Abstract:
The present invention relates to an improved taping apparatus which comprises a cam mechanism and a belt member disposed around the circumferential surface of the cam mechanism, whereby the belt member rotating along the periphery of the cam mechanism can continuously apply a tape around a peripheral surface of the object, in particular in the shape of a closed-loop, while the object is disposed within the central space of the cam mechanism, so that the tape can be automatically applied around the object and the productivity can be improved. The taping apparatus is characterized by an annular cam mechanism supported at both sides by frames and having an entrance formed through a part of the cam mechanism, through which entrance the object to be taped can be introduced into the central space of the cam mechanism; an annular belt member loosely encompassing the peripheral surface of the cam mechanism and extended across the entrance, so that when the object is introduced into the central space of the cam mechanism through the entrance, the belt member can be stretched and bring the tape into tight contact with the surface of the object; and a drive unit for rotating the cam mechanism so that the belt member can continuously contact the peripheral surface of the object and simultaneously apply the tape around the object.

Description:
This is a divisional of copending application Ser. No. 08/938,217 filed on Sep. 26, 1997, now U.S. Pat. No. 5,954,919, claims the benefit thereof and incorporates the same by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to taping apparatus, in particular to taping apparatus which can apply an adhesive tape around a closed-loop shaped object (e.g. a neck band formed within a horizontal deflection coil of a deflection yoke) in a continuous operation. 
     2. Description of the Prior Art 
     In general, apparatus for taping an adhesive tape around an object typically has a construction as shown in FIG.  1 . When a tape  6  is unwound and lowered an a predetermined distance from the tape reel  4 , and then moved toward the object by a moving member  5   a,  horizontal and vertical moving rollers  1   a  and  1   b  which are respectively displaced by a horizontally movable cylinder  1  and a vertically movable cylinder  2  will apply the tape around the peripheral surface of the object  3 . With the conventional taping apparatus constructed in this manner, a length of the tape  6  moved toward the object  3  is cut by a tape cutter  7  and then adhered on the peripheral surface of the object  3  by the horizontally and vertically moving rollers  1   a  and  2   b,  which are moved forward and backward by the cylinders  1  and  2 , respectively. 
     However, the taping apparatus of the above type has disadvantages in that its taping operation should be precisely conducted since the tape  6  is applied while the two cylinders  1  and  2 , which are independent from each other, perform linear displacements in a connective manner, and in that the time needed for the taping operation is very long since those cylinders move alternately and sequentially. Furthermore, the winding turns of the tape are relatively limited since the tape may deviate from the determined running path during the taping operation and the apparatus lacks compatibility since the mechanical conditions have to be changed whenever the types and sizes of objects to be taped are varied. 
     SUMMARY OF THE INVENTION 
     The present invention is conceived to solve the problems of the prior art and the purpose of the present invention is to provide an improved taping apparatus which comprises a cam mechanism and a belt member disposed around the circumferential surface of the cam mechanism, whereby the belt member rotating along the periphery of the cam mechanism can continuously apply a tape around a peripheral surface of the object, in particular in the shape of a closed-loop, while the object is disposed within the central space of the cam mechanism, so that the tape can be automatically applied around the object and the productivity can be improved. 
     In order to achieve the above purpose, the present invention provides taping apparatus characterized in that it comprise an annular cam mechanism supported at both sides by frames and having an entrance formed through a part of the cam mechanism, through which entrance the object to be taped can be introduced into the central space of the cam mechanism; an annular belt member loosely encompassing the peripheral surface of the cam mechanism and extended across the entrance, so that when the object is introduced into the central space of the cam mechanism through the entrance, the belt member can be stretched and bring the tape into tight contact with the surface of the object; and means for rotating the cam mechanism so that the belt member can continuously contact the peripheral surface of the object and simultaneously apply the tape around the object. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 a  to  1   f  are simplified views diagrammatically showing the operating conditions of a conventional taping apparatus in sequence; 
     FIG. 2 is an exploded perspective view of the taping apparatus of the present invention; 
     FIG. 3 is a cross-sectional plan view of the taping apparatus of the present invention; 
     FIGS. 4 a  to  4   d  are front views diagrammatically showing the operating conditions of the taping apparatus of the present invention in sequence; 
     FIG. 5 is a cross-sectional view showing a driving roller and a driven roller of the taping apparatus of the present invention; 
     FIG. 6 is a front view showing in cross-section positioning rollers of the taping apparatus of the present invention; 
     FIG. 7 is a cross-sectional view taken along the line A—A of FIG. 6; 
     FIG. 8 is a perspective view showing the taping apparatus, into which an object is introduced; and 
     FIG. 9 is a perspective view showing the taping apparatus with the door thereof being closed. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2 is an exploded perspective view of the taping apparatus of the present invention and FIG. 3 is a cross-sectional plan view thereof. The taping apparatus comprises an annular cam mechanism  10  for surrounding the peripheral surface of an object  27  to be taped, means  15  for rotating the cam mechanism  10 , and a belt member  14  fitted around the circumferential surface of the cam mechanism  10  in such a manner that it can be rotated together with the cam mechanism  10  and simultaneously compress the tape to be applied against the peripheral surface of the object  27 . The cam mechanism  10  is formed by bending a band plate with a constant width in an annular shape, and providing an entrance  11  through a portion thereof. Furthermore, the cam mechanism  10  is provided with flanges  12  with a constant height around front and rear sides thereof so as to prevent the belt member  14  from being taken off from the circumferential surface of the cam mechanism  10 . 
