Abstract:
An elevator including a cage configured to ascend and descend in an elevator shaft, and at least one railing member disposed along at top edge of the cage and configured to be adjustable in height so that during performance of maintenance by a maintenance person, the railing is adjusted to be in an upright position, and is otherwise maintained in a position lower than a highest protruding object existing on the top of the cage.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims benefit of priority to Japanese Patent Applications No. JP10-249873 filed Sep. 3, 1998 and No. JP10-287843 filed Oct. 9, 1998, the entire contents of which are incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an elevator with improved railings provided on an upper side of a passenger cage along the top edges thereof. 
     2. Discussion of the Background 
     In general, elevators have been installed in a high rise building so that residents or the like can easily get to the desired upper or lower floors. 
     The conventional elevator, as shown in FIG. 1, is operated in an elevator shaft  1  extending vertically in the building, and includes a pair of guide rails  2  installed in the shaft  1 , a cage  4  movably supported between the guide rails  2  via a cage frame  3 , and a drive system  5  moving the cage  4  up and down. The drive system  5  is composed of cables (only one is shown)  6 , two car sheaves  7 , a counter weight sheave  8 , a counter weight  9 , and a hoisting machine  10  disposed in the upper part of the shaft  1  for driving the cables  6 . 
     In this type of elevator where the hoisting machine  10  is disposed in the upper part of the shaft  1 , thereby dispensing with a machine room located right above the shaft  1  in which a hoisting machine, a control panel and the like is conventionally installed, it is especially required to reduce the overhead measurements at the installation of the elevator so that the building space other than the shaft  1  can be used effectively. (The overhead measurements refer to a distance between a floor of the cage  4  and a ceiling of the shaft  1  at the time the cage  4  stops at the upper most floor.) 
     Practically speaking, the overhead measurements are determined by a distance between the highest object on the cage  4 , that is guide shoes  11 , and the lowest object on the ceiling part of the shaft  1 , that is the ceiling of the shaft  1 . Further, the distance from the highest object on the cage  4  to the lowest object on the ceiling of the shaft  1  can be affected by conditions of other components in the shaft  1  such as a stroke of a counter weight oil buffer (not shown), or a distance between the counter weight oil buffer and the counter weight  8 . 
     Thus, to realize an elevator with small overhead measurements, it is necessary to reduce a distance between the highest object on the cage  4  and the ceiling of the shaft  1 . 
     Furthermore, elevators are required to be inspected periodically, and on such occasions, maintenance workers sometimes inspect the elevators riding on the upper side of the cage  4 . To ensure the safety of the maintenance workers, in general, railings  12  are provided on the upper side of the cage  4  along the side edges and back edge thereof. To realize an elevator with small overhead measurements, the height Y of railings  12  has to be lower than the height X of the highest object on the cage  4 , i.e. the guide shoe  11 . 
     However, if the height Y is lower than the height X, the railings  12  do not achieve the main object of ensuring the safety of the maintenance workers on the cage  4 . On the other hand, if the height Y of the railings  12  becomes higher, the overhead measurements become longer, and as a result, it becomes impossible to realize an elevator with small overhead measurements. 
     SUMMARY OF THE INVENTION 
     Accordingly, one object of the present invention is to provide a novel elevator with small overhead measurements and which can ensure the safety of maintenance workers on the cage during an inspection by means of railings. 
     This and other objects are achieved according to the present invention by providing a new and improved elevator including a cage configured to ascend and descend in an elevator shaft, and a railing member disposed on the cage along a top edge thereof and configured to be adjustable in height. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 is a schematic perspective view showing a conventional traction type elevator; 
     FIG. 2 is a perspective view of railings in FIG. 1; 
     FIG. 3 is a perspective view showing railing members of a first embodiment of the present invention in a contracted state; 
     FIG. 4 is another perspective view showing railing members of the first embodiment of the present invention in an expanded state; 
     FIG. 5 is a perspective view of railing member of a second embodiment of the present invention in a collapsed state; 
     FIG. 6 is a perspective view of railing member of a second embodiment of the present invention in an upright state; 
     FIG. 7 is a perspective view of one railing member of a third embodiment of the present invention; 
     FIG. 8 is a perspective view of railing members of a fourth embodiment of the present invention; 
     FIG. 9 is a perspective view of railing members of a fifth embodiment of the present invention; 
     FIG. 10 is a perspective view of a railing member of a sixth embodiment of the present invention; 
     FIG. 11 is a front view showing the railing member in FIG. 10; 
     FIG.  12 ( a ) is a perspective view of a railing member of a seventh embodiment of the present invention; 
     FIG.  12 ( b ) is a perspective view of the principal part of the railing member in FIG.  12 ( a ); 
     FIG.  13 ( a ) is a top view of a railing member of an eighth embodiment of the present invention; 
     FIG.  13 ( b ) is a front view of the railing member in FIG.  13 ( a ); 
     FIG. 14 is a front view of a railing member of a ninth embodiment of the present invention; 
     FIG.  15 ( a ) is a top view of a railing member of a tenth embodiment of the present invention; 
     FIG.  15 ( b ) is a front view of the railing member in FIG.  15 ( a ); 
     FIG. 16 is a front view of a railing member of an eleventh embodiment of the present invention; 
     FIG. 17 is a front view of a railing member of a twelfth embodiment of the present invention; 
     FIG. 18 is a front view of a railing member of a thirteenth embodiment of the present invention; and 
     FIG. 19 is a front view of a railing member of a fourteenth embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, where like reference numerals designate the same or corresponding parts throughout the several views, next described is a first embodiment of the present invention shown in FIG.  3  and FIG.  4 . 
