Abstract:
A conveying apparatus formed so as to selectively move a to-be-conveyed object support table ( 3 ) installed on a conveying traveler body ( 1 ) to a lifted position by pushing up the support table by cam rails ( 40 ) laid down in the specific section of a conveying route, wherein the holding function of the to-be-conveyed object support table ( 3 ) at the lifted position is increased to enhance safety. A to-be-latched portion ( 33 ) reciprocatingly moving in a roughly horizontal direction according to a standing/falling motion of the crosslink mechanisms ( 12 ) and latches ( 34 ) for locking automatically engaged with the to-be-latched portion ( 33 ) when the to-be-conveyed object support table ( 3 ) is lifted to a predetermined position are installed on the conveying traveler body ( 1 ) sides of the crosslink mechanisms ( 12 ) liftably supporting the to-be-conveyed object support table ( 3 ). Unlocking cams ( 41 ) switching the latches ( 34 ) for locking to a lock release attitude according to the traveling of the conveying traveler body ( 1 ) are installed on the cam rails at an end portion of the specific section.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a conveying apparatus formed so as to selectively move a to-be-conveyed object support table provided so as to be liftable and lowerable on a conveying traveler body such as a carriage to a lifted position by a cam rail provided on the side of a conveying route. 
   DESCRIPTION OF THE PRIOR ART 
   For this type of conveying apparatus, as described in Patent Literature 1, a to-be-conveyed object support table is supported on a conveying traveler body so as to be freely liftable and lowerable via a freely erectable crosslink mechanism, and in a specific section of a conveying route, cam rails that selectively move the to-be-conveyed object support table to a lifted position by working on a to-be-operated portion provided in the crosslink mechanism so as to raise the crosslink mechanism are disposed. 
   Patent Literature 1: Japanese Published Unexamined Patent Application No. H07-172538 
   Therefore, conventionally, according to the configuration of this type of conveying apparatus, if the to-be-operated portion provided in the crosslink mechanism is composed of a lifting/lowering rod to thrust up the crosslink as described in, for example, Patent Literature 1, when an accident such that the to-be-operated portion (lifting/lowering rod) is broken owing to a material deterioration of the to-be-operated portion (lifting/lowering rod) or overloading of a to-be-conveyed object occurs, the to-be-conveyed object support table that has been held at the lifted position by the to-be-operated portion (lifting/lowering rod) and cam rails falls down to a lowering limit position by gravity with impact, and this may lead to a fatal accident resulting in injury or death. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a conveying apparatus that can eliminate conventional problems as described above, and means therefore will be shown with reference numerals in embodiments to be described later denoted in parentheses. In a conveying apparatus in which a to-be-conveyed object support table ( 3 ) is supported on a conveying traveler body ( 1 ) so as to be freely liftable and lowerable via a freely erectable crosslink mechanism ( 12 ), and a cam rail ( 40 ) that selectively moves the to-be-conveyed object support table ( 3 ) to a lifted position by working on a to-be-operated portion ( 14 ) provided in the crosslink mechanism ( 12 ) so as to raise the crosslink mechanism ( 12 ) is disposed in a specific section of a conveying route, on a side of the conveying traveler body ( 1 ) of the crosslink mechanism ( 12 ), a to-be-latched portion ( 33 ) that reciprocatingly moves in a roughly horizontal direction as a result of a standing/falling motion of the crosslink mechanism ( 12 ) is provided, a locking latch ( 34 ) that is automatically latched with the to-be-latched portion ( 33 ) when the to-be-conveyed object support table ( 3 ) has been lifted to a predetermined position is provided, and, at an end portion of the specific section, an unlocking cam ( 41 ) that switches the locking latch ( 34 ) to an unlocking posture as a result of traveling of the conveying traveler body ( 1 ) is provided. 
   With regard to carrying out the present invention with the above-described configuration, concretely, as in a second aspect of the invention, when the crosslink mechanism ( 12 ) includes two crosslinks ( 13   a  and  13   b ) provided side by side and being in conjunction with each other, the to-be-latched portion ( 33 ) can be composed of a slide fulcrum shaft ( 25 ) on the conveying traveler body ( 1 ) side hung between the two crosslinks ( 13   a  and  13   b ). 
