Patent Publication Number: US-2007102120-A1

Title: Sheet member transfer device

Description:
TECHNICAL FIELD  
      The present invention relates to a sheet member transfer device for transferring a sheet member from a transfer drum to a receiving drum.  
     RELATED ART  
      A conventional sheet member transfer device is disclosed, for example, in Patent Document 1 which is identified below. 
      Patent Document 1: JP-2001-315219A    

      This known sheet member transfer device includes a transfer drum having an outer peripheral surface for bearing a sheet member thereon, and a tire-building drum onto which the sheet member is transferred from the transfer drum with the tire-building drum urged against the transfer drum and rotated in opposite direction with reference to the transfer drum. In this instance, the transfer drum is formed with a hollow chamber that is connected to a suction device, and a plurality of suction holes in its outer peripheral surface, which are in communication with the hollows chamber.  
      With this type of sheet member transfer device, while applying a suction force of the suction device to the hollow chamber, a sheet member is fed to the transfer drum and attracted to the suction holes so as to be applied to the transfer drum. Subsequently, the transfer drum is urged against the tire-building drum and the operation of the suction device is stopped. The transfer drum and the tire-building drum are then rotated in the opposite directions in order to transfer the sheet member from the transfer drum to the tire-building drum.  
     DISCLOSURE OF THE INVENTION  
      (Task of the Invention)  
      However, with such an arrangement of the conventional sheet member transfer device, since the sheet member is held on the transfer drum by an attraction force generated by vacuum, there has been such a problem that the sheet member is sucked into the suction holes thereby causing a number of suction traces over a wide surface region of the sheet member. Moreover, in order to positively hold the sheet member on the transfer drum, it is necessary to ensure that the surface area in which the suction holes are arranged is smaller than the sheet member in order to avoid suction of ambient air from the suction holes while the sheet member is being held. However, such an arrangement would not allow the sheet member to be sucked along the outer edges (inclusive of the leading end), giving rise to a further problem that the outer edge portion of the sheet member, which is being held on the transfer drum, is separated from the transfer drum and thereby deformed.  
      It is therefore an object of the present invention to provide an improved sheet member transfer device, which allows the transfer of the sheet member to be performed easily and positively, while preventing its deformation.  
      (Solution of the Task)  
      (1) The present invention in its first aspect resides in a sheet member transfer device for forming a cylindrical tire constitutive member by joining a leading end and a trailing end of a sheet member with each other, wherein the sheet member is formed by successively joining side edges of a plurality of narrow strip members with each other, said strip members having a constant width, said sheet member transfer device comprising: 
      a transfer drum for forming the sheet member by applying said plurality of strip members onto an outer peripheral surface of the transfer drum so that the width direction of each strip member is oriented in the circumferential direction of the transfer drum, and a receiver drum for forming the cylindrical tire constitutive member by joining the leading end and the trailing end of the sheet member which has been transferred from the transfer drum, with said transfer drum urged against the receiver drum and said receiver drum rotated in an opposite direction to the transfer drum;     said transfer drum being provided, on its outer peripheral surface, with a leading end application region for applying a strip member forming said leading end of the sheet member, and a plurality of application regions following said leading end application region and arranged in the circumferential direction of the transfer drum at a pitch which corresponds to the width of the strip member, said application regions being divided into a plurality of low adhesion sections with a low adhesion force, and a plurality of high adhesion sections with a high adhesion force, said low adhesion sections and said high adhesion sections being alternately arranged in the width direction of the transfer drum;     radial expansion/contraction means for moving the high adhesion sections radially inwards of the low adhesion sections, said high adhesion sections and low adhesion sections being flush with each other when the narrow strip members are applied to the transfer drum, and said high adhesion sections being moved by said radial expansion/contraction means radially inwards of the low adhesion sections, when the sheet member is transferred from the transfer drum to the receiver drum;     said radial expansion/contraction means comprising collective expansion/contraction means for moving radially inwards the high adhesion sections in the leading end application region and the application region adjacent thereto, respectively, and moving means for individually moving radially inwards the high adhesion sections in the remaining application regions;     said collective expansion/contraction means comprising cam followers which are connected to the high adhesion sections, respectively, and movable radially inwards and outwards, a rotary cam which can be rotated to move the cam followers radially inwards and outwards, and cam driving means for rotating the rotary cam in the circumferential direction of the transfer drum.    

