Patent Publication Number: US-6702094-B2

Title: Passenger conveyor device

Description:
TECHNICAL FIELD 
     The present invention relates to a passenger conveyer system such as an escalator, a moving walkway, or the like, in particular, to a passenger conveyer system for a long moving distance. 
     BACKGROUND ART 
     An escalator that is an example of the passenger conveyer system comprises a plurality of footsteps, each of which is provided with guide rollers in the front and the rear thereof. The plurality of footsteps is supported by engaging each of their guide rollers with a footstep guide rail provided in a structure. The footsteps move in a horizontal direction around the way in and the way out while keeping level, and move in an upward or a downward direction inclined at an angle of about thirty degrees on the way between the way in and the way out. 
     In general, the plurality of footsteps is connected to one another by means of a chain, and all the footsteps are moved continuously in synchronization with one another by driving the chain. 
     A driving unit that drives the chain employs a type of device that drives an end of the chain by means of a sprocket. The driving unit is provided around the way in or the way out. However, in regard to an escalator employing high footsteps, the load imposed on the chain is too large. Therefore, a sufficient driving force may not be transmitted by only driving the end of the chain in some cases. Such a problem is not limited to the escalator, but is a common one to passenger conveyer systems of long moving distances on the whole. 
     DISCLOSURE OF THE INVENTION 
     An object of the present invention is to provide a passenger conveyer system that is capable of applying sufficient driving force in the middle section of the chain and suitable for an escalator of high footsteps, a walkway of long moving distance, or the like. 
     To achieve the above object, a passenger conveyer system according to the invention comprises: 
     a footstep guide rail provided in a structure; 
     a plurality of footsteps which move along the footstep guide rail; 
     a chain which connects the plurality of footsteps with one another in an endless circular manner; and 
     a trochoid mechanism having a rocking unit, the mechanism including pin rollers which relatively drive linearly in accordance with the rock of the rocking unit and a trochoid tooth-shaped section which meshes with the pin rollers, the pin rollers and the trochoid tooth-shaped section disposed between the chain and the rocking unit. 
     In the passenger conveyer system according to the invention, the trochoid tooth-shaped section and the pin rollers move linearly at uniform velocity by one pitch of the pin rollers, and the footsteps can be moved forward accordingly through the chain. In such a mechanism, the mechanism, which drives by means of a chain, in itself has a function as a decelerator, which can combine two mechanism elements, such as a decelerator indispensable to a conventional driving mechanism and a chain driving transmission mechanism, into one driving mechanism. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram schematically showing the structure of a passenger conveyer system according to the first embodiment of the invention; 
     FIG. 2 is a diagram schematically showing the structure of a chain for the passenger conveyer system shown in FIG. 1; 
     FIG. 3 is a schematic illustration showing the detail of a driving mechanism section for the passenger conveyer system shown in FIG. 1; 
     FIG. 4 is a diagram for explaining the principle of operation concerning pin roller rolling gear teeth and pin rollers; 
     FIG. 5 is a schematic illustration showing the detail of a driving mechanism section for a passenger conveyer system according to the second embodiment of the invention; 
     FIG. 6 is a schematic illustration showing the detail of a driving mechanism section for a passenger conveyer system according to the third embodiment of the invention; 
     FIG. 7 is a diagram for explanation, showing positions of each pin roller rolling gear teeth during one rotation of an eccentric crankshaft; 
     FIG. 8 is a diagram for explanation, showing the movement of each pin roller rolling gear teeth during one rotation of an eccentric crankshaft and a positional relation between a footstep guide rail and a back supporting plate; 
     FIG. 9 is a diagram schematically showing the structure of a passenger conveyer system according to the fourth embodiment of the invention; 
     FIG. 10 is a diagram for explaining the balance of force applied to a chain in the passenger conveyer system shown in FIG. 9; 
     FIG. 11 is a cross-sectional view of the driving mechanism shown in FIG. 9; 
     FIG. 12 is a diagram schematically showing the structure of a passenger conveyer system according to the fifth embodiment of the invention; 
     FIG. 13 is a perspective view showing the structure of back supporting rollers which back and support a chain in a passenger conveyer system according to the sixth embodiment of the invention; 
     FIGS. 14A and 14B are cross-sectional views showing the details of the back supporting roller shown in FIG. 13; 
     FIG. 15 is a perspective view showing a back supporting circular wire rope component which backs and supports a chain in a passenger conveyer system according to the seventh embodiment of the invention; and 
     FIG. 16 is a cross-sectional view of the back supporting circular wire rope component shown in FIG.  15 . 
    
    
     BEST MODE FOR CARRYING OUT OF THE INVENTION 
     Embodiments of the present invention now will be described with reference to the accompanying drawings. 
     FIG. 1 is a diagram schematically showing the structure of a passenger conveyer system according to the first embodiment of the invention. As shown in FIG. 1, the passenger conveyer system  20  according to the first embodiment of the invention is constructed as an escalator. The passenger conveyer system  20  comprises a footstep guide rail  4  provided for a structure  120  in a circular way and a plurality of footsteps  2 , which move along the footstep guide rail  4 . The footstep guide rail  4  according to the present embodiment is constituted by a pair of parts, each of which has a C-shape section with its opening section faced toward the inside. (Refer to FIG. 3.) 
     The plurality of footsteps  2  are connected to one another by a pair of chains  5  (in the front side chain  5  and the rear side chain  5  from a plane view in FIG. 1) having pin rollers  5   a  on both sides in a direction right-angled to the longitudinal direction of the chains  5 , i.e., a cross direction of the chains  5  and thus constructed annularly. As shown in FIG. 2, the pin rollers  5   a  are attached freely in rotating by a pitch P, i.e., at regular intervals to the chain  5 . The pin rollers  5   a  constitute a trochoid mechanism together with a rocking plate  10  and pin roller rolling gear teeth  11 . 
     The pin rollers  5   a  according to the embodiment engage with the footsteps guide rails  4 , thereby guiding the footsteps  2  along the footsteps guide rail  4 . That is, the pin rollers  5   a  also serve as guide rollers in the front section of the footsteps  2 . However, guide rollers  50  in the rear section of the footsteps are formed larger in diameter than the pin rollers  5   a  and run on rear wheel guide rails  40  provided for the structure  120 . (Refer to FIG. 3.) 