   In addition, as in a third aspect of the invention, when a plurality of specific sections that are different in height of lifted positions of the to-be-conveyed object support table ( 3 ) are provided, and in the locking latch ( 34 ), a plurality of latching portions ( 34   b  and  34   c ) can be provided in a manner corresponding to the lifted positions of the to-be-conveyed object support table ( 3 ) in the respective specific sections. The configuration according to the third aspect of the invention can be carried out in combination with the configuration according to either the first or second aspect of the invention. 
   Although the to-be-operated portion ( 14 ) provided in the crosslink mechanism ( 12 ) may be of any configuration, however, particularly, as in a fourth aspect of the invention, when the links ( 15   a  and  15   b ) of the crosslink mechanism ( 12 ) are disposed in a direction parallel to a traveling direction of the conveying traveler body ( 1 ), of the links ( 15   a  and  15   b ), on the link ( 15   a ) provided with a position fixing fulcrum shaft ( 19 ) on the conveying traveler body ( 1 ) side, a cam follower roller ( 31 ) can be supported about an axis so as to protrude to a downside of the conveying traveler body ( 1 ) at a position close to the position fixing fulcrum shaft ( 19 ), and the to-be-operated portion ( 14 ) can be composed of the cam follower roller ( 31 ). The configuration according to the fourth aspect of the invention can be carried out in combination with the configuration according to any one of the first to third aspects of the invention. 
   Moreover, when the configuration according to the fourth aspect of the invention is employed and, as in a fifth aspect of the invention, when the crosslink mechanism ( 12 ) includes a pair of right and left crosslinks ( 13   a  and  13   b ) being in conjunction with each other, of the links ( 15   a  and  15   b ) provided two each to compose both these links ( 13   a  and  13   b ), the links ( 15   a ) provided with position fixing fulcrum shafts ( 19 ) on the conveying traveler body ( 1 ) side can be coupled to each other by a coupling member ( 28 ) at a position close to the position fixing fulcrum shafts ( 19 ), and the cam follower roller ( 31 ) can be supported about an axis below the coupling member ( 28 ). 
   Furthermore, when the configuration according to the fourth and fifth aspects of the invention is employed, as in a sixth aspect of the invention, it is desirable that the links ( 15   a  and  15   b ) of the crosslink mechanism ( 12 ) are disposed in a direction where position fixing fulcrum shafts ( 19  and  24 ) at one end are located forward in the traveling direction of the conveying traveler body ( 1 ) relative to slide fulcrum shafts ( 20  and  25 ) at the other end. 
   By a conveying apparatus according to the present invention with the above-described configuration, even when a situation such that the to-be-operated portion on the crosslink mechanism side is broken occurs, the locking latches that have been automatically latched with the to-be-latched portions on the crosslink mechanism side prevents a falling motion of the crosslink mechanism, that is, a lowering motion of the to-be-conveyed object support table, so that a fatal accident caused by the to-be-conveyed object support table falling down with impact can be avoided, and safety can be improved. Moreover, an actuator that requires a special operation or power supply for locking the crosslink mechanism in a standing condition at the start portion of a specific section (locking the to-be-conveyed object support table at a lifted position) and unlocking the locked condition at the end portion of the specific section is unnecessary, so that the invention can be easily carried out without involving an inconvenience to lower workability or a substantial rise in cost. 
   The to-be-latched portions can also be provided in the crosslinks at positions close to the slide fulcrum shaft on the conveying traveler body side. In this case, however, the to-be-latched portions also slightly move up and down as a result of a standing/falling motion of the crosslink mechanism. Accordingly, it is desirable to provide the to-be-latched portions concentrically with a slide fulcrum on the conveying traveler body side of the crosslink mechanism, however, particularly, when the crosslink mechanism includes two crosslinks provided side by side and being in conjunction with each other, according to the second aspect of the invention, the slide fulcrum shaft on the conveying traveler body side hung between the two crosslinks can be used also as the to-be-latched portions, so that the invention can be carried out at a low cost with a simplified structure. Moreover, since the slide fulcrum shaft does not involve an up-and-down motion, an automatic latching motion of the locking latches can also be reliably carried out. 
   Moreover, by the configuration according to the third aspect of the invention, the to-be-conveyed object support table can be locked at a plurality of lifted positions different in height by using one locking latch, so that the invention can be carried out at a lower cost with a more simple structure than when a plurality of locking latches and unlocking cams corresponding to the respective locking latches are provided in a manner corresponding to the respective lifted positions. 