      The present invention in its second aspect resides in a sheet member transfer device according to the first aspect, wherein the low adhesion sections in at least the leading end application region are comprised of resilient material.  
      The present invention in its third aspect resides in a sheet member transfer device according to the first or second aspect, wherein the low adhesion sections in at least the leading end application region are comprised of silicone rubber at least in outer surface regions thereof.  
      The present invention in its fourth aspect resides in a sheet member transfer device according to any one of the first to the third aspects, wherein the high adhesion sections in at least the leading end application region have outer surfaces in the form of mirror-finished surfaces.  
      The present invention in its fifth aspect resides in a sheet member transfer device according to the fourth aspect, wherein the mirror-finished surfaces are formed by plating with respect to the outer surfaces.  
      The present invention in its sixth aspect resides in a sheet member transfer device according to any one of the first to the fifth aspects, wherein the low adhesion sections and the high adhesion sections in at least the leading end application region are arranged alternately in the axial direction.  
      (Effects of the Invention)  
      According to the first aspect of the present invention, upon application of the narrow strip members to the transfer drum, when the high adhesion sections are moved by the moving means to be flush with the low adhesion sections, the narrow strip members are supplied to, and urged against the corresponding adhesion sections of the transfer drum so that the narrow strip members are tightly adhered, in particular, to the high adhesion sections. Here, the high adhesion sections and the low adhesion sections are not limited to an arrangement they are smaller in surface area than the narrow strip members as in the conventional suction holes. Thus, the high adhesion sections and the low adhesion sections can be made larger in surface area than the narrow strip members so as to ensure that the narrow strip members are positively held in place, over their entire regions, particularly by the adhesion force of the high adhesion sections.  
      Furthermore, when the sheet member is to be transferred from the transfer drum and applied to the receiver drum, first of all, the high adhesion sections are moved by the radial expansion/contraction means radially inwards of the low adhesion sections so that the sheet member is held solely by the low adhesion sections. In such a condition, with the transfer drum urged against the receiver drum, the transfer drum and the receiver drum are rotated in the opposite directions so as to transfer the sheet member from the transfer drum to the receiver drum. In this instance, since the sheet member is held solely by the low adhesion sections, the sheet member can be readily separated from the transfer drum and positively transferred onto the receiver drum. Here, while being held on the transfer drum, the sheet member is adhesively held in place particular by the high adhesion sections so as to prevent formation of suction traces over a wide surface region, as would be unavoidable in the prior art.  
      Moreover, according to the present invention, the radial expansion/contraction means is comprised of collective expansion/contraction means for moving radially inwards the high adhesion sections in the leading end application region and the application region adjacent thereto, respectively, and moving means for individually moving radially inwards the high adhesion sections in the remaining application regions, and the collective expansion/contraction means includes cam followers which are pivoted to the high adhesion sections, respectively, and movable radially inwards and outwards, a rotary cam which can be rotated to move the cam followers radially inwards and outwards, and cam driving means for causing the rotary cam to be rotated in the circumferential direction of the transfer drum. Therefore, the transfer device can be simplified in structure, as compared to an arrangement wherein the high adhesion sections in all the application regions are individually moved radially inwards by such moving means as cylinder devices.  
      According to the second aspect of the present invention, even when the distance between the transfer drum and the receiver drum is not larger than zero, the sheet member can be transferred onto the receiver drum under a resilient deformation of the low adhesion sections, thereby facilitating the adjustment of the distance between these drums.  
      The third and the fourth aspects of the present invention both allow the low adhesion sections to be formed easily and at low cost.  
      The fifth aspect of the present invention similarly allows the high adhesion sections to be formed easily and at low cost.  
