Conveyors
United States Patent 11 1 Kondo et a1.  
 [ CONVEYORS [75] Inventors: Kyozo Kondo, Mihara; Takeyoshi Okimoto, Takehara, both of Japan [73] Assignee: Mitsubishi Jukogyo Kabushiki Kaisha, Tokyo, Japan [22] Filed: Mar. 28, 1974 [21] Appl. No.: 455,807  
 [30] Foreign Application Priority Data 1111 3,874,297 1 Apr. 1,1975  
 Primary Exan11&#39;nerLloyd L. King Assistant Examiner-D. W. Keen Attorney, Agent, or Firm-Cushman, Darby &amp; Cushman [5 7] ABSTRACT The invention is a variable speed conveyor which comprises a plurality of movable platforms, means to advance the platforms and means to guide the platforms around a circuit composed of a forward path, a revolving zone at one extremity of travel of the conveyor, a return path and a revolving zone at the other extremity of travel of the conveyor, wherein, in operation, the platforms in each revolving zone revolve about an axis substantially perpendicular to the plane in which the platforms move whereby the platforms are available for conveying on both the forward and the return path and wherein the platforms are supported by wheels which run on tracks, the distance between the tracks varying as the speed of the conveyor varies. An endless chain provided with guide rollers for sliding movement along guide channels in the undersides of the platforms is disclosed for driving the platforms through the revolving zone.  
 3 Claims, 13 Drawing Figures as a9 1Q m m a Q -4 PATENTED APR 1 i975 saw 3 u; 7  
 PATENTED APR 7 I975 SHIT t [If 7 coisvrzvoks FIELD OF THE INVENTION This invention relates to variable speed conveyors.  
 BACKGROUND OF THE INVENTION Among the conventional transport systems generally called &#34;moving footway. there is a system constructed by laying horizontally an escalator&#34; and a system of belt-conveyor type on which passengers can ride. However. these prior art systems have disadvantages in that they are of fixed-speed and. in order to assure safety by mitigating the shock when a pedestrian mounts the system. the moving speed of the system was limited to a very low speed.  
  As an improved system free from the aforementioned disadvantages. a variable speed conveyor has been developed. constructed in such manner that respective platforms which are capable of moving along their width-wise direction or along a direction transverse to their widthwise direction. are displaced in their lengthwise direction with respect to each other. the displacement being zero or small in a low speed zone. and large in a high speed zone. In this conveyor system. however. the platforms are adapted to be reversed from their forward path to their return path by revolving about a horizontal axis extending in the widthwise direction of the conveyor system. similar to the prior art systems. Thus only the platforms on their forward path. located on the upper path of the conveyor. are used for transportation. while the platforms on their return path. located on the lower path of the conveyor, cannot contribute to transportation at all. Therefore. the transport efficiency of this conveyor system was low.  
 SUMMARY OF THE INVENTION According to the present invention there is provided a variable speed conveyor which comprises a plurality of movable platforms, means to advance the platforms and means to guide the platforms around a circuit composed of a forward path. a revolving zone at one extremity of travel of the conveyor. a return path and a revolving zone at the other extremity of travel of the conveyor. wherein. in operation. the platforms in each revolving zone revolve about an axis substantially perpendicular to the plane in which the platforms move whereby the platforms are available for conveying on both the forward and the return path and wherein the platforms are supported by wheels which run on tracks. the distance between the tracks varying as the speed of the conveyor varies.  
  The invention includes means for advancing the platforms along the curved track portion which proceeds through the revolving zone. This advancing means includes cable means. endless chain means or the like.  
 movement about a generally horizontal path including a run which underlies the platforms when the platforms are on said curved portion of the track means. said run gradually cutting inwardly more deeply crosswise of said curved portion. then proceeding generally parallel to the curved portion, and then gradually cutting outwardly more deeply crosswise of said curved portion;  
 a plurality ofdrive elements mounted on the endless chain means at equally spaced intervals corresponding locations of the individual ones of said (ill platforms. as the platforms are on said curved portion of the track means:  
 and progressive engagement surface means on each platform. each elongated in a generally horizontal plane widthwise of the respective platform. the respective progressive engagement surface means being arranged to be engaged by the respective drive elements mounted on the endless chain means. whereby the platforms are driven along said curved portion of the track means at least in part by the respective drive elements entering into driving engagement with the respective engagement surface means from outwardly of the respective platforms progressign inwardly and then outwardly therealong and then retreating from driving engagement therewith.  