   Furthermore, by the configuration according to the fourth aspect of the invention, the to-be-operated portion working on the cam rail on the conveying route side is composed of the cam follower roller supported about an axis on the links of the crosslink mechanism, and via the cam follower roller, the links of the crosslink mechanism are directly pushed up by the cam rail so as to carry out a standing motion. Therefore, even when the slope of a to-be-operated portion (cam follower roller) pushing-up action portion of the cam rail is increased so as to reduce a traveling distance of the conveying traveler body required for pushing up the to-be-conveyed object support table to the lifted position, the crosslink mechanism can be made to carry out a standing motion more smoothly with less difficulty than when a conventional lifting/lowering rod is vertically pushed up. In other words, the slope of the to-be-operated portion pushing-up action portion of the cam rail can be increased to improve use efficiency of the conveying route. In addition, since there is no such lifting/lowering rod, as in the conventional art, that is likely to be broken by buckling, the invention can also be easily carried out as a conveying apparatus that handles a major load. As a matter of course, in the structure, the lifting/lowering rod, the lifting/lowering guide means thereof, the mechanism that converts a lifting motion of the lifting/lowering rod to a swinging motion of the links of the crosslink mechanism, and the like are no longer necessary, so that the invention can be carried out at a low cost with a smaller number of components. 
   When the crosslink mechanism includes a pair of right and left crosslinks being in conjunction with each other, by the configuration according to the fifth aspect of the invention, in comparison with when cam follower rollers are provided for the pair of right and left crosslinks, respectively, only one cam follower roller and one cam rail are necessary, so that the invention can be carried out at a low cost with a simple structure, and both crosslinks can be made to carry out a standing/falling motion in a manner reliably synchronized by the cam rail on the conveying route side. 
   In addition, by the configuration according to the sixth aspect of the invention, when the links of the crosslink mechanism are disposed in a direction where position fixing fulcrum shafts at one end are located rearward in the traveling direction of the conveying traveler body relative to slide fulcrum shafts at the other end, the to-be-operated portion (cam follower roller) by the cam rail can be made closer to the position fixing fulcrum shafts of the links. In other words, the to-be-operated portion (cam follower roller) by the cam rail can be arranged close to the position fixing fulcrum shafts of the links to increase the height of the lifted position of the to-be-conveyed object support table while reducing the pushing-up amount (cam rail height) of the to-be-operated portion (cam follower roller) by the cam rail, so that the conveying traveler body can be provided as a low-floor structure. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a partially longitudinally sectional schematic side view exemplifying a basic configuration of a carriage-type conveying apparatus; 
       FIG. 1B  is a schematic plan view of the same; 
       FIG. 2  is a longitudinally sectional side view showing a crosslink mechanism with a locking means according to the present invention; 
       FIG. 3  is a longitudinally sectional rear view showing the same crosslink mechanism made to stand up by a cam rail; 
       FIG. 4  is a cross-sectional plan view of the same crosslink mechanism in a fallen condition; 
       FIG. 5  is a longitudinal sectional side view showing the same crosslink mechanism made to stand up by a cam rail; 
       FIG. 6  is a longitudinal sectional side view showing the locking mechanism of the same crosslink mechanism being unlocked; 
       FIG. 7  is a longitudinal sectional rear view showing a crosslink mechanism made to stand up by a cam rail, which is a second embodiment of the present invention; and 
       FIG. 8  is a longitudinal sectional side view showing the locking means of the crosslink mechanism being unlocked in the same second embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Hereinafter, detailed embodiments of the present invention will be described based on the accompanying drawings.  FIG. 1  exemplify a basic configuration of a friction-drive carriage type conveying apparatus with a freely liftable and lowerable to-be-conveyed object support table. Reference numeral  1  denotes a conveying traveler body that is long in a traveling direction and is rectangular in a plane, which is equipped with two front and rear sets of right and left pairs of wheel units  2   a  to  2   d  and a freely liftable and lowerable to-be-conveyed object support table  3 . The respective wheel units  2   a  and  2   d  have wheels  5  that roll on a pair of right and left guide rails  4   a  and  4   b  laid down along a conveying route, and in the two front and rear wheel units  2   a  and  2   c  on one of the right and left sides (in the illustrated example, left side), anti-vibration vertical axis rollers  6  that sandwich the guide rail  4   a  from both right and left sides are provided. The conveying traveler body  1  is propelled by a friction drive means  7  concurrently provided at an appropriate point of the conveying route. The friction drive means  7  is conventionally well known and composed of a drive friction wheel  9  that abuts against one friction surface  8   a  of a pair of right and left mutually parallel vertical friction surfaces  8   a  and  8   b  formed on the conveying traveler body  1  so as to continue across the overall length thereof, a motor  10  for rotary drive of the drive friction wheel  9 , and a backup roller  11  that abuts against the other friction surface  8   b  so as to sandwich the conveying traveler body  1  between the same and drive friction wheel  9 . 