      The sixth aspect of the present invention makes it readily possible to realize a narrow pitch of the high and the low adhesion sections. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a partially broken side view showing a first embodiment of the present invention;  
       FIG. 2  is a side view showing the leading end application region of the transfer drum;  
       FIG. 3  is a sectional view taken along the line I-I in  FIG. 2 ;  
       FIG. 4  is a sectional view taken along the line II-II in  FIG. 2 ; and  
       FIG. 5  is a side view showing a second embodiment of the present invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      First of all, the basic concept of the present invention will be explained below with reference to the drawings.  FIGS. 1 through 4  illustrate a sheet member transfer device representing the basic concept of the present invention, wherein reference numeral  11  denotes a cylindrical transfer drum which is rotatable about a horizontal axis. The transfer drum  11  has an outer peripheral surface which is applied with a sheet member  12  to be transferred to a receiver drum explained hereinafter, which may be a tire building drum, for example. The sheet member h 12  as a length which is substantially the same as the peripheral length of the transfer drum  11 . Here, such a sheet member  12  is formed by repeating the steps of applying a narrow strip member  13  having a small width and a predetermined length, to the outer peripheral surface of the transfer drum  11  so as to extend in the width direction thereof, rotating the transfer drum  11  by an amount which corresponds to the width of the narrow strip member  13 , and then applying a subsequent narrow strip member  13  to the outer peripheral surface of the transfer drum  11  so as to extend in the width direction thereof, with its side edge in tight contact with the corresponding side edge of the previous narrow strip member  13 .  
      Such application of the narrow strip members  13  is performed multiple times, the number of which corresponds to that for the nominal rim diameter of the pneumatic tire to be produced, e.g., 17 times when the nominal rim diameter is 17 inches. In this way, when the sheet member  12  has been formed on the peripheral surface of the transfer drum  11 , the transfer drum  11  is moved in a translation manner toward the receiver drum and then urged against the receiver drum and rotated so as to transfer the sheet member  12  from the transfer drum  11  to the receiver drum. On the receiver drum, the leading end and the trailing end of the sheet member  12  is joined to each other so that the sheet member  12  now assumes a cylindrical shape.  
      When the sheet member  12  is made of a plurality of narrow strip members  13 , the number of which corresponds to the number of the nominal rim diameter, it is possible readily to prepare different pneumatic tires corresponding to different rim diameters, e.g., 15 inches to 20 inches, by using the same transfer drum  11  and transferring different sheet members  12  to receiver drums of different diameters. Here, the sheet member  12  may be an inner liner consisting of unvulcanized rubber, a carcass ply consisting of unvulcanized rubber and reinforcement cords embedded therein, etc.  
      The transfer drum  11  comprises a main shaft  15  arranged on a rotational axis, support discs  16  fixedly secured to a proximal end and a distal end of the main shaft  15  coaxially thereto, and an outer cylinder  17  having an inner periphery that is fixedly secured to the radially outer edges of the support discs  16 , coaxially to the main shaft  15 . The outer cylinder  17  has an open slit  18  which is formed at a single peripheral location, to extend from one end to the other end of the outer cylinder in the axial direction. The location of the slit  18  is the location where the narrow strip member  13  forming the leading end of the sheet member  12  is applied.  
      Reference numeral  21  denotes support blocks fixedly secured the radially outer edges of the support discs  16 , respectively. Each support block  21  is accommodated in the slit  18  so as to cover the slit  18 , and has an outer periphery formed with a recess  22  of substantially rectangular cross-section, which extends in the axial direction. Reference numeral  23  denotes interpolating bars arranged in the recess  22 , each having both ends fixedly secured to the walls of the recess  22  so that the interpolating bar  23  is supported by the support block  21  to extend in the axial direction. The interpolating bar  23  has an outer edge of arcuate shape, which is flush with the outer periphery of the outer cylinder  17 . The interpolating bar  23  fills the slit  18  in the outer cylinder  17  so that the outer periphery of the outer cylinder  17  is continuously cylindrical.  
      The interpolating bars  23  are each made of a resilient material which exhibit a low adhesion to unvulcanized rubber and which can be readily deformed elastically; to be more specific, they are made of silicone rubber. When the interpolating bar  23  exhibits low adhesion, the sheet member  12  in tight contact with the interpolating bar  23  can be readily separated and removed from the interpolating bar  23 . A plurality of through holes  26  of rectangular cross-section are formed at the middle portion of the interpolating bar  23 , as seen in the circumferential direction, so as to extend in the radial direction. These through holes  26  are aligned in the axial direction and spaced from each other by a constant distance.  
      Support bars  29  are arranged on the radially inner side of the interpolating bars  23 , to extend in parallel therewith. Each support bar  29  has both ends extending through radial slits  30  which are formed in the support discs  16 . Reference numeral  31  denotes a plurality of retainer plates, the number of which corresponds to the number of the through holes  26 . Each retainer plate  31  has a radially outer end portion that is inserted into the associated through hole  26 , and a radially outer surface which is flush with the outer peripheral surface of the outer cylinder  17  and the interpolating bars  23 , when the support bar  29  has been moved to its radially outermost position. The radially outer surface of the retainer plate  31  is retracted radially inwards from the interpolating bars  23  while being guided by a guide member, when the support bar  29  is moved radially inwards.  