     Three driving mechanisms  1   a ,  1   b , and  1   c  used for transmitting driving force to the chains  5  are arranged separately in the middle section of the footstep guide rails  4 , more specifically, at a predetermined section other than end sections of the footstep guide rails  4 , where the footstep guide rails  4  change their direction so as to turn up and down. The footstep guide rails  4  are partially eliminated in the sections where the driving mechanisms  1   a ,  1   b , and  1   c  are disposed. 
     FIG. 3 is a detailed view of the driving mechanism  1   a . The structures of the other driving mechanisms  1   b  and  1   c  are substantially the same as one of the driving mechanism  1   a  shown in FIG.  3 . Therefore, the description will be given for only the driving mechanism  1   a  and omitted for the driving mechanisms  1   b  and  1   c.    
     As shown in FIG. 3, the driving mechanism  1   a  has an electric motor  18  (rotary driving device) installed in the structure  120 . The electric motor  18  is capable of generating driving force and suspension holding power. An eccentric crankshaft  6  is connected to the electric motor  18  through a reduction mechanism  61  constituted by gear teeth. To the eccentric crankshaft  6 , eccentric discs  8  are connected with eccentricity δ (δ 1  to δ 8 ). So the eccentric discs  8  rotate eccentrically around the shaft center of the eccentric crankshaft  6  with eccentricity δ. 
     In the embodiment, in addition to the eccentric crankshaft  6 , there are provided two idler eccentric crankshafts  7  to which eccentric discs  9  are attached. The eccentric discs  9  eccentrically rotate subordinately with the same eccentricity δ as one for the eccentric discs  8 . 
     To each of the eccentric discs  8  of the eccentric crankshaft  6 , four rocking plates  10  ( 10   a  to  10   d ) are connected serving as a rocking unit that rock in accordance with the eccentric rotation of the eccentric disc  8 . The four rocking plates  10  are disposed such that the relevant rocking plates are divided in pairs and disposed in the front and the rear in an extended manner in a longitudinal direction, i.e., in a circular direction of the chain  5 . The two rocking plates  10  disposed in a forward extended manner are connected to the eccentric disc  9  attached to one of the idler eccentric crankshaft  7 . The two rocking plates  10  disposed in a backward extended manner are connected to the eccentric disc  9  of the other idler eccentric crankshaft  7 . The respective rocking plates  10  are supported freely in rotating to the eccentric crankshaft  6  and the idler eccentric crankshafts  7 . 
     In addition, the relative positioning relation between the four rocking plates  10  is arranged in that a phase shift of 90° is allotted equally for an eccentric angle between the four rocking plates. Further, in each of the four rocking plates  10 , there is provided a mass balance adjustment device  14 , which is capable of adjusting the weight and the fixing position of small additional weights  14   a.    
     Trochoid-shaped pin roller rolling gear teeth  11  ( 11   a  to  11   d ) are attached detachably on the top and the bottom of the respective rocking plates  10 . In FIG. 3, the structures at the bottom of the rocking plates  10  are omitted for simplifying the drawing. The pin roller rolling gear teeth  11   a  to  11   d  are disposed such that the relevant pin roller rolling gear teeth mesh sequentially with the pin rollers  5   a  of the chain  5  in accordance with the rock of the rocking plates  10   a  to  10   d , thereby affording a thrust thereto. In the case of the embodiment, the pin roller rolling gear teeth  11  on the top and the of each rocking plate  10  mesh with both pin rollers  5   a  on an approach route side  15   a  and a return route side  15   b  (See FIG. 1) of the chains  5  that circulates back and forth, respectively, thereby affording a thrust thereto. The corners of each pin roller rolling gear teeth  11  are formed round so as to prevent concentrated stress from occurring. 
     In the case of this embodiment, in each rocking plate  10 , there is provided a position fine adjustment function  13 , which is capable of adjusting a mounting position, in which the pin roller rolling gear teeth  11  is mounted on the relevant rocking plate  10 , in a circular direction of the chain  5 . The position fine adjustment function  13  may be formed simply by, for example, a long hole and a bolt, etc. 
     In the structure  120  such as a truss structure, there are provided back guiding plates  12 , which guide the pin rollers  5   a  on the reverse sides to the sides where the pin roller rolling gear teeth  11  are located with respect to the pin rollers  5   a  (the upper side in the approach route shown in the drawing, and the lower side in the return route not shown in the drawing). The back guiding plates  12  are disposed such that one back guiding plate corresponds to the rocking plates  10  that are disposed in pairs in the front and the rear in the circular direction of the chains  5 . 
     The back guiding plates  12  are designed such that the back guiding plates can be translated in the circular direction of the chains  5  in accordance with the frictional force against the pin rollers  5   a , which are in contact with, by the quantity of travel equal to or less than the eccentricity δ of the eccentric discs  8  against the eccentric crankshaft  6 , while interposing the pin rollers  5   a  between the rocking plates  10  and themselves. For the back guiding plates  12 , there are provided back guiding plate restoring devices  17 , which restore the translated back guiding plates  12  to their original positions. The back guiding plates  12  are formed so hard as not to damage the pin rollers  5   a  and can be replaced. 
     Next, the action according to the embodiment constructed as the above will be described with reference to FIG.  4 . FIG. 4 is a diagram for explaining the principle of movement concerning the rocking plate  10 , the trochoid-shaped pin roller rolling gear teeth  11  and the pin rollers  5   a , these constituting the trochoid mechanism. 
     The pin rollers  5   a  of the chain  5  are attached by the pitch P at regular intervals, as described above. The back guiding plates  12  support the back faces of the pin rollers  5   a  from the reverse sides to the pin roller rolling gear teeth  11 . 
     In this state, the electric motor  18  is driven so that the eccentric disc  8  is rotated eccentrically working with the rotations of the toothed gear  61  and the eccentric crankshaft  6 , as shown in FIG.  4 . Then, the eccentric disc  9  of the idler eccentric crankshaft  7  is subordinately rotated eccentrically with the same eccentricity δ as one of the eccentric disc  8 . Accordingly the rocking plate  10  rocks while keeping parallel to the circular direction of the chain  5 . By this rocking movement, the trochoid-shaped pin roller rolling gear teeth  11  ( 11   a  to  11   d ) mesh sequentially with the pin rollers  5   a , and thus the four rocking plates  10  ( 10   a  to  10   d ) transmit a thrust continuously to the pin rollers  5   a . Accordingly, the pin rollers  5   a  move forward at uniform velocity, without unevenness in velocity. In this case, with one rotation of the eccentric crankshaft  6 , the pin rollers  5   a  proceed by one pitch P. 