   Although the friction drive means  7  has been exemplified as a means for propelling the conveying traveler body  1 , a propelling means by any other method may be employed, such as driving at least one of the wheels  5  by a motor, or engaging a drive chain provided in a tensioned state so as to move along the conveying route of the conveying traveler body  1  with the conveying traveler body  1  and propelling the conveying traveler body  1  by the drive chain. In addition, for the vertical friction surfaces  8   a  and  8   b  that are necessary in the conveying traveler body  1  when the friction drive means  7  is used, both right and left side surfaces may be diverted as they are or other members may be attached. Furthermore, although individually independent carriages have been used as the conveying traveler bodies  1 , the conveying device may be one in which to-be-conveyed object support tables  3  are disposed at appropriate intervals on a conveying object traveler body that continues in the conveying route direction, as in a slat conveyer. 
   The to-be-conveyed object support table  3  is supported so as to be vertically liftable and lowerable by a crosslink mechanism  12  interposed, under the to-be-conveyed object support table  3 , between the same and conveying traveler body  1 . This crosslink mechanism  12  includes a pair of right and left crosslinks  13   a  and  13   b  and a to-be-operated portion  14 . In a specific section of the conveying route of the conveying traveler body  1 , that is, a specific section where the to-be-conveyed object support table  3  is kept lifted at a lifted position, a cam rail  40  that works on the to-be-operated portion  14  of the crosslink mechanism  12  so as to make the crosslink mechanism  12  stand up and thereby raises the to-be-conveyed object support table  3  to a lifted position is laid down. 
     FIG. 2  to  FIG. 4  show an embodiment of the crosslink mechanism  12  configured based on the present invention. The pair of right and left crosslinks  13   a  and  13   b  included in the crosslink mechanism  12  are formed of two pairs of links  15   a  and  15   b  whose center crossover portions are pivotally mounted at both end portions of a common center fulcrum shaft  16  in the right and left horizontal direction, and of the links  15   a  and  15   b  provided two each, front end portions of both links  15   a  to be located inside are pivotally mounted so as to be freely swingable up and down by mutually concentric position fixing fulcrum shafts  19  in the right and left horizontal direction on a pair of right and left bearing members  18  provided at both right and left sides of the upside of a front end portion of a plane-rectangular frame  17  on the conveying traveler body  1  side. Rear end portions of both links  15   a  are coupled by a common slide fulcrum shaft  20  in the right and left horizontal direction, and rollers  21  removably supported on both ends of the common slide fulcrum shaft  20  are fitted with back-and-forth slide guides  22  provided at both right and left sides of the downside of a rear end portion of the to-be-conveyed object support table  3  so as to be rollable in the back and forth direction. Of the links  15   a  and  15   b  provided two each, front end portions of both links  15   b  to be located outside are pivotally mounted so as to be freely swingable up and down by mutually concentric position fixing fulcrum shafts  24  in the right and left horizontal direction on a pair of right and left bearing members  23  provided at both right and left sides of the downside of a front end portion of the to-be-conveyed object support table  3 . Rear end portions of both links  15   b  are coupled by a common slide fulcrum shaft  25  in the right and left horizontal direction, and rollers  26  removably supported on both ends of the common slide fulcrum shaft  25  are fitted with back-and-forth slide guides  27  provided at both right and left sides of the upside of a rear end portion of the plane-rectangular frame  17  so as to be rollable in the back and forth direction. 