  In the embodiment illustrated. the drive elements are rollers mounted at equally spaced intervals along the chain means and the progressive engagement surface means on the platforms are guide channel means moving outwardly directed openings for receiving and discharging the roller means.  
  In one form the invention provides a conveyor constructed in such manner that respective platforms which are capable of moving either along their widthwise direction or along a direction transverse of the widtbwise direction. are displaced in their lengthwise direction with respect to each other. the displacement being zero or small in a low speed zone and large in a high speed zone. characterized in that the platforms are revolved about an axis perpendicular to a plane of movement of the platforms rather than being reversed about an axis parallel to the plane of movement of the platforms.  
  It is possible to allow a large number of passengers to successively and safely get on and/or get off the conveyor system in the low speed zone. and also to transport the passengers at a high speed in the high speed zone which occupies the most part of the transport interval.  
  Since the platforms are adapted to be revolved about an axis perpendicular to the plane of movement of the platforms rather than to be reversed by revolving about an axis parallel to the plane of movement of the platforms. not only the forward path of the conveyor but also the return path can be used for transportation of passengers. Consequently the transport capacity efficiency can be enhanced.  
 BRIEF DESCRIPTION OF THE DRAWINGS The invention is further illustrated by reference to the accompanying drawings showing. by way of example. an embodiment of the conveyor in accordance with the invention. in which:  
  FIG. 1 is a schematic plan view showing an outline of a conveyor according to the present invention;  
 FIG. 2 is a plan view of the same embodiment;  
  FIG. 3 is a plan view showing low speed zones and a revolving zone of the same embodiment;  
  FIG. 4 is an enlarged partial plan view showing platforms in a high speed zone and in a low speed zone with overlapped representation for the same embodiment:  
  FIGS. 5 and 6 are transverse and longitudinal crosssection views taken along lines VV and VIVI. respectively. in FIG. 4;  
 FIG. 7 is a side view related to FIG. 6&#39;.  
  FIG. 8 is a view taken along line VII-VII in FIG. 6 as viewed in the direction of arrows;  
  FIG. 9 is an enlarged partial plan view of the portion IX in FIG. 3;  
  HG. I is an enlarged partial side view in the direction of arrow X in FIG. 9:  
  FIG. I I is an enlarged cross-section view taken along line Xl-Xl in FIG. 3&#39;.  
  FIG. I2 is a cross-section view taken along line Xll- Xll in FIG. 4&#39;. and  
  FIG. I3 is a plan view for the portion shown in FIG. 12.  
 DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS Reference numeral I designates a platform formed in a substantially rectangular shape, and at the opposite ends in the lengthwise direction of the platform I are integrally provided additional spaces 2 for mounting handrails. Reference numerals 3 and 4 designate a return path high speed zone and a forward path high speed zone. respectively. To the downstream end of the return path high speed zone 3 an exit low speed zone 6 is connected via a deceleration zone 5. Further downstream of the exit low speed zone 6 an entrance low speed zone 8 is connected via a revolving zone 7. The downstream end of the entrance low speed zone 8 is connected via an acceleration zone 9 to the forward path high speed zone 4. Between the downstream end ofthe forward path high speed zone 4 and the upstream end of the return path high speed zone 3 are also provided a deceleration zone 5. an exit low speed zone 6. a revolving zone 7. an entrance low speed zone 8 and an acceleration zone 9 (not shown in the drawings) which are constructed similarly to those described above. In addition, the entrance low speed zone 8 and the exit low speed zone 6 are provided with amounting station A and a dismounting station 8. respectively.  
  Except in the revolving zone 7. over the entire zones 3. 4. 5. 6, 8 and 9, the platforms I are adapted to be slidably displaceahle in their lengthwise direction with respect to each other. while their opposite side edges directed in their lengthwise direction are maintained in close contact to each other, as will be fully described later and as shown in FIG. I2.  
  As shown in FIG. 2. an outer track 10 and an inner track I I are disposed on a floor extending in the direction in which it is intended to move the platforms. Wheels I2 and I3 which can roll within the outer track III and inner track I] are pivot-ably mounted on the lower surface of the platform I as shown in detail in FIG. 5.  
