Abstract:
The present invention relates to a device for replacing elements of a product delivery fan wheel which is rotatably mounted. The fan wheel has a plurality of fan blades which include attaching devices for replaceably mounting fan blade tips on the fan blades.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a product delivery apparatus, such as a fan wheel or the like of a printing press, having replaceable elements. 
     BACKGROUND OF INVENTION 
     U.S. Pat. No. 4,357,008 discloses a creel assembly for use in a business forms delivery apparatus wherein individual business forms are received between adjacent spirally formed fingers of a plurality of aligned creel assemblies. Business forms are inverted from a “face-up” to “face-down” position. 
     U.S. Pat. No. 4,925,179 discloses a delivery fan with undulated fan pockets. The fan includes two sets of blades. The blades of one set are equally spaced apart axially and define one side of each pocket. The blades of the other set are equally spaced axially define the other side of each pocket. The blades of the two sets have surfaces for engaging opposite sides of a signature and for deforming the signature into undulations extending in a direction transverse to the direction of movement of the signature. Due to frictional contact between the signature and the surfaces of the pocket, the signature is slowed down to minimize buckling or bouncing of the signature in the respective pocket. 
     U.S. Pat. No. 5,083,768 discloses a device for reducing the velocity of impact of printed products in the base of a delivery paddle wheel of printing presses. A shaft having cam plates with cams mounted thereon is assigned to a delivery paddle wheel. The cams catch the printed products arriving in the delivery paddle wheel at their trailing end and decelerate them. The shaft supporting said cams can be set according to different lengths of the printed products. 
     U.S. Pat. No. 5,180,160 shows a delivery device in a folding apparatus of a rotary printing press. The delivery device includes a fan wheel or several fan wheels disposed next to one another. The fan wheels are formed of individual fan blades between which fan wheel pockets are provided. Leading edges of the fan blades have a first profile and trailing edges of the blades have a second profile. 
     U.S. Pat. No. 5,112,033 discloses a folder apparatus for a web-fed printing press. There are two fan arrangements, each having a plurality of fan blades disposed parallel to the common axis of each other. The fan blades of each fan arrangement have tips located at a circumference of the respective fan arrangement in a common plane, with circumferences of the fan arrangements intersecting one another. A device is provided on the fan arrangements for preventing a collision of the respective fan blade tips. 
     SUMMARY OF THE INVENTION 
     Given the state-of-the-art, it is an object of the present invention to provide for replacing fan tips. 
     Furthermore, it is an object of the present invention to allow for an adjustment of the fan blade tip properties with regard to signature delivery requirements. 
     According to the present invention, exemplary embodiments of a product delivery apparatus having replaceable elements include: 
     at least one fan wheel which is rotatably mounted, 
     a plurality of fan blades included on said at least one fan wheel, and 
     attaching devices included on each of said fan blades for mounting replaceable fan blade tips to said fan blades. 
     Thus, an easy exchange of parts of the fan wheels is feasible without dismounting the fan wheel arrangement in its entirety. The solution allows for retrofitting of fan tips with fan blade tips having a different curvature or being of different material. Damaged fan tips due to wear can easily be exchanged. Furthermore, by mounting fan blade tips of different material a rebalancing of fan wheel arrangements can easily be achieved. 
     According to the invention not only attaching devices are provided but also abutting surfaces for aligning (for example, centering) fan blade tips relative to the respective fan blade ends. The attaching devices include snap-on devices of apertures and clips, or fastening screws, or cams of a certain shape engaging corresponding recesses of fan blade ends or blade tips or vice versa. 
     The replaceable fan blade tips can be made of any material, including, but not limited to, plastic (for example, plastic formed using any known processing technique including, but not limited to, injection molded plastic or structural foamed plastic), steel, aluminum or composites. These materials, can also be coated or plated with other materials, if they fulfill determining factors in tip material selection such as strength, friction characteristics, manufacturing method and tip configuration. 
     There are not only attaching devices provided on said replaceably mounted fan blade tips but also aligning means, such as centering pins or abutting surfaces. The shape and the orientation of said abutting surfaces prevent the fan blade tips from being mounted in a wrong orientation with regard to the sense of rotation of said fan wheel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments and methods of operation of the invention, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplary embodiments when read in connection with the accompanying drawings wherein: 
     FIG. 1 shows a schematic view of a folder having two fans partially overlapping each other&#39;s envelope curve; 
     FIGS. 2,  2   a  and  2   b  show an exemplary embodiment of a snap-on replaceable fan blade tip; 
     FIG. 3 shows an exemplary fan blade end section; 
     FIG. 3 a  shows an exemplary fan blade tip molded with foamed material, such as structural foamed plastic; 
     FIG. 3 b  shows a view of an exemplary fan blade tip molded with injection molded plastic; 
     FIG. 4 shows an exemplary fan blade end section; and 
     FIGS. 4 a  and  4   b  show exemplary embodiments of fan blade tips which can be mounted on fans rotating in opposite directions. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 shows a schematic view of an exemplary embodiment of product delivery device, represented as a folder having two partially overlapping fan wheels for transporting material. 
     A folder  1  includes a former  2  for leading a material, such as longitudinally folded continuous web of material, into upper draw rollers  3 . After passing the upper draw rollers  3 , the web enters lower draw rollers  4  and is subsequently conveyed via guide rollers  5  to a cutting cylinder  6  which severs samples from said continuous web of material. The samples are conveyed by a left lead-in tape  7  and a right lead-in tape  8  into fan-pockets  13  of two fans  11 ,  12 , respectively. The circumferences of said fans  11 ,  12  constitute envelope curves which partially overlap each other. Thus, single samples are alternately led into every other one of the fan pockets  13  of said fans  11 ,  12 . Each fan pocket  13  is formed between adjacent fan blades  14  of said fans  11 ,  12 . Below said fans  11 ,  12 , a conveying means, such as any known sample conveyor, are assigned to each of said fans for delivering said samples to further post press equipment. 