     When the rocking plates  10  rock continuously, the pin roller rolling gear teeth  11  give a thrust to the chain  5  through the pin rollers  5   a . Accordingly, two chains  5  are driven and then the footsteps  2  are moved. Incidentally, it is possible to use an inexpensive geared motor with a one-stage toothed gear as the electric motor  6 . In this case, the reduction mechanism  61  for the electric motor  6  can be omitted. 
     On transmitting the thrust to the pin rollers  5   a , the pin roller rolling gear teeth  11  also gives a force to the pin rollers  5   a  in a direction other than the moving direction (circular direction of the chains  5 ). However, since the guide rails  4  are formed from members having a C-shape in section, the pin rollers  5   a , i.e., the footsteps  2  move smoothly. In addition, if the pin roller rolling gear teeth  11  are mounted detachably on the rocking plates  10 , only pin roller rolling gear teeth  11  need be detached from the rocking plates  10  for replacement. That enables mass production of only the pin roller rolling gears  11 . As a result, maintenance expenses can be reduced. Obviously, the pin roller rolling gear teeth  11  can be formed integrated with the rocking plate  10 . 
     In addition, it is possible to amend an error in mounting the pin roller rolling gear teeth  11  in each of the separately disposed driving mechanisms  1   a ,  1   b , and  1   c  with use of the position fine adjustment function  13  shown in FIG.  3 . 
     Further, the pin roller rolling gear teeth  11  according to the embodiment are arranged pairs separately in the front and the rear in the circular direction of the chain  5 , and the pair of the pin roller rolling gear teeth  11  presses the pin rollers  5   a  of limited width L. Therefore, a treatment of rounding the corners, or the like can be sufficiently applied to the pin roller rolling gear teeth  11  in comparison with the case where the four pin roller rolling gear teeth  11  are formed further thinner and made into one unit. Accordingly, it is possible to relieve generation of the concentrated stress caused by edge portions. In addition, the thickness of the pin roller rolling gear teeth  11  is secured. Therefore, the strength of the pin roller rolling gear teeth  11  can also be secured. As a result, durability and reliability of the pin roller rolling gear teeth  11  can be improved. 
     Additionally, an angle of 90° is allotted equally as the phase shift of the eccentric angle for each of the four rocking plates  10   a  to  10   d . Therefore, the whirling force between the rocking plates  10   a  to  10   d  is canceled so that the generation of vibration can be relieved. In the case where the vibration occurs, the weight and mounting position of the small additional weight  14   a  is changed in the mass balance adjustment device  14  shown in FIG.  3 . Then, it is possible to adjust the mass balance easily. Accordingly, mechanical damage such as a fatigue failure caused by vibration can be suppressed. 
     Incidentally, according to the embodiment, the pin roller rolling gear teeth  11  are provided on both the top and the bottom of the rocking plate  10 . Therefore, the pin roller rolling gear teeth  11  can give thrusts to the pin rollers  5   a  on both the approach route side  15   a  and the return route side  15   b  of the chain  5  that circulates back and forth. Thus, excellent driving force transmission efficiency can be obtained. In this case, the pin roller rolling gear teeth  11  only needs to be provided on one side of the rocking plate  10 . 
     The back guiding plate  12  is formed from a material having a hardness to wear out prior to the pin rollers  5   a , thereby not damaging the pin rollers  5   a . Thus the frequency of replacing the chains  5  is reduced. In addition, independent parts constitute the exhausted back guiding plates  12  so that they can be replaced easily with new ones. 
     Further, while the pin roller rolling gear teeth  11  of the rocking plates  10  are pressing the pin rollers  5   a , the back guiding plates  12  on the back of the pin rollers  5   a  are translated together with the pin rollers  5   a  without any slip. When the pin roller rolling gear teeth  11  of the rocking plates  10  leave from the pin rollers  5   a , the back guiding plates  12  return to the original positions by the pressure supplied by the back guiding plate restoring devices  17 . Therefore, in the back guiding plates  12 , abrasion caused by rock can be prevented from occurring and further, durability and reliability are improved. 
     Incidentally, the passenger conveyer system  20  according to the embodiment is constructed as an escalator. However, it can be also constructed for a level moving walkway. 
     Next, the passenger conveyer system according to the second embodiment of the invention will be described with reference to FIG.  5 . FIG. 5 is a schematic illustration showing a driving mechanism  21  for the passenger conveyer system according to second embodiment of the invention. 
     As shown in FIG. 5, in the passenger conveyer system  20  according to the present embodiment, the chain  5  is constructed by connecting a number of paired links  5   b , each having the length of one pitch of the footstep  2 . At the front end of each link  5   b , a guide roller  24  is provided separately from the pin rollers  5   a . Four of the pin rollers  5   a  are attached between the respective paired links  5   b  with the relation of layout in which the pin rollers  5   a  are allotted equally when the links  5   b  are arranged in a straight line. 
     The footstep guide rail  4  is engaged with only the guide rollers  24 . The pin rollers  5   a  of the chain  5  do not engage with the footstep guide rail  4 . The footstep guide rail  4  has a C-shape in section and the guide rollers  24  roll on the inside thereof. Therefore, movement of the guide rollers  24  in a vertical direction can be controlled. As a result, the footstep guide rail  4  functions as a back guiding plate that guides the pin rollers  5   a  of the chain  5  on the reverse side to the side where the pin roller rolling gear teeth  11  are located. 
     The other structures are substantially the same as ones according to the first embodiment shown in FIGS. 1 to  3 . In the second embodiment, the identical sections to the first embodiment shown in FIGS. 1 to  3  are marked with the identical symbols, and detailed descriptions will be omitted. 
     According to the present embodiment, since the link  5   b  of the chain  5  has a length equal to one pitch of the footstep  2 , the number of links can be reduced, at the same time, the number of portions where the pin rollers  5   a  mesh with the pin roller rolling gear teeth  11  can be increased easily by increasing the number of the pin rollers  5   a . Therefore, the velocity reducing ratio (reduction ratio) using a trochoid tooth form can be improved easily. 
     Next, the passenger conveyer system according to the third embodiment of the invention will be described with reference to FIG.  6 . FIG. 6 is a schematic illustration showing a driving mechanism  41  for the passenger conveyer system according to third embodiment. 