     The entrance  11  is used as a passage for introducing a closed-loop shaped object  27  (e.g. a neck band which formed on the rear end of a horizontal deflection coil of a deflection yoke) into the central space of the cam mechanism  10 , and the taping operation of tape  29  starts when the object  27  is positioned within the central space of the cam mechanism  10 . A plurality of rotating guide pins  13  are horizontally extended between the flanges  12  and the belt member  14  is fitted over the guide pins  13 . Therefore, a gap is present between the belt member  14  and the circumferential surface of the cam mechanism  10 . Furthermore, the belt member  14  extends across the entrance  11  and in this position, the belt member is exposed to a part of the peripheral surface of the object  27  which is ready to be taped. The belt member  14  is formed from a rubber material having such a sufficient flexibility that it can be elongated when the object  27  is moved into the central space of the cam mechanism  10 . 
     The rotating means  15  includes a pair of frames  16  for rotatively supporting the cam mechanism  10 . These frames  16  are arranged at rear and front sides of the cam mechanism  10 , respectively, and each frame  16  is provided with a hole  16   a,  the center of which coincides with that of the cam mechanism  10 . 
     Preferably, the holes  16   a  have a dimension substantially the same as that of the internal circumferential surface of the cam mechanism  10 , and each frame  16  is also provided with an entrance  16   b  corresponding to the entrance  11  formed in the cam mechanism  10 , the entrance  16   b  communicating with the hole  16 . Therefore, the object  27  does not interfere with any of the entrances  11  and  16   b  when it is moved into the central space of the cam mechanism  10 . Furthermore, a circular rail  21  is formed on each of the internally opposing surfaces of the frames  16  along the periphery of the corresponding hole  16   a  to encircle one flange  12  of the cam mechanism  10 . The flanges  12  are provided with a plurality of rolling members  20  around their outer surfaces, by which members the rotation of the cam mechanism  10  is smoothly guided between the frames  16 . Furthermore, a number of external gear teeth are formed around the external circumferential surface of each flange  12 , and a driving gear  18  meshing with the external gear teeth is provided to be rotatable between the frames  16 . 
     The driving gear  18  is rotated by a motor  19  mounted on the outer surface of each frame  16 , and a door  22  is mounted on a side of the entrance  11  formed in the cam mechanism  10 . The door  22  is rotated about a hinge pin  24  by its weight and closes the entrance  11 . The outer circumferential surface of the door  22  has a curvature substantially the same as that of the outer circumferential surface of the cam mechanism  10 , and a number of teeth meshing with the driving gear  23  is formed on the outer circumferential surface of the door  22 . Furthermore, within the inside of frames  16 , there are provided stop pins  26  just below the hinge pin  24  of the door  22 . Therefore, while the cam mechanism  10  is rotating, the door  22  can be pivoted about the hinge pin  24  under the condition that the external circumferential surface thereof abuts against the stop pins  26 , whereby the entrance  11  can be automatically closed. And, a bearing member  25  is provided in the inside of the door  22 , and when the door  22  is closed, the bearing member  28  pushes the tape  22  into tight contact with the surface of the belt member  14 , so that there will be no gap created between the belt member  14  and the tape  29 . 