     As mentioned previously, the replaceable fan tips can be made of any material including, but not limited to, plastic, metal or composites. For example, replaceable fan tips can be made from plastic which is molded using any conventional technique, such as injection molded plastic or structural foamed plastic. Alternately, the replaceable fan blade tips can be machined from solid plastic. Where the replaceable fan blade tips are made from metal, they can be machined from solid stock, formed and welded from individual pieces, cast (or molded), or formed using any other conventional techniques. As mentioned previously, any composite material, including for example, carbon fiber, can be used to form the replaceable fan blade tips as well. Those skilled in the art will appreciate that the foregoing materials and techniques are by way of example only, and that any known material processed in any known way can be used to form the replaceable fan blade tips. 
     FIGS. 2,  2   a  and  2   b  show an exemplary embodiment of a snap-on replaceable fan blade tip in greater detail. 
     In FIG. 2 the assembly of fan blade  14  and replaceable fan blade tip  18  is shown. The fan blade  14  has a recess  15  into which—during rotation in the direction of arrow  22  in FIG. 2 a  —a corresponding fan blade tip of the other fan dives—due to the intersecting of the envelope curves of said fans  11 ,  12  as shown in FIG.  1 . 
     An attaching device, represented as a mounting area  16 , is defined by a plane where both fan blade  14  and replaceable fan blade tip  18  contact each other. A clip  20 , as shown in FIG. 2 b , can be included on the replaceable tip  18  for engaging an aperture  17  (FIG. 2 b ) in the mounting area of fan blade  14 . 
     FIG. 2 a  shows an exemplary embodiment of fan blade  14  having an aperture  17  with rectangular shape. FIG. 2 b  shows an exemplary embodiment of a corresponding fan blade tip  14  having an engaging clip  20  and an aligning pin  19 . The aligning pin engages a bore in the mounting area of fan blade  14  to align (for example, center) the fan blade tip with the fan blade. A product containing surface  21  of said fan blade tip  18  rotates into the direction of arrow  22  when mounted on fan blade  14  (FIG. 2 a ). 
     FIGS. 3,  3   a  and  3   b  show other exemplary embodiments of the present invention. In FIG. 3, a fan blade tip  14  has a receptacle, such as a threaded receptacle  23 , above the mounting area  16 . The receptacle can, for example, be an ultrasonic insert which is vibrated into place using ultrasound, in known fashion. The ultrasonic insert provides metal threads for mounting purposes. 
     The corresponding fan blade tips  24  and  25  shown in FIGS. 3 a  and  3   b , respectively each have an aligning pin  19  for engaging said bore in the mounting area  16  of said fan blade  14 . The fan blade tip  24  can, for example, be made of foamed material, whereas the fan blade tip  25  of FIG. 3 b  can be injection-molded, having recesses  26  being separated by traverses  27  to enhance stiffness of the fan blade tip  25 . By means of any fastening device such as a screw  28  or the like, the fan blade tips  24  and  25  can be mounted on fan blade  14 . The screw  28  or the like engages the threaded receptacle  23  provided in the plastic material as an alternative to the snap-on device shown in FIGS. 2-2 b.    
     FIGS. 4,  4   a  and  4   b  show further exemplary embodiments of the invention. In FIG. 4 a fan blade  29  has an end region  30 . In said end region  30  there is provided a recess  31  and two abutting surfaces  36 ,  37 . The corresponding fan blade tips  32 ,  33  shown in FIGS. 4 a  and  4   b , respectively each have abutting surfaces  36 ,  37  as well. In this exemplary embodiment, the fan blade tip  32  of FIG. 4 a  fits to the fan blade  29  of FIG.  4 . The configuration of a cam  35  for engaging the recess  31  of the fan blade end  30  matches that of the recess, allowing for a match of said abutting surfaces  36 ,  37  of fan blade  29  and fan blade tip  32 . Thus, the fan blade  29  and fan blade tip  32  contact along a contacting plane  38  with abutting surfaces  36 ,  37 , thereby maintaining a final position of said fan blade tip  32  on said fan blade  29 . FIG. 4 b  shows an exemplary embodiment which can be used for a fan wheel rotating in a different direction. 
     Fan blade tips  32  and  33  each comprise a recess  34  similar to recess  15  shown in FIGS. 1 and 2. The fan blade tips shown in the accompanying drawings can be made of any material. Further, by mounting fan blade tips formed of different materials, a balancing of the fan wheels  11 ,  12  can be achieved. In addition, any selected material, such as a light-weight plastic, can be reinforced with plated or coated reinforcing material. Furthermore, the shape of said cams  35  engaging a corresponding recess  31  is not limited to the shape of cam  35  shown in the drawings, but can be of any desired shape including rectangular, circular, square and so forth. Further, each cam  35  can be formed as a plurality of smaller cams. The recess  31  can, of course, be provided in the corresponding fan blade tips  32  and  33 , respectively, with the cam  35  being provided on the corresponding fan blade end  30 , in the mounting area. 
     FIGS. 4 a  and  4   b  represent that opposite hand tips can be provided for a blade in accordance with the present invention. Either tip can be mounted to the fan blade. The result is that opposite hand fans can be made from single fan bodies simply by mounting the desired hand tip. 
     It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential character thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes which come within the meaning and range of equivalents thereof are intended to be embraced therein.