     As shown in FIG. 6, in a passenger conveyer system  30  according to the embodiment, pin roller rolling gear teeth  31  of the trochoid tooth form are formed in the links  5   b  of the chain  5 . At the top and bottom ends of the rocking plates  10 , there are provided eccentric rocking pin rollers  32   a  that give thrusts to the pin roller rolling gear teeth  31  in accordance with the rocking of the rocking plates  10 . 
     The other structures are the substantially the same as ones according to the second embodiment shown in FIG.  5 . In the third embodiment, the identical sections to the second embodiment shown in FIG. 5 are marked with the identical symbols, and detailed descriptions will be omitted. 
     According to the present embodiment, the difference from the second embodiment is only that the pin rollers  32   a  and the pin roller rolling gear teeth  31  are mounted in the reverse manner, and the passenger conveyer system in this embodiment acts in the substantially same manner as the one in the second embodiment. 
     Next, with respect to the driving mechanism common to the passenger conveyer systems according to the first, second, and third embodiments described above, the allocation of eccentric phase angles of the respective rocking plates  10   a  to  10   d  connected to the eccentric crankshaft  6  and the arrangement of the pin roller rolling gear teeth  11   a  to  11   d  will be described in further detail. The basis constituting components of the driving mechanism are common to ones of the driving mechanism  1   a  shown in FIG. 3, and thus these components will be described with identical symbols to FIG.  3 . 
     FIG. 7 is a diagram showing changes of the meshing position of the pin rollers  5   a  during one rotation of the crankshaft  6 , against the pin roller rolling gear teeth  11   a  to  11   d , which are mounted on the rocking plates  10   a  to  10   d , respectively, disposed as shown in FIG.  3 . 
     Each of the pin roller rolling gear teeth  11   a  to  11   d  has the identically shaped trochoid tooth form. That aims to reduce the production cost for the complicated trochoid tooth form. However, in order to engage the pin roller rolling gear teeth  11   a  to  11   d  with the pin rollers  5   a  and move the chain  5  smoothly by the distance equal to the pitch P of the pin roller rolling gear teeth during one rotation of the eccentric crankshaft  6 , it is designed that the phases of the trochoid tooth forms are not overlapped with one another and thus the meshing positions of the pin roller rolling gear teeth with the pin rollers  5   a  are changed. 
     More specifically, the eccentric phase angles of the rocking plates  10   a ,  10   b ,  10   c , and  10   d  are shifted mutually by 90°. Assuming the difference of each eccentric phase angle of the rocking plates  10   b ,  10   c , and  10   d  against the rocking plate  10   a  as reference to be ΔΦi, each phase of the trochoid tooth forms in the pin roller rolling gears teeth  11   a  to  11   d  that are mounted on the rocking plates  10   a ,  10   b ,  10   c  and  10   d  are shifted by Δp=P×ΔΦi/360 toward the proceeding direction of the chain  5  in regard to the relative positioning relation against the pin rollers  5   a . (P denotes the pitch of the trochoid tooth form. In this case, P is equal to the pitch of the chain  5 .) 
     If the above is described specifically in accordance with FIG. 7, that will be described as follows. FIG.  7 ( a ) shows the respective positions of the pin roller rolling gear teeth  11   a  to  11   d  when the rotation angle of the eccentric crankshaft  6  is at 0° or 360°. Assume that the pin roller rolling gear teeth  11   a  is used as reference. In this case, the phase of the trochoid tooth form of the pin roller rolling gear teeth  11   b  having the difference of the eccentric phase angle of 90° from the reference is shifted by P×¼ (P×90/360) toward the proceeding direction of the chain against the trochoid tooth form of the pin roller rolling gear teeth  11   a , as far as the relative position to the pin rollers  5   a  is concerned. In the same manner, in regard to the relation between the pin roller rolling gear teeth  11   b  and the pin roller rolling gear teeth  11   c , the difference of the eccentric phase angle is 90°. Therefore, the phase shift of the trochoid tooth form concerning the relative position to the pin rollers  5   a  is P×½ (P×180/360). In regard to the pin roller rolling gear teeth  11   d , the phase shift is P×¾ (P×270/360). 
     Such relative phase shifts between the trochoid tooth forms and the pin rollers  5   a  are not changed in the cases where the rotation angle of the eccentric crankshaft  6  is at 90° (FIG.  7 ( b )), 180° (FIG.  7 ( c )), or 270° (FIG.  7 ( d )). Therefore, during one rotation of the eccentric crankshaft  6 , the respective pin roller rolling gear teeth  11   a  to  11   d  can smoothly move the chain  5  by the pitch P at uniform velocity while continuously changing their meshing positions to the pin rollers  5   a  in accordance with the rock of the rocking plates  10   a  to  10   d.    
     In the driving mechanism constructed as the above, since the respective units, i.e., the unit of the rocking plates  10   a  and  10   c , and the unit of the rocking plates  10   b  and  10   d , are disposed separately in the front and the rear, inertial force in the rocking movement is canceled mutually. Therefore, the inertial force does not act as excitation force to the eccentric crankshaft  6  and the idler eccentric crankshafts  8 . As a result, it is possible to restrain vibration or noise from occurring. 
     The above description relates to the phase shift in the proceeding direction of the chain in the trochoid tooth forms of the pin roller rolling gear teeth  11   a  to  11   d . In order to add the appropriate thrust to the pin rollers  5   a  with the rock of the pin roller rolling gear teeth  11   a  to  11   d , it is necessary that the pin rollers  5   a  are guided appropriately by the footstep guide rails  4  or the back guiding plates  12 , and the pin roller rolling gear teeth  11   a  to  11   d  do not interfere with the footstep guide rails  4  or the back guiding plates  12 . For this reason, the footstep guide rails  4  and the back guiding plates  12  now will be described in detail with reference to FIG.  8 . 
     FIG. 8 is a diagram for explaining a positioning relation between the footstep guide rail  4  and the back guiding plate  12  in regard to the unit of the pin roller rolling gear teeth  11   a  and  11   c  among the pin roller rolling gear teeth  11   a  to  11   d.    
     As shown in FIG. 3, the footstep guide rail  4  is a guide rail of hook-shape in section, whose upper guide section  4   a  and lower guide section  4   b  are used as rolling guide ways for the pin rollers  5   a.    