  As will be apparent from FIGS. I and 2, the distance between the outer track III and the inner track II is wide in the low speed zones 6 and 8, is narrow in the high speed zones 3 and 4 and is continuously varied in the acceleration and deceleration zones 9 and 5, respectively. Consequently in the low speed zones 6 and 8. when the platforms I are driven along their widthwise direction the aforementioned displacement in the lengthwise direction is zero. In the high speed zones 3 and 4. when the platforms I are driven along a direc tion transverse of the widthwise direction the afore mentioned displacement in the lengthwise direction is a maximum. In the acceleration and deceleration zones 9 and 5. respectively, the direction of movement ofthe platforms with respect to their widthwise direction is continuously varied while the aforementioned displace ment in the lengthwise direction also continuously varies.  
  As shown in FIG. 3. outside the low speed zones 6 and 8. a low speed zone outside driving chain 14 extends around a chain driving sprocket I5. Meshing pawls 16 are fixedly secured to the driving chain 14 at a pitch equal to the pitch of the platforms 1. so that pins 17 mounted on the platforms I and projecting therefrom engage the meshing pawls I6.  
  In addition. as partly shown in FIG. 3 inside the low speed zones 6 and 8 there is a low speed zone inside driving chain I8 which extends around a large chain driving sprocket 20 which rotates about its shaft I9. Meshing pawls 2I are also fixedly secured to the driving chain I8 at a pitch equal to the pitch of the platforms. so that pins 22 projecting from the platforms engage the meshing pawls 21.  
  Since the low speed zone outside and inside driving chains I4 and I8 are adapted to be driven by the sprockets I5 and 20, respectively, at the same fixed speed. within the low speed zones 6 and 8 the platforms I are conveyed at a fixed speed and a mutually equal pitch is maintained while the platforms 1 are perpendicular to the direction of movement.  
  Inside the revolving zone 7, a guide member 23 is provided along an outer circumference of the chain driving large sprocket 20. while outside the revolving zone 7. a semi-circular guide member 24 is provided extending to the outer end edges of the platforms 1 in the low speed zones 6 and 8.  
  Further in the revolving zone 7, a chain 25 extends around a fixed-speed driving sprocket 26 and sprockets 27. On the chain 25 are mounted a plurality of rollers 28 at equal intervals. Guide channels 29 {sec FIGS. 9 and [0) are provided on the lower surfaces of the platforms I with the rollers 28.  
  The speed of the chain 25 is preselected relatively high so that the speed component of the chain 25 along the direction of movement of the platforms I in the low speed zone 6 at the point where the roller 28 begins to engage with the guide channel 29 may be equal to the speed of movement ofthe platforms I in the low speed zone 6. The interval between the rollers 28 is preselected so that in the middle portion of the revolving zone 7. the lengthwise directions of the platforms I is directed towards the shaft 19 of the large sprocket 20. Therefore. the platforms I in the exit low speed zone 6 can be smoothly passed into the revolving zone 7, where the outside end of each platform is accelerated until it reaches the middle portion and then it is decelerated. Thus. the platforms I are adapted to be revolved by I about the shaft I9 of the large sprocket 20 and guided by the guide members 23 and 24.  
  Explaining now the details of the platforms I as illustrated in FIG. 4. reference numeral 30 designates a step board of the platform I. and two parallel lines C-C represent the opposite side edges of the conveyor consisting of an array of platforms I in the high speed zones 3 and 4. In addition, in the same Figure is shown a chain line DD which represents the direction of movement of the platforms I in the low speed zones 6 and 8. It is to be noted that FIG. 4 shows the track and wheel arrangements both in the high speed zone and in the low speed zone overlapped in the same Figure.  
  More particularly. in the high speed zones 3 and 4 a pair of outer tracks 10:- for high speed zones and a pair of inner tracks I It for high speed zones are laid parallel to the opposite side edges C-C of the conveyor (only the right side ones of the pairs being shown in the Figure). In the low speed zones 6 and 8 a pair of outer tracks IOu&#39; for low speed zones and a pair of inner tracks lid for low speed zones are laid parallel to the direction of movement DD of the platforms I. that is. the widthwise direction of the platforms (only the left side ones of the pairs being shown in the Figure). In the high speed zone and in the low speed zone. respectively. the outer track pair 101&#39; or HM and the inner track pair Ilc or IId are engaged with wheels on the opposite. sides 12c. 12d and I3(&#39;. I3u&#39;.  
  In addition, on the handrail mounting spaces 2 of the platform I are mounted handrails 3I which are bent in a L-shape, and the handrails of the platforms I adjacent to the platform I depicted by a solid line in the high speed zones 3 and 4. are depiced by a double-dot chain line and given the reference numeral 3h.  