      Furthermore, the radially outer surface of the retainer plate  31  is in the form of a mirror-finished surface formed by plating, such as nickel plating, chromium plating, or the like. As a result, when the sheet member  12  is urged against the radially outer surfaces of the retainer plates  31 , the sheet member  12  is brought into tight adhesion with the retainer plates  31  by intensive adhesion force. Here, when the narrow strip members  13  constituting the sheet member  12  are applied to the transfer drum  11 , the leading end of the sheet member  12  or the leading end of the first narrow strip member  13  is supplied to an area between one circumferential end  31   a  and the other circumferential end  31   b  of the retainer plate  31 . Thus, the area between one circumferential end  31   a  and the other circumferential end  31   b  of the retainer plate  31  constitutes the leading end application region  33  of the transfer drum  11 , to which the leading end of the sheet member  12  is applied.  
      The leading end application region  31  is divided into a plurality of low adhesion sections in the form of the interpolating bars  23 , and a plurality of high adhesion sections in the form of the retainer plates  31 . The low adhesion sections comprising the interpolating bars  23 , which are situated between the retainer plates  31  in the leading end application region  33 , exhibit a low adhesion force with respect to the sheet member  12  so that the sheet member  12  can be readily separated and removed. The high adhesion sections comprising the retainer plates  31  are arranged in the axial direction alternately with the interpolating bars  23  forming the low adhesion sections, and exhibit strong adhesion force with respect to the sheet member  12 .  
      When the interpolating bars  23  (the low adhesion sections) and the retainer plates  31  (the high adhesion sections) are axially arranged alternately with each other in the leading end application region  33 , it is readily possible to minimize the pitch of the interpolating bars  23  and the retainer plates  31  to thereby ensure that the leading end of the sheet member  12  is adhesively retained in a positive manner. When the interpolating bars  23  (the low adhesion sections) are made of resilient material, as mentioned above, even if the distance between the transfer drum  11  and the receiver drum is not larger than zero, the sheet member  12  can be transferred onto the receiver drum under a resilient deformation of the interpolating bars  23 , thereby facilitating the adjustment of the distance between these drums.  
      Also, when the low adhesion sections (the interpolating bars  23 ) is entirely made of silicone rubber, it is possible to form the low adhesion sections easily and at low cost. Here, when at least the outer surface portions of the low adhesion sections are made of silicone rubber, the separation and removal of the sheet member  12  from the low adhesion sections (the interpolating bars  23 ) can be facilitated. Therefore, silicone rubber may be applied only with respect to the outer surface portions of the low adhesion sections. Furthermore, as mentioned above, the outer surfaces of the high adhesion sections, i.e., the radially outer surfaces of the retainer plates  31 , which are formed as mirror-finished surfaces by plating, can also be formed easily and at low cost.  
      Reference numeral  35  denotes cylinders secured to the support discs  16  to extend in the radial direction, each having a piston rod  36  with a tip end which is connected, via an intermediate member  37 , to the relevant axial end of the support bar  29 . When the cylinder  35  is operated and the piston rod  36  is extended to its stroke end, the retainer plate  31  is moved radially outwards such that the radially outer surface of the retainer plate  31  is flush with the outer surfaces of the interpolating bars  23  and the transfer drum  11 . On the other hand, when the piston rod  36  is retracted to its stroke end, the radially outer surface of the retainer plate  31  is retracted radially inwards from the outer surfaces of the interpolating bars  23  and the transfer drum  11 . The above-mentioned cylinders  35  and the intermediate members  37  as a whole constitute the moving means  38  for moving the high adhesion sections in the form of the retainer plates  31  radially inwards from the low adhesion sections in the form of the interpolating bars  23 .  