     FIG.  8 ( a ) is a plan view of the upper guide section  4   a  with the footstep guide rail  4  viewed from above, and FIGS.  8 ( b ) to  8 ( e ) show the movement of the pin roller rolling gear teeth  11   a  and  11   c  when the eccentric crankshaft  6  is rotated 90° by 90°. FIG.  8 ( f ) is a plan view showing the lower guide section  4   b  of the footstep guide rail  4 . Incidentally, the unit of the pin roller rolling gear teeth  11   b  and  11   d  is similar to the unit of the pin roller rolling gear teeth  11   a  and  11   c , and is thus omitted in FIG.  8 . 
     In the footstep guide rail  4 , a disconnect section is provided so as not to locate precisely over the pin roller rolling gear teeth  11   a  and  11   c . The pin roller rolling gear teeth  11   a  and  11   c  pass through the disconnect section of the footstep guide rail  4  and rock toward the top dead center and the bottom dead center. As shown in FIG.  8 ( f ), the pin roller rolling gear teeth  11   a  and  11   c  rock parallel to the footstep guide rail  4 . When the pin roller rolling gear teeth  11   a  is located in the top dead center or the bottom dead center, the phase difference exists by only P/2 in a longitudinal direction against the pin roller rolling gear  11   c . (P denotes the pitch of the trochoid tooth form.) (Refer to FIG.  8 ( c ) or FIG.  8 ( e ).) 
     For the purpose of preventing the footstep guide rail  4  from interfering with the pin roller rolling gear teeth  11   a  and  11   c  which rock with such phase difference, a stepped shape is formed in the lower guide section  4   b  of the footstep guide rail  4  such that relief sections  41   a  and  41   c  are formed at ends of the lower guide section, the ends opposing each other with the pin roller rolling gear teeth  11   a  and  11   c  interposed therebetween. The relief sections are formed by rectangularly notching parts of the respective ends of the lower guide section in an interlocked manner. It is preferable that the width of the respective relief sections  41   a  and  41   c  is half as much as the width of the lower guide section  4   b  and its length is at least P/2. In addition, as shown in FIG.  8 ( c ) and  8 ( e ), in the case where the pin roller rolling gear teeth  11   a  and  11   c  are located in the top dead center and the bottom dead center, respectively, it is set that the pin roller rolling gear teeth  11   a  and  11   c  overlap with the lower guide section  4   b  with 0.28 P in length to the maximum extent while leaving clearance of Δm in the relief sections  41   a  and  41   c.    
     Assuming the quantity of movement for the pin roller rolling gear teeth  11   a  and  11   c  in the proceeding direction of the chain  5  to be ±δm, the δm can be ±0.159P to the maximum extent in proceeding from FIG.  8 ( b ) to FIG.  8 ( d ) in the relation to the pitch P. Accordingly, while the pin roller rolling gear teeth  11   a  and  11   c  are rocking, the clearance Δm is assured. Therefore, the lower guide section  4   b  does not interfere with the pin roller rolling gear teeth  11   a  and  11   c , and further sections in which the lower guide section  4   b  overlaps with the pin roller rolling gear teeth  11   a  and  11   c  are assuredly secured. As a result, although there are disconnect sections in the footstep guide rail  4 , the pin rollers  5   a  of the chain  5  move smoothly without interruption from one end to the other end of the lower guide section  4   b  while riding on the pin roller rolling gear teeth  11   a  and  11   c.    
     On the other hand, as shown in FIG.  8 ( a ), in the upper guide  4   a  of the footstep guide rail  4  in addition to the above case, relief sections  42 , each having a predetermined length of ΔS, are formed at both end portions opposed to each other with the back guiding plate  12  interposed therebetween by rectangularly notching parts of the respective ends. In the case of the upper guide  4   a , rectangular relief sections  43  are also formed at the both end portions of the back guiding plate  12  in the same manner. The back guiding plate  12  is connected to the back guiding device  17  that returns the back guiding plate to the neutral position shown in FIGS.  8 ( b ) and  8 ( d ). The back guiding device  17  has a function of holding the position of a rod  17   c  by means of springs  17   a  and  17   b  having the elastic modulus equal to each other. While dragged by the pin rollers  5   a  that move by the rock of the pin roller rolling gear teeth  11   a  and  11   c , the back guiding plate  12  is translated. In this case, the back guiding plate  12  can be returned to the original neutral position by the elasticity of the springs  17   a  and  17   b.    
     More specifically, when the trochoid tooth forms of the pin roller rolling gear teeth  11   a  and  11   c  move so as to extrude the pin rollers  5   a  in such a process shown from the FIG.  8 ( b ) to FIG.  8 ( c ) or a process shown from FIG.  8 ( d ) to FIG.  8 ( e ), the back guiding plate  12  is dragged by the movement of the pin rollers  5   a  and thus moves in a translated manner by the quantity of travel δs. By this translated movement, the spring  17   a  of the back guiding plate restoring device  17  is compressed, and the spring  17   b  is pulled and stretched. 
     On the other hand, when the trochoid tooth forms of the pin roller rolling gears  11   a  and  11   c  simply roll and guide the pin rollers  5   a  in such a process shown from the FIG.  8 ( c ) to FIG.  8 ( d ) or a process shown from FIG.  8 ( e ) to FIG.  8 ( b ), the back guiding plate  12  does not receive a drag from the pin rollers. Therefore, the spring  17   a  of the back guiding plate restoring device  17  presses back the back guiding plate  12 , and the spring  17   b  pulls back the relevant plate. As a result, the back guiding plate  12  can return to the neutral position. 
     In addition, by setting the sizes of the relief sections  42  and  43  as follows, the upper guide section  4   a  of the footstep guide rail  4  and the back guiding plate  12  can overlap mutually in an interlocked manner without interfering with each other. 
     Assume that the length of the respective relief sections  42  and  43  is ΔS in the jointing section where the upper guide section  4   a  and the back guiding plate  12  overlap each other. And, assume that the width of the section, where the back guiding plate  12  located in the neutral position shown in FIG.  8 ( b ) or  8 ( d ) and the upper guide section  4   a  overlap with each other, is Δs. And further assume that the quantity of translated movement of the back guiding plate  12 , which is dragged by the pin rollers  5   a  moved by the rock of the pin roller rocking gear teeth  11   a  and  11   c  and thus moved in a translated manner together with the relevant rollers, is δs. Then, ΔS−Δs is set larger than the quantity of translated movement δs. By setting as the above, as shown in FIG.  8 ( c ), even when the back guiding plate  12  moves by δs from the natural position, a clearance is assured in the relief sections  42  and  43 . Therefore, the relief sections  42  and  43  can be prevented from interfering with each other and maintain the smooth movement. 