   The to-be-operated portion  14  of the crosslink mechanism  12  shown in  FIG. 2  and  FIG. 4  is composed of a cam follower roller  31  removably supported via a bearing member  29  and a spindle  30  in the right and left horizontal direction below a center portion of a coupling member  28  in the right and left horizontal direction that couples and integrates, of links  15   a  and  15   b  provided two each to compose the pair of right and left crosslinks  13   a  and  13   b , both links  15   a  with each other at a position in the vicinity of the front end portions of both links  15   a  to be inside. The cam follower roller  31  is protruded downward further than the bottom surface of the conveying traveler body  1  when the to-be-conveyed object support table  3  is located at a lowering limit position as shown in  FIG. 2 . 
   Moreover, in the crosslink mechanism  12 , a locking means  32  that locks the to-be-conveyed object support table  3  at a lifted position is concurrently provided. The locking means  32  includes a pair of right and left latches  34  that use, as to-be-latched portions  33 , the common slide fulcrum shaft  25  hung between the rear end portions of both links  15   b  to be outside of the links  15   a  and  15   b  provided two each to compose the pair of right and left crosslinks  13   a  and  13   b  and are automatically latched with the to-be-latched portions  33 . The respective latches  34  are, as shown in  FIG. 3  and  FIG. 4 , arranged with respect to the cam follower roller  31  of the to-be-operated portion  14  in a condition separated to the right and left, are supported about an axis so as to be freely swingable up and down by mutually concentric spindles  36  in the right and left horizontal direction on two right and left sets of bearing members  35  disposed by use of a reinforcement  17   a  hung in the right and left horizontal direction at a middle position in the back-and-forth direction of the plane-rectangular frame  17  of the conveying traveler  1  side, and are held by gravity at home positions where abutting members  37  provided as annexes to the respective latches  34  are caught by the bearing members  35 . Moreover, in the respective latch  34 , arm portions  34   a  are integrally provided downward in connected row arrangements, and on the lower ends of the arm portions  34   a , cam follower rollers  39  are removably supported via mutually concentric spindles  38  in the right and left horizontal direction. The cam follower rollers  39  are protruded downward further than the bottom surface of the conveying traveler body  1 . 
   The to-be-conveyed object support table  3  is normally stable in a condition lowered to a lowering limit position shown in  FIG. 2 . At this time, the lowering limit position of the to-be-conveyed object support table  3  is determined by a height-adjustable support tool (which is conventionally well known, and illustration is omitted) provided in a standing condition on the conveying traveler body  1  side. When the to-be-conveyed object support table  3  is located at a lowering limit position as such, the pair of right and left crosslinks  13   a  and  13   b  of the crosslink mechanism  12  are in a fallen condition as shown in  FIG. 2 , and the cam follower roller  31  of the to-be-operated portion  14  is protruded from the bottom surface of the conveying traveler body  1  at the maximum. 
   Therefore, when the traveling conveying traveler body  1  enters a specific section where the to-be-conveyed object support table  3  is kept lifted at a lifted position, the cam follower roller  31  of the to-be-operated portion  14  gradually rides on the cam rail  40  as shown in  FIG. 5 , and the cam rail  40  thrusts up the inside links  15   a  of the pair of right and left crosslinks  13   a  and  13   b  via the cam follower roller  31  of the to-be-operated portion  14  and coupling member  28 . Accordingly, the pair of right and left crosslinks  13   a  and  13   b  carry out a standing motion in conjunction with each other, so that the to-be-conveyed object support table  3  supported by the pair of right and left crosslinks  13   a  and  13   b  rises while maintaining a horizontal posture. At this time, the upper and lower common slide fulcrum shafts  20  and  25  of the pair of right and left crosslinks  13   a  and  13   b  are to slide horizontally forward via the rollers  21  and  26  and the slide guides  22  and  27 , however, the lower common slide fulcrum shaft  25  (to-be-latched portions  33 ) passes while pushing up the pair of right and left latches  34  via inclined surfaces on the downside of the front ends thereof immediately before the to-be-conveyed object support table  3  reaches the lifted position, and when the to-be-conveyed object support table  3  has reached the lifted position, that is, when the cam follower roller  31  of the to-be-operated portion  14  has reached a highest flat surface of the cam rail  40 , concave latching portions  34   b  of the pair of right and left latches  34  are fitted and latched with the lower common slide fulcrum shaft  25  (to-be-latched portions  33 ) from upside by gravity. As a matter of course, springs that forcedly charge the respective latches  34  downward may be used together. 