  Still further. as shown in FIGS. 4 and 6. in the high speed zones 3 and 4 is provided a chain 32 along a line EE (in FIG. 4) parallel to the outer and inner tracks c and [01]. Two protrusions 33 to engage the chain 32 are mounted on the lower surface of the platform I. Assuming that the distance between the two protrusions 33 is represented by l. the distance from a cross point F where the chain 32 intersects with the longer edge ofthe platform I to the nearest one of said protrusions 33 is preselected to be equal to V2, and therefore. the distance between the protrusions 33 on the same platform I is equal to the distance between the adjacent protrusions 33 on the adjoining platforms I.  
  As shown in FIG. 5. each of the wheel assemblies I and I31 to engage the outer and inner tracks Illc and l lr&#39;. respectively. in the high speed zones 3 and 4. consists of a support member 34. a rotary shaft 36 rotatably fitted in a bearing bush of the platform I. a thrust ball bearing 37 for allowing the rotary shaft 36 to rotate lightly. an inner race 38 fitted to the support member 34. balls 3) arranged around the outer circumference of the inner race 38. an outer race 40 fitted around the outer periphery ofthe balls 39. and an outer ring of rubber 4| fitted around the outer circumference of the outer race 40.  
  As shown in FIGS. 6 and 8. on a mutual coupling shaft 42 of a chain 32 is rotatably supported a roller 43. and lock pieces 45 adapted to grasp a tip end outer buffer piece 44 of the protrusion 33 are integrally mounted on the chain 32 with rivets 46. A sprocket 47 for driving the chain 32 is provided with notches 48 and shown in FIG. 7 so that the sprocket 47 will not make contact with said protrusion 33 and lock pieces 45.  
 The details of the portion of the platform I which makes contact with the guide member 23 or 24 in the revolving zone 7. are shown in FIG. I I. The pin I7 provided at the opposite ends of the platform I. is rotatably fitted via a bearing bush 50 around a shaft 49 projecting downwardly from the platform I. and prevented from falling down by means of a cap 51. Above the pin I7 is rotatably fitted a guide roller 54 via a bearing bush 53 separated from the pin I7 by means of a spacer S2. The guide roller 54 is adapted to roll along said guide member 23 or 24 in close contact therewith. Reference numeral 55 designates the centre of the low speed zone outside and inside driving chains 18 and 14, respectivelv.  
  A transverse cross-section of the platforms I is shown in FIG. 12. Along one side edge of the platform l is keyed a slide piece 56 of substantially cylindrical shape which is integrally secured to the platform I by means of bolts 58. On the top of the slide piece 56 are provided comb-like ridges 59 directed laterally (parallel to the plane ofthe paper in FIG. I2). Except for in the revolving zone 7. over the entire zones 3. 4. S. 6. 8 and 9 the slide piece 56 can relatively slide along the opposite side edge in the lengthwise direction of the adjoining platform I while keeping tight contact with the opposite side edge. and also the platforms I can tilt relative to each other about the centre axis (directed at a right angle to the plane of the paper in FIG. l2) of the slide piece 56.  
  In addition. on the step board 30 of the platform I are provided strip-like ridges 60 directed in the widthwise direction of the platform I (see FIG. [3). and scrapers 61 disposed in the exit or entrance low speed zone 6 or 8 are adapted to properly and loosely lit in the grooves between the ridges 59 and 60. On the lower surface of the platform I are provided bores 62 for mounting the bolts 58.  
  Since the illustrated embodiments is constructed as described above. when the driving sprocket 47 (see FIG. 7) in the high speed zones 3 and 4. the driving sprockets [5 (see FIG. 3) in the low speed zones 6 and 8. and the driving sprockets 20 and 26 (see FIG. 3) in the revolving zone 7 are rotated. the chains 32. I4. I8 and 25 are driven simultaneously.  
  As shown in FIG. 4. in the high speed zones 3 and 4, during a period in which the platform I moves up to the position where the adjacent platform I was initially located. the platform I moves along the outer and inner tracks Hit and lit for a distance about twice as long as the width of the platform I. because the platforms I are tilted by about 30 with respect to the outer track Illc and the inner track He, and thus the passengers are conveyed at a speed about twice as high as the moving speed in the low speed zones 6 and 8.  