     Next, the passenger conveyer system according to the fourth embodiment will be described with reference to FIGS. 9 and 10. 
     FIG. 9 is a diagram schematically showing the structure of the passenger conveyer system according to the fourth embodiment of the invention. In the conveyer system  50  according to the fourth embodiment, the footstep guide rail  4  provided for the structure  120  and the plurality of footsteps  2  that move along the footstep guide rail  4  are the same as ones in the third embodiment described above. In addition, the plurality of footsteps  2  are connected circularly by a pair (in the front and the rear side from a plane view in FIG. 7) of the chains  5  having the pin rollers  5   a  in the same manner as one in the passenger conveyer system according to the first to third embodiments. And the driving mechanisms  1   a  and  1   b , which drive the chains  5 , are disposed separately at a predetermined interval in the middle section of the footstep guide rail  4 . The base structure of the respective driving mechanisms  1   a  and  1   b  is one common to the driving mechanism shown in FIG.  3 . Thus the identical constituting components are marked with the identical symbols, and detailed descriptions will be omitted. 
     The passenger conveyer system according to the fourth embodiment is constructed as an escalator that has gaps at its way in and the way out located on both ends of the structure. Housings  52   a  and  52   b  of the driving mechanisms  1   a  and  1   b  are arranged to the structure  120 , which inclines with the same inclination as the footstep guide rail  4 , through supporting sections  53   a  and  53   b  in a manner slidable in a moving direction of the footsteps  4 . 
     The constant force is applied to the whole of the driving mechanisms  1   a  and  1   b , which are arranged in a slidable manner, from the structure  120  side so that chain tension energization means  54   a  and  54   b , which increase tension of the chains  5 , are provided. In addition, at a lower turning section  55  of upper and lower reversal sections in the footsteps  2 , initial tension adding means  56  used for adding initial tension to the chains  5  is disposed. These chain tension energization means  54   a  and  54   b , and the initial tension adding means  56  are configured to energize tension of the chains  5  with use of elastic power of springs or the like and to eliminate looseness in a case where the initial slack occurs in the chains  5 . 
     FIG. 10 is a diagram showing a state of balance between forces, which affects the chains  5 , in the form of a model. In FIG. 10, as a matter of convenience for description, the reference symbol  57   b  denotes chains between the lower turning section and the lower driving mechanism  1   b , and the  57   a  denotes the sections of the chains upper than the driving mechanism  1   b.    
     In FIG. 10, at first, the balance between forces in regard to the lower driving mechanism  1   b  will be considered. The reference symbol Wbc denotes an inclination angle element of the weight of the chains  57   b ; the Wbd, an inclination angle element of the weight of the driving mechanism  1   b  itself; the Wini, initial tension to be applied from the initial tension adding means  56  to the chains  57   b ; and the W 1   b , an inclination angle element of the weight of passengers and loads, which affects the area between the lower turning section  55  and the driving mechanism  1   b . (The W 1   b  fluctuates depending on state of operation. Therefore, the W 1   b  will be referred to as fluctuating load weight, hereinafter.) These forces act downwards, in parallel to the chains  57   b.    
     Assume that Tb denotes the force that energizes the chains  57   b  upwardly and in parallel through the chain tension energization means  54   b  while the lower driving mechanism  1   b  drives the chains  57   b . Since this chain energization force Tb acts continuously, the tension of the chains  5  can be controlled as follows. 
     That is, the degree of the chain energization force Tb is set substantially equal to the inclination angle element Wbc of the weight of the chains  57   b  and to the angle inclination element Wbd of the weight of the driving mechanism  1   b . By doing this, it is possible to sustain the weight corresponding to the sum Wb of the inclination angle element Wbc of the weight of the chains  57   b  and the angle inclination element Wbd of the weight of the driving mechanism  1   b  through the chain tension energization means  54   b . (Since the sum Wb is fixed for each conveyer system, the relevant sum Wb will be referred to as fixed load weight, hereinafter.) As a result, no fixed load weight Wb is applied to the chains  57   a , which is located on the upper side than the driving mechanism  1   b . The tension acting on the chains  57   a  is substantially reduced to Wini+W 1   b , which is the sum of the initial tension Wini that is applied from the initial tension adding means  56  and the aforementioned fluctuating load weight W 1   b.    
     Further, in the case of the balance between the forces in regard to the upper driving mechanism  1   a  as well, the degree of the chain energization force Ta supplied from the chain tension energization means  54   a  is set substantially equal to the sum Wa of the inclination angle element Wac of the weight of the chains  57   a  and the angle inclination element Wad of the weight of the driving mechanism  1   a  itself. (Since the sum Wa is fixed for each conveyer system, the relevant sum Wba will be referred to as fixed load weight, hereinafter.) By doing this, it is possible to sustain the fixed load weight Wa, which is the sum of the inclination angle element Wac of the weight of the chains  57   a  and the angle inclination element Wad of the weight of the driving mechanism  1   a , through the chain tension energization means  54   a . Therefore, no fixed load weight Wa is applied to the chains  57   c , which is located on the upper side than the driving mechanism  1   a . As a result, the substantial effective tension can be reduced to the sum of Wini+W 1   b , which is brought above by the chains  57   a , and the fluctuating load weight W 1   a , which is the inclination angle element of the summed weight of passengers and loads between the driving mechanism  1   b  and the driving mechanism  1   a , that is Wini+W 1   a +W 1   b.    
     In short, on all of the chains  5 , the fixed load weight Wa and Wb is borne through the chain tension energization means  54   a  and  54   b , respectively, so that the load on the chains  5  can be reduced by the borne weight. Incidentally, the fluctuating load weight W 1   a  and W 1   b  are zero in the case of no load existing. Therefore, at least the initial tension Wini affects all of the chains  5 . 