     FIG. 4 a  is a schematic front view of the taping apparatus of the present invention. The tape  29  is unwound from a tape reel  22 , moved through a driving roller  30 , a driven roller  33  and positioning rollers  34 , and then positioned parallel to the part of the belt member  14  facing toward the entrance  11 . Then, if the object  27  is moved into the central space of the cam mechanism  10 , the belt member  14  is stretched due to its flexibility and the tape  29  is tightly contacted to the external surface of the object  27 . Thereafter, the tape  29  is cut to a desired length by a cutter  38  and then the belt member  14  makes the tape continuously contact with the external surface of the object  27  while the cam mechanism  10  rotates, in the course of which the cut tape  29  is compressed between the belt and the object, and wrapped around the peripheral surface of the object  27 . 
     FIG. 5 is a partial section view showing the driving roller and the driven roller of the present invention. The driving roller  30  located at the left side of the tape reel  28  around which the tape  29  is wound is rotated by a driving means which is not shown. The driving roller  30  is coated with an adhesion-resistant film  31  along the periphery thereof, around a part of which the adhesive surface of the tape  29  is wrapped, and the tape is fed toward its unwinding direction while the driving roller  30  is rotating. Along a circumferential portion of the adhesion-resistant film  31  contacted with the tape, a frictional force is generated due to the close contact between the adhesion-resistant film  31  and the tape adhesive. However, either the tape winding portion or unwinding portion of the tape comes into or goes out of the end portions of the contacted part in the tangentially extended states and thus no frictional force is generated between the adhesion-resistant film and the tape any further. In other words, the part of the tape  29  which is circumferentially contacted with a part of the adhesion-resistant film  31  will be frictionally accompanied with the circumferentially contacted portion since the tape  29  is circumferentially extended and wrapped around that portion, whist at the opposite end portions of the contacted part, the tape will be separated from the surface of the adhesion-resistant film  31  since at those end portions the tape straightly extends in the tangential directions. Therefore, the tape  20  will be unwound from the tape reel and transferred in the desired direction by the frictional force generated between the surface of the adhesion-resistant film and the adhesive surface of the tape while the driving roller  30  is rotating. A guide roller is also provided for supporting the tape between the driving roller  30  and tape reel  28 , so that the tape can be wrapped around the adhesion-resistant material  30  as wide as possible. 
     The driven roller  33  is located at the left upper side of the driving roller  32 , so that the tape  20  can be sufficiently contacted to the adhesion-resistant film  31 , thus generating a frictional force sufficient to move the tape. The driven roller  33  is also coated with a adhesive-resistant film. Therefore, when the adhesive surface  29   a  of the tape is contacted to the circumferential surface of the driven roller  33 , a frictional force is also generated along the circumferential surface of the driven roller  33 , whist at the opposite end portions of the contacted tape portion, no frictional force is generated since the tape is tangentially extended at those end portions and separated from the surface of the adhesive-resistant film coated along the periphery of the driven roller  33 . 
     If the tape  29  has adhesive materials on its both sides, the adhesive material of one side will contact to the adhesion-resistant film  31  of the driving roller and the other side will contact to the adhesion-resistant film of the driven roller  33 . In this process, the tape will frictionally accompanied with the driven roller  33 , since the tape circumferentially wraps so sufficiently wide a portion of the adhesion-resistant film as to produce a frictional force. However, since the winding portion coming into the contacted portion and the unwinding portion going out of the contacted portion of the tape are tangentially extended from the ends of the contacted portion, the tape will separate from the surface of the adhesion-resistant film of the driven roller  33 . 
     FIG. 6 is a front view of the positioning rollers in cross-section and FIG. 7 is a sectional view taken along the line A—A of FIG. 6. A pair of positioning rollers  34  are provided just below the driven roller  33  for constantly retaining the running position of the tape  29 . The positioning rollers  34  serve to guide the tape portion disposed between a part of the belt member  14  facing the entrance  11 , and the object  27  to be taped. These positioning rollers  34  are alternately disposed in upper and lower positions, thus inhibiting tape shaking. A pair of flanges  35  are extended along the periphery of each positioning roller  34  for constantly retaining left and right longitudinal edges of the running tape  29 , and thus the flanges  35  and each circumferential surface of the positioning rollers  34  form a running path of the tape  39 . Furthermore, adhesion-resistant films  36  are coated on the circumference surfaces of positioning rollers  34  and on the corresponding surfaces of the flanges  35 , so that the adhesive surface  29   a  of the tape will not interfere with the positioning rollers  34  and the flanges  35 . Reference numeral  38  indicates a cutter for cutting the tape  29  to a predetermined length. 