      Reference numeral  41  denotes a plurality of through hole groups spaced from each other in the circumferential direction by a constant distance, which is substantially the same as the width of the narrow strip member  13 . Each though hole group  41  is comprised of a plurality of radially extending through holes  42  with a rectangular cross-section, which are spaced from each other in the axial direction by a constant distance. Reference numeral  43  denotes a plurality of retainer bars each extending in the axial direction with both ends extended through respective slits  40  formed in the support discs  16 . The number of the retainer bars  43  is the same as the number of the through hole groups  41 . These retainer bars  43  are spaced from each other (and from the through hole groups  41 ) by a constant distance in the circumferential direction. Each retainer bar  43  is comprised of a main body portion  43   a  in the form of rectangular column, as well as a plurality of projections  43   b  projecting radially outwards from the outer surface of the main body portion  43   a . The number of the projections  43   b  is the same as the number of the through holes  42 . There projections  43   b  are spaced from each other by a constant distance in the axial direction, similarly to the through holes  42 , and have a cross-section which corresponds to that of the through holes  42 .  
      The retainer bars  43  are associated with the respective through hole groups  41  such that the projections  43   b  are inserted into the through holes  42  from radially inner side. Here, when the retainer bars  43  have been moved to their radially outermost positions, the radially outer surfaces of the projections  43   b  are flush with the outer periphery of the outer cylinder  17 . On the other hand, when the retainer bars  43  are moved radially inwards, the radially outer surfaces of the projections  43   b  are retracted radially inwards from the outer periphery of the outer cylinder  17  while being guided by guide members  44 .  
      Similarly to the retainer plate  31 , the radially outer surface of each projection  43   b  is in the form of a mirror-finished surface formed by plating. As a result, when the sheet member  12  is urged against the radially outer surfaces of the projections  43   b , the sheet member  12  is brought into tight adhesion with the retainer bars  43  by intensive adhesion force. On the other hand, the outer peripheral surface of the outer cylinder  17  is coated by a coating layer comprised of low adhesion material, i.e., silicone rubber in the illustrated embodiment, so that the sheet member  12  can be readily separated and removed from the outer cylinder  17 .  
      In this way, beginning from the leading end application region  33  to be applied with the narrow strip member  13  forming the leading end of the sheet member  12 , a plurality of application regions to be applied with the respective narrow strip members are arranged on the outer peripheral surface of the transfer drum  11  at a constant pitch in the circumferential direction, which corresponds to the width of the narrow strip members  13 . These application regions are divided into high adhesion sections, i.e., those sections which can be moved integrally with the retainer bars  43 , and low adhesion sections, i.e., those sections of the outer cylinder  17 , which are situated between the retainer bars  43 , wherein the high adhesion sections and the low adhesion sections are alternately arranged in the circumferential direction. In the transfer drum  11  excluding the leading end application region  33 , the alternate arrangement of the retainer bars  43  (high adhesion sections) and the surface regions of the outer cylinder  17  between the retainer bars  43  which are adjacent to each other in the circumferential direction (low adhesion sections) can be realized easily and at low cost.  
      Reference numeral  45  denotes a plurality of cylinders (corresponding in number to the retainer bars  43 ) secured to the support discs  16  to extend in the radial direction, each having a piston rod  46  with a tip end which is connected, via an intermediate member  47 , to the relevant axial end of the retainer bar  43 . When the cylinder  45  is operated and the piston rod  46  is extended to its stroke end, the retainer bar  43  is moved radially outwards such that the radially outer surface of the projection  43   b  in the retainer bar  43  is flush with the outer surfaces of the outer cylinder  17 . On the other hand, when the piston rod  46  is retracted to its stroke end, the radially outer surface of the projection  43   b  in the retainer bar  43  is retracted radially inwards from the outer surfaces of the outer cylinder  17 . The above-mentioned cylinders  45  and the intermediate members  47  as a whole constitute the moving means  48  for moving the high adhesion sections in the form of the retainer bars  43  radially inwards from the low adhesion sections in the form of the portions of the outer cylinder  17  between the retainer bars  43 .  
      Reference numeral  51  denotes a cylindrical receiver drum which is arranged on one side of the transfer drum  11  so as to be rotatable about a horizontal axis. As mentioned above, the sheet member  12  is transferred from the transfer drum  11  to the outer peripheral surface of the receiver drum  51 . On this occasion, the receiver drum  51  is urged by the transfer drum  11  and rotated in opposite direction to the transfer drum  11 .  
      The receiver drum  51  in its outer peripheral surface includes a leading end application region  52  to which the leading end of the sheet member  12  is applied. The leading end application region  52  is provided with a rubber band  53  having an outer surface in the form of a mirror-finished surface. Provision of the rubber band  53  having a mirror-finished outer surface at the leading end application region  52  of the receiver drum  51  ensures that the leading end of the sheet member  12  can be easily and positively transferred from the transfer drum  11  to the receiver drum  51 .  