     The above description is the embodiment in which the chain tension energization means  54   a  and  54   b  are provided additionally to the driving mechanisms  1   a  and  1   b  so as to reduce the load on the chains  5 . Next, FIG. 11 shows the driving mechanisms  1   a  and  1   b  in which the fluctuating load weight W 1   a  and W 1   b  are sustained through pin roller rolling gears. In this case, both the driving mechanisms  1   a  and  1   b  have the same structure and thus only the driving mechanism  1   a  will be described with reference to FIG.  8 . Incidentally, in FIG. 11, the identical reference symbols to FIG. 3 denote the same constituting components. 
     In FIG. 11, the Δt shows the distance between the axis of the eccentric crankshaft  6  and a chain  15   a  on the approach route side. And the Δr shows the distance between the axis of the eccentric crankshaft  6  and a chain  15   b  on the return route side. In this case, the Δt and the Δr are different from each other, and the distance Δr toward the return route side is longer. 
     A unit of pin roller rolling gear teeth  11  having the same trochoid form, two making one unit, is allocated on both the approach route side and the return route side in each rocking plate  10 . Each of the pin roller rolling gears  11  is attached to the rocking plate  10  so as to maintain mesh with the pin rollers  5   a . In this manner, in the driving mechanism in which the rocking movement of the rocking plates  10  is converted into a thrust for chains through the pin roller rolling gears, each gears having the trochoid forms, the relative position of an eccentric crankshaft  8  against the chain  15   a  on the approach route side and the chain  15   b  on the return route side can be set freely. Therefore, there is flexibility in designing, in particular, the size of the driving mechanism in its height direction can be easily reduced. 
     The inclination angle elements of the fixed load weight and the fluctuating load weight, both weights affecting the chain  15   b  on the return route side, can be sustained through the pin roller rolling gear teeth  11  on the approach route side. On the other hand, the inclination angle elements of the fixed load weight and the fluctuating load weight, both weights affecting the chain  15   a  on the approach route side, can be sustained through the pin roller rolling gear teeth  11  on the return route side. Thus, the entire weight of the chains  15   a  and  15   b  can be shared sustained by the pin roller rolling gears  11  on both the approach route side and the return route side. As a result, the load on the chains  15   a  and  15   b  can be reduced. 
     Next, the passenger conveyer system according to the fifth embodiment will be described with reference to FIG.  12 . 
     FIG. 12 is a diagram schematically showing a structure of the passenger conveyer system  60  according to the fifth embodiment. Similarly to the passenger conveyer system shown in FIG. 1, the relevant passenger conveyer system is constructed as a distributed driving system in which the driving mechanisms  1   a  to  1   c  are distributed at predetermined intervals along the chain  5 . The structures of the respective distributed driving mechanisms  1   a  to  1   c  are the same as one of the driving mechanism shown in FIG. 3, and thus the description for the structures will be omitted. 
     The different point in the passenger conveyer system  60  according to the fifth embodiment from ones according to the above-described embodiments is that a driving mechanism  62 , which drives turning reverse section for the chains  5  on the upper story, is disposed under the way in and the way out located on the upper story, separately from the distributed driving mechanisms  1   a  to  1   c.    
     The driving mechanism  62  drives the chain  5  in cooperation with the distributed driving mechanisms  1   a  to  1   c . Therefore, the driving mechanism  62  may only generate the driving force sufficient to convey the weight equivalent to the inclination angle element of the summed weight of passengers and loads between the distributed driving mechanism  1   c  located uppermost and the driving mechanism  62  (equivalent to the aforementioned fluctuating load weight). A driving motor  63  of small capacity can cope with the relevant driving force sufficiently. On the other hand, in regard to the driving force necessary for the distributed driving mechanisms  1   a  to  1   c , the following driving forces are sufficient: the driving force sufficient to convey the fluctuating load weight between the turning reverse section for the chain  5  on the lower story and the distributed driving mechanism  1   a  for the distributed driving mechanism  1   a  located lowest; the driving force sufficient to convey the fluctuating load weight between the distributed driving mechanisms  1   a  and  1   b  for the middle distributed driving mechanism  1   a ; and the driving force sufficient to convey the fluctuating load weight between the distributed driving mechanisms  1   b  and  1   c  for the upper distributed driving mechanism  1   c . Accordingly, a driving motor of large capacity is not necessary for the one in each of the distributed driving mechanisms  1   a  to  1   c . Therefore, owing to the cooperation with the inexpensive driving mechanism  62  to a certain extent, on the whole, the production cost for the passenger conveyer system according to the embodiment can be reduced. 
     Next, the passenger conveyer system according to the sixth embodiment of the invention will be described with reference to FIGS. 13,  14 A and  14 B. 
     FIG. 13 is a perspective view showing a main part of a driving mechanism  70  of the passenger conveyer system according to the sixth embodiment. The links  5   b  constituting the chain  5  connect the pin rollers  5   a  sequentially with pitch length P. The structure and the positioning relation of the pin roller rolling gear teeth  11  are the same as ones according to the above-described embodiments. 
     The sixth embodiment is characterized in that a back supporting roller mechanisms including a plurality of back supporting rollers  72 , which rolls the links  5   b  of the chain  5 , is provided at the position over the pin roller rolling gear teeth  11 . The back supporting rollers  72  in the relevant mechanism are arranged in a roller housing  73  of elongated housing shape, whose lower end is open, at predetermined intervals in a longitudinal direction of the chain  5 . In this case, it is desired that the back supporting rollers  72  are arranged such that their intervals δ are set as short as possible in comparison with the pitch length P of the chain  5 , preferably, set equal to or less than P/2. 
     As shown in FIG. 14A, each of the back supporting rollers  72  includes a rotation shaft  74  and a pair of rolling components  75  fixed to the rotation shaft  74 . The rotation shaft  74  of the back supporting roller  72  is supported freely in rotating to the roller housing  73  through bearings  76 . A space between the rolling components  75  is set equivalent to the space between the links  5   b  located on both sides of the pin roller  5   a  in the chain  5 , so that the rolling components  75  can roll without interference with the pin roller  5   a  with the upper edge of the links  5   b  used as rolling surfaces. A rolling surface  75   a , i.e., the outer circumferential surface of the rolling component  75 , which rolls on the link  5   b , is coated with a material such as plastic capable of highly absorbing vibration and noise, rubber or the like. The rolling component  75  is made of damping steel, which has sufficient rigidity and excellent absorptivity of vibration and noise. 