  In the deceleration zone 5 or the acceleration zone 9. the platforms I are subjected to a pressing force from the platforms I in the backward path high speed zone 3 or the entrance low speed zone 8 on the upstream side which are driven by the chains 32. I4 and I8. and also they are subjected to restriction by the outer and inner tracks 10 and I I. so that the platforms I in the deceleration or acceleration zone 5 or 9 are moved while being decelerated or accelerated and varying the relative displacement in the lengthwise direction as shown in FIG. 2.  
  In the exit low speed zone 6 and the entrance high speed zone 8. the platforms I are moved at a low speed along their widthwise direction while their relative displacement in the lengthwise direction is maintained at zero.  
  In the revolving zone 7. the interval between the outer ends of the adjacent platforms 1 is progressively widened and after passing the middle portion it is progressively narrowed by the action of the rollers 28 on the chain 25 which are engaged with the guide channels 29 on the lower surfaces of the platforms I. while the interval between the inner ends of the adjacent platforms I is kept constant by the meshing pawls 21 of the low speed zone inside driving chain 18. and thus the platforms I are revolved by l along a semicircle having its centre at the shaft 19 while their inner and outer ends are guided by the guide members 23 and 24. respectively.  
  As described. since the platforms I are revolved along a horizontal plane about a vertical axis in the revolving zone 7. not only the forward path but also the backward path can be used for transporation of passengers. so that the transport capacity is doubled in comparison to the prior art conveyor in which only the forward path can be used, and thus the transport efficiency is widely enhanced.  
  In addition. in the high speed zones 3 and 4. the low speed zones 6 and 8. and the revolving zone 7. since the interval between the adjacent platforms 1 is restricted by the meshing with the chains 32. l4. l8 and 25. the slide piece 56 along one side edge of the platform 1 and the opposite side edge of the adjacent platform I can slide relative to each other while being kept in tight contact with each other without a gap or space appearing therebetween and without causing disengagement therebctween.  
  Furthermore, since the adjoining platforms I can be tilted relative to each other about the centre axis of the slide piece 56. the conveyor can be tilted relative to the horizontal plane without requiring any specific coupling means.  
  While the present invention has been described above with reference to a preferered ambodiment, it is intended that the present invention should not be limited to the illustrated embodiment but various changes in design could be made without departing from the scope of the invention.  
 We claim:  
  l. A variable speed conveyor which comprises a plurality of movable platforms, means to advance the platforms and means to guide the platforms around a cir&#39; cuit composed of a forward path, a revolving zone at one extremity of travel of the conveyor. a return path and a revolving zone at the other extremity of travel of the conveyor. wherein. in operation the platforms in each revolving zone revolve about an axis substantially perpendicular to the plane in which the platforms move whereby the platforms are available for conveying on both the forward and the return path and wherein there is provided in each revolving zone means to engage the outermost end of each platform and advance the platform through the revolving zone.  
 comprising a cable on which rollers are situated at equally spaced intervals and wherein the platforms are provided with slots which are engaged by the rollers in the revolving zone.  
  2. In a variable speed conveyor which includes a plu rality of platforms rollingly mounted in a series upon a circuit of generally horizontal track means which includes at least one portion which is curved in a generally horizontal plane and means for advancing the platforms along the track means.  
 the improvement wherein:  
 the advancing means includes means for advancing the platforms through said curved portion. comprising: endless chain means mounted on sprocket means for movement about a generally horizontal path including a run which underlies the platforms when the platforms are on said curved portion of the track means. said run gradually cutting inwardly more deeply crosswise of said curved portion, then proceeding generally parallel to the curved portion. and then gradually cutting outwardly more deeply crosswise of said curved portion; a plurality of drive elements mounted on the endless chain means at equally spaced intervals corresponding to locations of the individual ones of said platforms. as the platforms are on said curved portion of the track means; and progressive engagement surface means on each platform each elongated in a generally horizontal plane widthwise of the respective platform. the respective progressive engagement surface means being arranged to be engaged by the respective drive elements mounted on the endless chain means. whereby the platforms are driven along said curved portion of the track means at least in part by the respective drive elements entering into driving engagement with the respective progressive engagement surface means from outwardly of the respective platforms progressing inwardly and then outwardly therealong and then retreating from driving engagement therewith.  
  3. The variable speed conveyor improvement of claim 2. wherein the drive elements on the endless chain means are constituted by rollers and wherein the progressive engagement surface means on each platform is constituted by guide channel means thereon. having an outwardly directed opening for receiving and discharging the respective roller means.