     In the taping apparatus in accordance with the present invention constructed as explained herein-above, the door  22  pivots about the hinge pin  24  by its weight at the initial state, in which state the entrance  11  faces the object  27  to be taped, as shown in FIG. 4 a , and thus the entrance  11  is opened. Furthermore, if the driving roller  30  rotates, the tape  29  is unwound from the tape reel  29  and runs through the positioning rollers  34 . And then the tail of the tape  29  is further moved to the entrance  11 , and the tape  20  is located parallel to the one side of the belt member  14  extended over the entrance  11 . 
     As explained above, the tape  29  is moved by the frictional force generated between the tape and the adhesion-resistant film  31 . Therefore, while the driving roller  30  is rotating, the tape is continuously moved by the frictional force. And, at each end of the contacted portion, the tape is always separated from the surface of the adhesion-resistance film  31 , since the tape is either tangentially wound on or unwound from those end portions. The adhesion-resistant film  31  is formed from a material which does not adhere to the adhesive surface  29   a  of the tape, and thus the tape  29  can be easily released from the circumferential surface of the adhesion-resistant film  31  since no frictional force is generated when the tape  29  is tangentially wound on or unwound from the driving roller  30 . Therefore, even through the tape  29  is circumferentially contacted on the surface of the driving roller  30 , thus generating a frictional force, the tape is not permanently adhered to the surface of the driving roller  30  and can be easily released from the circumferential surface of the adhesion-resistant film when it is wound on or unwound from the driving roller, whereby the tape  29  can be continuously supplied. The tape portion unwound from the driving roller  30  will partially wrap around the circumferential surface of the driven roller  33  and can be continuously moved in the same manner as on the drawing roller  30 . Finally, the tape  29  is supplied to the cam mechanism  10  through the positioning rollers  34 . Thereafter, when the object  27  is moved toward the entrance  11  by a moving means such as a jig means, as shown in FIGS. 4 a ,  4   b  and  8 , the tape  29  and the belt member  14  are pushed backward and the tape  29  is closely contacted to the periphery of the object by the tensioned belt member  14 . Furthermore, when the object  27  is located at the central space of the cam mechanism  10 , the movement of the tape is stopped. Simultaneously, the stopped tape  29  is cut to a predetermined length and then the taping operation of the tape  29  starts again. 
     As the taping operation starts, the rotation of the motor  19  makes the driving gear  18  rotate. If so, the cam mechanism  10  connected to the driving gear  18  though the externally toothed gears  17  rotates counter-clockwise as shown in FIGS. 4 e,    4   d  and  9 . The cam mechanism  10  smoothly rotates since a number of wheels  20  distributed along the outer opposite surfaces of frames  12  ride on the rails  21 , and then the door  22  is pivoted about the hinge pin  24  by the stop pin  26  engaged with the door while the cam mechanism  10  rotates, thus closing the entrance  11 . Then, the supporting member  25  provided inside the door  22  contacts the tape  29  and prevents the tape from leaving its path while taping is performed. While the cam mechanism  10  rotates, the belt member  14  is continuously contacted around the peripheral surface of the object and thus the tape  29  is applied around the peripheral surface in the compressed state. If the taping operation is completed, the rotation of the cam mechanism  10  is stopped and the door  22  faces the entrance  16   b  formed through the frames  16 . When the cam mechanism  10  is stopped, entrances  11  and  16   b  are correspondingly located as shown in FIG. 4 a  and then the object  27  is pushed backward by a separate jig means. When the object  27  is pushed backward, the door is contacted by the object  27  and cooperates therewith. Then, the door  22  pivots about the hinge pin  24  by its weight and the entrances are opened, and during this process the object  27  is discharged. 
     As explained above, the tape applying apparatus in accordance with the present invention is provided with annular cam mechanism formed with an entrance radially through a part thereof and a flexible belt member located around the circumferential surface of the cam mechanism. Since the belt member is exposed through the entrance, the belt member is stretched and contacted by a loop-shaped object in the tensioned state as the object is introduced into the cam mechanism, whereby the tape portion sandwiched between the object and the belt member will be adhered to the peripheral surface of the object. Thereafter, while the cam mechanism is rotating in a direction by a rotating means, the belt member will be continuously contacted with the peripheral surface of the object and thus the tape can be applied around the object. Therefore, according to the present invention, a tape can be continuously applied around the peripheral surface of an object even though the object has a closed-loop shape, and thus the taping operation can be automatized.