, HOWARD W.
Applicants: DEMOORE, HOWARD W.
Application year: 1987
Main classification: B41F13
IPC codes: B41F27, B41F13, B41F21, B41F22