     In regard to the pin roller  5   a  of the chain  5 , as shown in FIG. 14B, to the outer circumferential portion that rolls on the footstep guide rail  4 , there is mounted a cushion ring  77  formed from a material such as ring-shaped soft plastic. The pin roller  5   a  rolls on the footstep guide rail  4  through the cushion ring  77 . In this case, the width of the cushion ring  77  is narrower than the width of the pin roller  5   a . The outer circumferential surfaces of the pin roller  5   a  on both sides of the cushion ring  77  are formed so as to supply a thrust while rolling on the trochoid shaped gear of the pin roller rolling gear teeth  11 . Therefore, the body of pin roller  5   a  employs steel with high rigidity so as not to deform, which is different from the material of the cushion ring  77 . 
     The pin roller rolling gear teeth  11  require the sufficient rigidity in the same manner as the pin roller  5   a . However, the pin roller rolling gear teeth  11  employ damping steel that is sufficiently rigid and further effective in absorbing vibration, so as to absorb vibration and noise which are generated when the pin roller rolling gear supplies thrust to the pin roller  5   a , as much as possible. 
     Next, the action of the driving mechanism  70  in the passenger conveyer system according to the sixth embodiment will be described. 
     In FIG. 13, while rocking, the pin roller rolling gear teeth  11  mesh with the pin rollers  5   a  of the chain  5 , thereby supplying a thrust to the chain  5 . During this process, the back supporting rollers  72  support the chain  5  from the side opposite to the pin roller rolling gears  11  while rolling on the links  5   b  of the chain  5 . More specifically, assume that the force acting on the chain  5  from the pin roller rolling gear teeth  11  is denoted with F. While rolling on the links  5   b  of the chain  5 , the back supporting rollers  72 , which are held in the roller housing  73 , are applied with the vertical drag N that is the element of the force F in a direction perpendicular to the direction which the chain  5  proceeds in. Then the back supporting rollers  72  press the chain  5  to the pin roller rolling gear teeth  11  by the reaction force N′ against the vertical drag N. 
     Therefore, it is possible to prevent a slip from occurring between the meshing pin rollers  5   a  and the gear of the trochoid tooth form in the pin roller rolling gear teeth  11 . As a result, losses of mechanical work can be reduced. In addition to that, it is possible to maintain the mechanical principles in that the pin rollers  5   a  steadily capture the thrust supplied from the pin roller rolling gear teeth  11 , and the pin roller rolling gears having the trochoid shaped gears contribute uniform motion to the pin rollers  5   a.    
     In addition, according to the embodiment, the interval δ in the arrangement of the plural back supporting rollers  72 , which are held in the roller housing  73 , are shorter than the pitch length P of the link  5   b  in the chain  5 . Therefore, moments around the back supporting rollers  72 , which are generated by the vertical drag N, do not increase. Accordingly, the reaction force N′ to support back-up the pin rollers  5   a , which are located at the front and the rear of the back supporting roller  72  does not increase in comparison with the vertical drag N. As a result, there is no need of countermeasure such as strengthening the footstep guide rail  4 . 
     Further, the rolling surface of the rolling component  75  in the back supporting roller  72  is coated with plastic or the like. Therefore, an intermittent impact to be applied to the rolling component  75  by the vertical drag N is absorbed effectively. Furthermore, since the cushion ring  77  is mounted on the pin roller  5   a , an impact transmitted from the footstep guide rail  4  is relieved through the cushion ring  77 , thereby suppressing the generation of vibration and noise. 
     Next, the passenger conveyer system according to the seventh embodiment of the invention will be described with reference to FIGS. 15 and 16. 
     The seventh embodiment is different from the sixth embodiment in the point that the endless circular back supporting means is provided instead of the back supporting rollers  72 . 
     FIG. 15 is a view showing non-end circular back supporting means that back up and support the chain  5  from the side reverse to the pin roller rolling gear teeth  11  in a driving mechanism of the passenger conveyer system  80 . Incidentally, in FIG. 15, the identical constituting components to FIG. 13 are marked with the identical reference symbols, and detailed descriptions will be omitted. 
     The back supporting means includes an elliptical back supporting guide  81  and a back supporting wire rope component  82 , which is connected along the outer circumferential portion of the elliptical back supporting guide  81  in the endless circular form. 
     The back supporting guide  81  is fixed to a supporting member  83 , which is extended from the structure  120 , in the form parallel to the chain  5 . The back supporting wire rope component  82  is formed by contentiously connecting through guide rollers  85  in the endless circular form with a wire rope section  84  being as a unit. The guide rollers  85  are mounted freely in rotation and engage the outer circumferential portion of the back supporting guide  81  with a circumferential groove  86  while rolling. In the back supporting wire rope component  82 , a series of wire rope sections located on the lower side are in contact with the links  5   b  of the chain  5  from the side reverse to the pin roller rolling gear teeth  11 . 
     Therefore, while moving circularly in accordance with the movement of the chain  5 , the back supporting wire rope component  82  supports the chain  5  steadily. That is, the wire rope sections  84  are affected by the vertical drag N as a directional element perpendicular to the traveling direction of the chain  5  out of the force F which the pin rollers  5   a  of the chain  5  is applied from the pin roller rolling gear teeth  11 . Then, the guide rollers  85 , which are held in the wire rope sections  84 , receive the vertical drag N′ while rolling and then press the wire rope sections  84  against the chain  5  with the drag N′. Therefore, it is possible to prevent a slip from occurring between the meshing pin rollers  5   a  and the gear of the trochoid tooth form in the pin roller rolling gear teeth  11 . As a result, losses of mechanical work, which are caused by frictional force or heat generation, can be reduced. 
     Incidentally, it is preferable to use a damping steel product that has sufficient rigidity and absorptivity of vibration and noise for the material of the wire rope section  84  in the back supporting wire rope component  82  in order to relieve an impact caused by the intermittent vertical drag, which is applied from the pin roller rolling gear teeth  11  through the chain  5 . In addition, it is preferable that a portion of the wire rope section  84 , which comes into contact with the link  5   b  of the chain  5 , is coated with thin film made of plastic absorbing vibration and noise, or the like. 
     INDUSTRIAL APPLICABILITY 
     As described above, according to the invention, without using specific constituting components such as a toothed chain or the like, sufficient driving force can be applied in the middle section of a circulating chain with use of an inexpensive and standard chain. Thus it is possible to provide a passenger conveyer system suitable for an escalator of high steps, a moving walkway for long moving distance, or the like.