      Reference numeral  54  denotes a vacuum member arranged on the radially inner side of the rubber band  53 . A vacuum chamber  55  is formed between the vacuum member  54  and the rubber band  53 , which is connected to a vacuum source, not shown. The rubber band  53  is formed with a plurality of vacuum passages extending therethrough and communicated with the vacuum chamber  55 . Such arrangement ensures that, upon transfer of the leading end of the sheet member  12  from the transfer drum  11  to the receiver drum  51 , the leading end of the sheet member  12  is sucked by vacuum through the vacuum passages  56  to positively transfer the leading end.  
      The operation of the transfer device according to the basic concept of the present invention will be described below. It is assumed that the transfer drum is waiting at the sheet member forming position. In this instance, the piston rods  36 ,  46  of the cylinders  35 ,  45  are extended to their stroke ends so that the high adhesion sections formed by the radially outer surfaces of the retainer plates  31  and the retainer bars  43  (projections  43   b ) are flush with the low adhesion sections formed by the outer surfaces of the interpolating bars  23  and the outer peripheral surfaces of the outer cylinder  17 .  
      When the first narrow strip member  13  forming the leading end of the sheet member  12  is supplied to the transfer drum  11  and urged against the leading end application region  33 , the narrow strip member  13  (the leading end of the sheet member  12 ) is intensively adhered to the high adhesion sections. Here, the high adhesion sections (the retainer plates  31 ) and the low adhesion sections formed by the interpolating bars  23  in the leading end application region  33  are not limited to an arrangement wherein they are smaller in surface area than the sheet member  12 , as in the conventional suction holes. Thus, the high adhesion sections and the low adhesion sections can be made larger in surface area than the sheet member  12  so as to ensure that the leading end of the sheet member  12  is positively held in place, over the entire regions, particularly by the adhesion force of the high adhesion sections in the form of the retainer plates  31 , without causing deformation.  
      Subsequently, after the transfer drum  11  has been rotated by an amount corresponding to the width of the narrow strip member  13 , a new narrow strip member  13  is applied to the application region of the transfer drum  11  corresponding to the new narrow strip member  13 , so as to extend in the axial direction with its side edge in tight contact with the corresponding side edge of the previous narrow strip member  13 . Such step is repeated multiple times, the number of which corresponds to the nominal rim diameter of the product tire minus one, so as to form a sheet member  12  on the outer peripheral surface of the transfer drum  11 . On this occasion, since the projections  43   b  of the retainer bars  43  as the high adhesion sections are flush with the outer cylinder  17  as the low adhesion sections, the sheet member  12  is intensively adhered to the radially outer surfaces of the projections  43   b  by adhesion force, so that the sheet member  12  as a whole, which has been applied to the outer peripheral surface of the transfer drum  11 , can be positively retained by the transfer drum  11 .  
      On this occasion, furthermore, the projections  43   b  of the retainer bars  43  are situated at the boundaries between the adjacent narrow strip members  13 . When the sheet member  12  is retained by the transfer drum  11  under such condition, as mentioned above, the sheet member  12  is adhesively retained in particular by the high adhesion sections (the retainer plates  31  and the retainer bars  43 ), so as to prevent formation of suction traces (deformations) over a wide range as in the prior art.  
      Subsequently, the transfer drum  11  adhesively retaining the sheet member  12  on the high adhesion sections (the retainer plates  31  and the retainer bars  43 ) is moved toward the receiver drum  51 . In this instance, since the sheet member  12  as a whole is intensively retained by the transfer drum  11  as mentioned above, the sheet member  12  is effectively prevented from separation from the transfer drum  11  or dislocation. As soon as the transfer drum has been moved to the transfer position and brought into contact with the receiver drum  51 , the leading end of the sheet member  12  is urged by the transfer drum  11  against the leading end application region  52  of the receiver drum  51 .  