   As described above, when the conveying traveler body  1  enters a specific section, the conveying object support table  3  that has been located at a lowering limit position is lifted to the lifted position by the operation of the cam rail  40  and crosslink mechanism  12 . At this time, the latches  34  of the locking means  32  are automatically latched with the to-be-latched portions  33  (lower common slide fulcrum shaft  25 ) of the crosslink mechanism  12  so as to prevent the pair of right and left crosslinks  13   a  and  13   b  in a standing condition from carrying out a falling motion. Namely, the concave latching portions  34   b  of both latches  34  fitted with the common slide fulcrum shaft  25  (to-be-latched portions  33 ) prevents a rearward slide of the common slide fulcrum shaft  25  (to-be-latched portions  33 ) of the crosslinks  13   a  a and  13   b  in a standing condition when the to-be-conveyed object support table  3  is lowered from the lifted position. Therefore, even if the to-be-operated portion  14  (cam follower roller  31 ) that has been pushed up by the cam rail  40  is broken for some reason during the time the conveying traveler body  1  is traveling in the specific section where the to-be-conveyed object support table  3  is kept lifted at the lifted position and the thrusting effect of the cam rail  40  against the crosslinks  13   a  and  13   b  is consequently lost, in other words, even if there is no cam rail  40  between a start portion and an end portion of the specific section, the to-be-conveyed object support table  3  can be reliably held at the lifted position. 
   At the end portion of the specific section where the to-be-conveyed object support table  3  is kept lifted at the lifted position, unlocking cams  41  are laid on the conveying route side of the conveying traveler body  1  as shown in  FIG. 6 . The unlocking cams  41  are arranged on both right and left sides of the cam rail  40  in a manner corresponding to the respective latches  34  so that the cam follower rollers  39  of the latches  34  ride thereon as the conveying traveler  1  travels, and the length and position are set so that the cam follower rollers  39  ride on the unlocking cams  41  so as to swing the latches  34  upward against gravity, the concave latching portions  34   b  of the latches  34  are separated upward from the common slide fulcrum shaft  25  (to-be-latched portions  33 ) on the crosslink mechanism  12  side, and then the cam follower roller  31  being the to-be-operated portion  14  of the crosslink mechanism  12  descends down an end downhill slope portion of the cam rail  40 , the crosslinks  13   a  and  13   b  carry out a falling motion, and the common slide fulcrum shaft  25  (to-be-latched portions  33 ) leaves rearward from the position directly below the concave latching portions  34   b  of the latches  34 . Therefore, at the end portion of the specific position, after the locking effect of the locking means  32  at the lifted position of the to-be-conveyed object support table  3  is automatically released, the to-be-conveyed object support table  3  that has been held at the lifted position is lowered to a lowering limit position by an effect of the cam rail  40  with the crosslink mechanism  12 . 
   The height of the lifted position of the to-be-conveyed object support table  3  in the specific section is determined by the thrusting height of the to-be-operated portion  14  (cam follower roller  31 ) by the cam rail  40 , that is, the height of the cam rail  40 , however, as shown in  FIG. 7 , when a specific section where a high cam rail  40 H to lift the to-be-conveyed object support table  3  to a high level H has been laid down and a specific section where a low cam rail  40 L to lift the to-be-conveyed object support table  3  to a low level L has been laid down are mixed in the conveying route of the conveying traveler  1 , it is sufficient to provide concave latching portions  34   b  that correspond to a position of the common slide fulcrum shaft  25  (to-be-latched portions  33 ) when the crosslinks  13   a  and  13   b  are thrust up by the cam rail  40 H and concave latching portions  34   c  that correspond to a position of the common slide fulcrum shaft  25  (to-be-latched portions  33 ) when the crosslinks  13   a  and  13   b  are thrust up by the cam rail  40 L side by side in the back and forth direction. 