     In this embodiment, since every component of the elevator other than railings  12  in FIG. 1 is the same structure as FIG. 1, there will be described only components of improved railings. 
     As shown in FIGS. 3 and 4, the railing members  23  are respectively formed in the shape of an inverted U and disposed at intervals on a cage  4  along the top side edges and the top back edge thereof. In FIG. 3, the railing member  23  disposed on the right side edge of the cage  4  is not shown, but only the railing members  23  disposed on the left side and the back side of the cage  4  are shown. 
     The railing members  23  are installed on the upper surface of the cage  4  so as to expand and contract vertically. 
     Each of the railing members  23  is composed of a pair of cylindrical pipes  21  standing on the cage  4  and a railing  20  having a pair of legs  20   a  movably inserted in the pipes  21  and extending from the upper ends thereof. The railing  20  is adjustable in height by inserting the legs  20   a  into the pipes  21  as shown in FIG.  3  and pulling the legs  20   a  out of the pipes  21  as shown in FIG.  4 . The height of each pipe  21  is set such that the height Y of the railing  20  at the time the legs  20   a  are entirely inserted the pipes  21  becomes lower than the height X of the highest protruded object on the cage  4 , typically the height of guide shoe  11 , for example. Thus, the railing  20  is contracted to a position lower than the height X of the highest protruded object on the cage  4  at the time of normal operation of the elevator, and expanded to a higher position to ensure the safety of a maintenance worker at the time of inspection of the elevator. 
     Further, a lock device such as a bolt  22  heading to the inside of the pipe  21  is screwed on one of the upper end surfaces of the pair of pipes  21  in order to lock the expanded railing  20  at a position ensuring the safety of a maintenance worker by pushing the legs  20   a  with a head of the bolt  22 . 
     According to the railing members  23  described above, since the legs  20   a  are entirely put into the pipes  21  as shown in FIG.  3  and the railings  20  is collapsed at the time of a normal operation of the elevator, the elevator can be installed in a building without increasing the overhead measurements. 
     Further, in case that a maintenance worker is inspecting the elevator riding on the cage  4 , since the legs  20   a  are pulled out of the pipes  21  and locked at a high position ensuring the safety of the maintenance worker by screwing the bolt  22 , the maintenance work can be performed securely. 
     Thus, the first embodiment can both reduce the over head measurements and ensure safety. Moreover, in the first embodiment, since the sliding railing members  23  are adopted, it is easy to design a railing height surely ensuring the safety of the maintenance worker by increasing the number of tiers of telescoping railings. 
     FIG.  5  and FIG. 6 are perspective views of railing members  33  of a second embodiment of the present invention, in which folding railing members are employed instead of sliding telescoping railings. The railing members  33  are disposed on the cage  4  along the top side edges and the top back edge thereof. In FIGS. 5 and 6, only the railing member  33  disposed on the left side of the cage  4  is shown. The railing members  33  disposed on the right side edge and the back side edge of the cage  4  are not shown for the sake of convenience. 
     Each of the railing members  33  is composed of a pair of hinge plates  31  mounted on the cage  4  so as to fold a railing  30  toward the center of the cage  4 . The railing  30  has a pair of legs  30   a  which when upright have sufficient height to ensure the safety of a maintenance worker and are respectively secured to turning plates  31   a  of the hinge plates  31 . In case of a normal operation of the elevator, as shown in FIG. 5, the railing  30  is folded down to the center of the cage  4  to a position lower than the height of the highest object on the cage  4 . When the maintenance worker inspects the elevator while riding on the cage  4 , the railing  30  is unfolded to the upright state as shown in FIG. 6 with enough height to ensure the safety of the maintenance worker. Further, a lock link  32  is attached to one of the hinge plates  31  in order to maintain the upright state of the railing  30 , so that the railing  30  does not fold from the upright state to the folded state as long as the lock is not released. 