      On this occasion, the cylinders  35  are operated so that the piston rods  36  are retracted to their stroke ends, so that the high adhesion sections in the form of the radially outer surfaces of the retainer plates  31  are moved radially inwards from the outer peripheries of the interpolating bars  23 . BY this, the leading end of the sheet member  12  is now retained solely by the low adhesion section in the form of the interpolating bars  23 . On the other hand, as explained above, the leading end application region  52  of the receiver drum  51  in contact with the transfer drum  12  is formed as a mirror-finished surface. Therefore, the leading end of the sheet member  12  is transferred to the receiver drum  51  which now exhibits stronger adhesion force. At the same time, the vacuum source is operated to apply vacuum to the vacuum chamber  55  and the vacuum passages  56 , so that the leading end of the sheet member  12  is attracted by vacuum to the receiver drum  51  to ensure that the transfer of the leading end is positively achieved.  
      With the transfer drum  11  urged against the receiver drum  51 , the transfer drum  11  and the receiver drum  51  are rotated in opposite directions. During the rotation of these drums  11 ,  51 , each time the retainer bars  43  successively reach the line connecting the axes of the drums  11 ,  51 , the relevant retainer bars  43  are successively moved by the cylinders  45  radially inwards from the outer peripheral surface of the outer cylinder  17 . As a result, the remaining regions of the sheet member  12  in contact with the transfer drum  11  only at the low adhesion sections (the outer cylinder  17 ) are readily separated and removed from the transfer drum  11  and successively transferred onto the outer peripheral surface of the receiver drum  51 .  
      Furthermore, upon the above-mentioned transfer, since the low adhesion sections (the interpolating bars  23  and the outer cylinder  17 ) are formed of a resilient material, in particular silicone rubber, at least in the outer surface portion, even when the distance between the transfer drum  11  and the receiver drum  51  is less than zero, the sheet member  12  can be transferred from the transfer drum  11  to the receiver drum  51  under resilient deformation of the outer surface portion (silicone rubber) of the interpolating bars  23  and the outer cylinder  17 , to thereby facilitate the adjustment of the distance between these drums. After the entirety of the sheet member  12  has been transferred from the transfer drum  11  onto the receiver drum  51 , the rotation of the transfer drum  11  and the receiver drum  51  is stopped.  
      The basic concept of the present invention has been described above with reference to an embodiment wherein the moving means  38 ,  48  for moving the high adhesion sections (the retainer bars  43 ) in each adhesion region radially inwards are comprised of cylinders  35 ,  45  provided for the respective high adhesion sections. It would be desirable if the cylinders corresponding in number to the application regions are not required and the transfer device can be further simplified in structure. The present invention further provides an advanced embodiment of the sheet member transfer device with a simplified structure, which will be explained below with reference to  FIG. 5 .  
      In  FIG. 5 , reference numeral  62  denotes a rotary cam which is rotatably supported, through a bearing  61 , by the main shaft  15 . The rotary cam  62  is coaxial to the main shaft  15  and is of substantially sector shape. Reference numeral  63  denotes cam followers each pivoted to the radially inner end of the above-mentioned support bar  29 , and reference numeral  64  denotes cam followers each pivoted to the radially inner end of the retainer bar  43  that is situated between the support bar  29  and the retainer bar  43  which, in turn, is spaced from the support bar  29  on the rotational rear side by a predetermined number. The cam followers  63  and  64  provided for the support bars  29  and the retainer bars  43  make it possible to eliminate the cylinders  35 ,  45  as in the previously explained basic embodiment, so as to simplify the structure of the transfer device as a whole.  
      Here, the above-mentioned given number is a number (e.g. 14) which corresponds to the nominal value ( 15 ) of the minimum rim diameter (e.g., 15 inches) for the pneumatic tire to be formed from the sheet member  12 , minus a small integer, i.e., 1 in the illustrated embodiment. The rotary cam  62  has a radially outer edge which is formed with cam holes  65 ,  66  to be inserted by the cam followers  63 ,  64 , which cam holes are spaced in the circumferential direction from each other, by the same distance as the distance between the cam followers  63 ,  63  and the cam followers  64 ,  64 . These cam holes  65 ,  66  are inclined toward the front side in the rotational direction and radially inwards. As a result, when the rotary cam  62  is rotated forwards in the rotational direction, the cam followers  63 ,  64  are moved radially outwards so that the retainer plates  31  and the retainer bars  43  are flush with the outer peripheral surface of the outer cylinder  17 . On the other hand, when the rotary cam  62  is rotated rearwards in the rotational direction, the cam followers  63 ,  64  are moved radially inwards so that the retainer plates  31  and the retainer bars  43  retracted from the outer peripheral surface of the outer cylinder  17 .  