   According to the configuration, when the to-be-conveyed object support table  3  has been lifted to the high level H by the cam rail  40 H, the common slide fulcrum shaft  25  (to-be-latched portions  33 ) of the crosslinks  13   a  and  13   b  is locked by the concave latching portions  34   b  on the side closer to the spindles  36  of the latches  34 , and when the to-be-conveyed object support table  3  has been lifted to the low level L by the cam rail  40 L, the common slide fulcrum shaft  25  (to-be-latched portions  33 ) of the crosslinks  13   a  and  13   b  is locked by the concave latching portions  34   c  on the side distant from the spindles  36  of the latches  34 . In addition, in both cases of the specific section with the cam rail  40 H and specific section with the cam rail  40 L, the unlocking cam  41  is laid down at the end portion as shown in  FIG. 8 . The unlocking cam  41  has a height to allow working on the cam follower rollers  39  of the latches  34  so as to push up the latches  34  to a height where both of the concave latching portions  34   b  and  34   c  leave upward further from a slide route of the common slide fulcrum shaft  25  (to-be-latched portions  33 ) and a length to allow keeping the same pushed up until the common slide fulcrum  25  (to-be-latched portions  33 ) that slides rearward leaves rearward further than these concave latching portions  34   b  and  34   c , and can release a lock in a standing condition of the crosslinks  13   a  and  13   b  before the to-be-conveyed object support table  3  starts lowering. 
   In the above-described embodiment, the two front and rear concave latching portions  34   b  and  34   c  have been provided in each latch  43 , however, a latch only with the concave latching portion  34   b  to lock the crosslinks  13   a  and  13   b  in a standing condition when the to-be-conveyed object support table  3  is lifted to the high level H by the cam rail  40 H and a latch only with the concave latching portion  34   c  to lock the crosslinks  13   a  and  13   b  in a standing condition when the to-be-conveyed object support table  3  is lifted to the low level L by the cam rail  40 L may be separately provided. In this case, it is necessary to structure the unlocking cam  41  that pushes up at least one latch with the concave latching portion  34   b  so as to simultaneously push up the other latch with the concave latching portion  34   c  in order to prevent the common slide fulcrum shaft  25  (to-be-latched portion  33 ) that slides rearward from the position of the concave latching portions  34   b  from again being engaged with the concave latching portion  34   c  of the other latch. 
   Moreover, in the above-described embodiment, as the to-be-operated portion  14  of the crosslink mechanism  12 , the cam follower roller  31  has been provided at a position, of the links  15   a  and  15   b  to compose the crosslinks  13   a  and  13   b , close to the position fixing fulcrum shafts  19  of the links  15   a  having the position fixing fulcrum shafts  19  on the conveying traveler  1  side, however, as shown in  FIG. 1A , the to-be-operated portion  14  may be composed of a lifting/lowering rod  42  supported by the conveying traveler body  1  so as to be vertically liftable and lowerable. In this case, at the lower end of the lifting/lowering rod  42 , a cam follower roller to work on the cam rail  40  is provided, and at the upper end of the lifting/lowering rod  42 , a thrusting table to thrust up the roller supported about an axis on the links  15   a  side is provided. Accordingly, as a result of the cam rail  40  thrusting up the lifting/lowering rod  42 , the lifting/lowering rod  42  makes the crosslinks  13   a  and  13   b  stand up via the thrusting table at the upper end thereof and the roller on the links  15   a  side. A thrusting position on the crosslink side by the lifting/lowering rod  42  may be the position of the common center fulcrum shaft  16  where the links  15   a  and  15   b  are mutually pivotally mounted. When the to-be-operated portion  14  formed of such a lifting/lowering rod  42  is employed, since there is a high possibility that the lifting/lowering rod  42  is broken by buckling in a case of a conveying apparatus that handles a major-load to-be-conveyed object, it is particularly effective to use also the locking means  32  in the present invention. 
   Moreover, as the to-be-latched portions  33  on the crosslinks  13   a  and  13   b  side with which the locking latches  34  are engaged, the common slide fulcrum shaft  25  on the conveying traveler body  1  side in the crosslinks  13   a  and  13   b  has been used, however, if such a common slide fulcrum shaft  25  does not exist, a member to form the to-be-latched portions  33  with which the locking latches  34  are engaged may be provided, near the slide fulcrum shaft  25 , as an annex to the links  15   b.    
   The conveying apparatus with a lifting/lowering to-be-conveyed object support table according to the present invention can be utilized, on an automobile assembly line, as a conveying apparatus that allows conveying a vehicle body (to-be-conveyed object) to which various parts are attached while mounting the same on a to-be-conveyed object support table  3  and keeping, in a section of a parts fitting operation (specific section described in the embodiment where the cam rail  40  has been laid down), the vehicle body (to-be-conveyed object support table  3 ) lifted to a level where an operator on the conveying traveler body  1  can easily carry out a parts fitting operation.