     According to the railing members  33  described above, the same effects as the first embodiment can be achieved. Moreover, folding railings of the second embodiment potentially offer the advantage of increased upright height of the railings, depending on the width and depth of the cage  4 . 
     FIG. 7 is a perspective view of one railing member of a third embodiment of the present invention, in which the railing members  23  in the first embodiment shown in FIG. 3 are modified. 
     The railing members  24  of FIG. 7 are respectively formed in the shape of an inverted U and disposed at intervals along the top side edges and the top back edge of the cage  4  in the same way as the first embodiment in FIG.  3 . In FIG. 7, only the railing member  24  disposed on the right side edge of the cage  4  is shown. In this embodiment, the railing members  24  are installed on side surface of the cage  4  so as to expand and contract vertically. 
     Each of the railing members  24  is composed of a pair of cylindrical pipes  21  standing on the side of the cage  4  and a railing  20  having a pair of legs  20   a  movably inserted in the pipes  21  from the upper ends thereof. The railing  20  is adjustable in height by putting the legs  20   a  into the pipes  21  as shown in FIG.  7  and pulling the legs  20   a  out of the pipes  21 . The pipes  21  are secured on the side of the cage  4  with securing members  40 . 
     Further, a lock device such as a bolt  22  heading to the inside of the pipe  21  is screwed on one of the upper end surfaces of the pair of pipes  21  in order to lock the expanded railing  20  at a position ensuring the safety of a maintenance worker by pushing the legs  20   a  with a head of the bolt  22 . 
     According to the third embodiment, pipes  21  of relatively long length can be employed whereby railings  20  of sufficient height can easily be implemented. 
     FIG. 8 is a perspective view of railing members of a fourth embodiment of the present invention. The fourth embodiment modifies the first embodiment shown in FIG. 3, by adding connecting plates  50  to the components of the first embodiment. 
     In the fourth embodiment, the adjacent railings  20  are integrated at the upper portion thereof with one of the connecting plates  50  so that all of the railings  20  can simultaneously be returned to the folding state at the time of changing the elevator from an inspection state to a normal operation state. Thus, all railing members  23  can be moved up and down by operating one of the railings  20 . 
     According to the fourth embodiment, the railing members  23  can be prevented from colliding with the ceiling of the shaft  1  after returning the elevator to the normal operation state. 
     FIG. 9 is a perspective view of railing members of a fifth embodiment of the present invention, in which an operation prohibiting device  60 , which prohibits a normal operation of the elevator until the railings  20  return to a position lower than the highest object on the cage  4 , is added to the fourth embodiment. 
     The operation prohibiting device  60  is composed of a limit switch  61  which detects whether the railings  20  return to a proper position, and a controller  62 . The limit switch  61  outputs a confirmation signal to the controller  62  at the time the railings  20  return to a proper position for a normal operation of the elevator. The controller  62  outputs a permit signal to the hoisting machine  10  to allow a normal operation of the elevator only upon receiving the confirmation signal in order. That is, the elevator can not be operated until the railings  20  return to a position lower than the highest object on the cage  4 , i.e. the guide shoe  11 . 
     According to the fifth embodiment, even if it is attempted to operate the elevator in a normal operation is prevented, that is, the railings  20  remain higher than the guide shoe  11 , the normal operation is prevented, so that the safety of the elevator can be improved. 
     This operation prohibiting device  60  can be employed with railing members individually installed on the cage  4  as described in the first embodiment, the second embodiment or the third embodiment. In this case, as shown with a double dotted chain line in FIG. 4, plural limit switches  61  are attached to respective of the railing members  23 . 
     FIG. 10 is a perspective view of a railing member  78  of a sixth embodiment of the present invention. FIG. 11 is a front view showing the railing member  78  in FIG.  10 . 
     In this embodiment, at the time of an inspection, to insure safety of a maintenance worker as much as possible, a height of the railing member  78  is composed to be adjustable in height before the maintenance worker steps on the cage  4 . 
     That is, the railing member  78  is composed of a pair of first railing members  70  disposed on the cage  4  along the top side edges thereof so as to be adjustable in height, and a second railing member  75  disposed on the cage  4  along the top back side of thereof so as to be adjustable in height. The first railing members  70  and the second railing member  75  can be raised for inspection before the maintenance worker steps on the cage  4  from an elevator depot. 
     Each of the first railing members  70  is composed of a railing  71  formed in the shape of an inverted U and extending from the front side of the cage  4  to the back side. The railing  71  has two legs  71   a  mounted on stands  73  on the cage  4  via hinges  72  capable of turning toward the center of the cage  4 . Thus, as shown in FIG. 10, the first railing members  70  are installed on the cage  4  so as to stand upright and to fold toward the center of the cage  4  as indicated by double dotted chain lines. The first railing members  70  are folded and lain on top of the cage frame  3   a.    