      Reference numeral  67  denotes cylinders each having a cylinder head connected to the relevant support disc  16 , and a piston rod  68  of which the tip end is connected to the front end of the rotary cam as seen in the rotational direction. As a result, when the cylinder  67  is operated and the piston rod  68  is retracted, the rotary cam  62  is rotated forwards in the rotational direction. On the other hand, when the piston rod  68  is extended, the rotary cam  62  is rotated rearwards in the rotational direction. Other elements of the advanced embodiment are essentially the same as those in the basic embodiment.  
      When the transfer drum  11  is applied to form a sheet member  12  for a pneumatic tire of which the nominal rim diameter is 18 inches, for example, as explained with reference to the basic embodiment, eighteen narrow strip members  13  are successively applied to the outer peripheral surface of the transfer drum  11  while intermittently rotating the transfer drum  11  by an amount corresponding to the width of the narrow strip member  13 .  
      Then, the transfer drum  11  is moved toward the receiver drum  51  until they are brought into contact with each other, and the leading end of the sheet member  12  is urged against, and transferred onto the leading end application region  52  of the receiver drum  51 . The piston rod  68  of the cylinder  67  is extended to rotate the roatry cam  62  rearwards in the rotational direction, so that the retainer plate  31  and the retainer bars  43  are moved radially inwards from the interpolating bars  23  and the outer cylinder  17 . As a result, the sheet member  12  is adhesively retained with its leading end the trailing end highly precisely positioned by the receiver drum  51  and five retainer bars  43  (the high adhesion sections). However, the remaining center portion is only in contact with the low adhesion sections in the form of the outer cylinder  17  and may thus undergo a slight displacement.  
      Subsequently, the transfer drum  11  and the receiver drum  51  are rotated in the opposite directions so that the sheet member  12  is progressively transferred form the transfer drum  11  to the receiver drum  51 . On this occasion, since the center portion is only in contact with the outer cylinder  17 , even if an external force is applied to the sheet member  12 , the sheet member  12  is displaced to absorb the external force, without causing wrinkles or entrapment of air. After the leading end of the sheet member  12  has reached the receiver drum  51 , each time the retainer bars  43  successively reach the line connecting the axes of the drums  11 ,  51 , the relevant retainer bars  43  are successively moved by the cylinders  45  radially inwards from the outer peripheral surface of the outer cylinder  17 . As a result, the remaining regions of the sheet member  12  are successively transferred to the receiver drum  51 . Other functions of the advanced embodiment are essentially the same as those in the basic embodiment.  
      In the embodiments described above, silicone rubber has been used to form the low adhesion sections. However, according to the present invention, if a resilient deformability is not required for the low adhesion sections, there may be used other materials such as plastic materials. Furthermore, in the embodiments described above, the high adhesion sections are formed as mirror-finished surfaces obtained by plating. However, according to the present invention, the mirror-finished surfaces may be formed by high precision polishing or the like. Moreover, in the embodiments described above, the retainer plate  31  and a plurality of the retainer bars  43  (thirteen in number) are radially moved by the rotary cam  62  integrally. However, according to the present invention, the arrangement may be such that the retainer plate is moved by a cylinder independently of the retainer bars, and the plurality of retainer bars are radially moved by the rotary cam integrally.  
      In the above description, the cam followers  63 ,  64 , the rotary cam  62  and the cylinder  67  as the cam drive means for rotating the rotary cam in the circumferential direction of the transfer drum, as a whole, constitute the collective radial expansion/contraction means for radially inwardly moving the high adhesion sections corresponding to the leading end application region and the adjacent application regions. Furthermore, the collective radial expansion/contraction means and the cylinder  45  as the moving means for radially inwardly moving the individual high adhesion sections corresponding to the application region for applying the trailing end of the sheet member  12 , as a whole, constitute the radial expansion/contraction means for moving the adhesion sections at the entire application regions. Such arrangement of the radial expansion/contraction means makes it possible to realize a simple structure of the transfer device, which serves to positively retain the narrow strip members  13  upon their application, and allows the sheet member  12  to be transferred without dislocations by positively retaining at least the leading end and the trailing end.  
     INDUSTRIAL APPLICABILITY  
      The present invention can be generally applied to industrial fields involving a transfer device wherein a sheet member is transferred from a transfer drum onto a receiver drum.