     The second railing member  75  is composed of a chain  76  connected at opposite ends thereof to the back side ends of the railings  71 . The chain  76  is disposed between the railings  71  so as to achieve a desired height when the railings  71  stand upright. That is, the chain  76  becomes tight and loose according to up and down movement of the railings  71 , thereby changing its height. 
     Further, ratchets  77  are attached to respective front sides of the hinges  72  supporting the legs  71   a.  The ratchets  77  lock a turning part and a fixed part of the hinges together, thereby maintaining the upright state of the railings  71 . Furthermore, knobs  77   a  are respectively provided at the ratchets  77  in order to release the lock state of the ratchets  77 . Thus, the railing  71  and the chain  76  can be adjusted to a height suitable for an inspection at the elevator depot without stepping on the cage  4 . 
     According to the sixth embodiment, in case of inspection, the maintenance worker grabs one of the legs  71   a  and stands the railing  71  upright by leaning out of the elevator depot before stepping on the cage  4 , and then locks the hinge  72  with the ratchet  77 . The other railing  71  is lifted up and locked in the same way, as a result, both sides of the railings  71  are locked and kept in upright state as shown in FIG.  10  and FIG.  11 . After the inspection, the maintenance worker first steps out to the elevator depot, then releases the lock state of the ratchets  77  by operating the knobs  77   a,  and folds the railings  71  toward the center of the cage  4 . Thus, the height of the railings  71  and the chain  76  can be set to a position ensuring the safety of the maintenance worker before stepping on the cage  4 . 
     Accordingly, the maintenance worker can step on the cage  4  after ensuring the safety, and inspect the elevator in safety. 
     Further, since the railings  71  are mounted on the stands  73 , in case of standing the railings  71  upright, the overall height of the railing member  78  suitable for the safety of the maintenance worker becomes the height Y equal to the sum of the height Y 1  of the stands  73  and the height Y 2  of the railings  71  as shown in FIG.  11 . On the other hand, in case of folding the railings  71 , since only the railings  71  are folded, the railing member  78  can be housed in a small space. Furthermore, in case that the height of the railing member  78  is required to change due to a change of the type of the elevator, the same railings  71  can be used though the height of the stands  73  might be changed. 
     FIG.  12 ( a ) is a perspective view of a railing member of a seventh embodiment of the present invention. FIG.  12 ( b ) is a perspective view of a principal part of the railing member in FIG.  12 ( a ). 
     This embodiment modifies the sixth embodiment, substituting a folding railing member  83  for the chain  76  as the second railing member  75 . 
     The railing member  83  is composed of a railing  84  formed in the shape of an inverted U. The opposite end portions  84   b  of the railing  84  are formed in a crank, and pivotably supported on the cage  4  by means of a shaft bearing (not shown), thereby enabling the railing  84  to be lifted up to stand upright and to be folded toward the center of the cage  4  as shown in FIG.  12 ( a ). 
     One of the legs  71   a  adjacent to the railing  84  is formed in the same way as the end portion  84   b.  That is, one end portion  71   b  of the legs  71   a  is pivotably supported on the cage  4  as shown in FIG.  12 ( b ) by means of a shaft bearing (not shown). The both end portions  84   b  and  71   b  are connected by a gear member  86  composed of two bevel gears  85 . Thus, if the railings  71  are folded from their standing upright state, the railing  84  is folded together therewith. On the other hand, if the railings  71  are raised up to the standing upright state, the railing  84  also stands. Only one railing  71  need be manipulated to achieve such operation. 
     FIG.  13 ( a ) is a top view of a railing member of an eighth embodiment of the present invention. FIG.  13 ( b ) is a front view of the railing member in FIG.  13 ( a ). 
     This embodiment modifies the sixth embodiment, substituting a link railing member  91  for the chain  76  as the second railing member  75 . 
     The railing member  91  is composed of a pair of railings  90  pivotably connected at one of the ends thereof to respective back side ends of the railings  71 , with the other ends thereof connected together. Thus, as shown in FIG.  13 ( b ), with folding of the railings  71 , the railings  90  are moved downward and folded, turning at the connecting point  91   a.    
     Further, a lock device  92  is added to the railing member  91  in order to keep a desired railing position and to disperse and reduce a load to be added to the railings  90 . 
     The lock device  92  is composed of a nut  93  welded on back side of one of the railings  90 , and a bolt  94  to be screwed in the nut  93  through a hole (not shown) provided on the other railing  90  in correspondence with the location of the nut  93 . The railings  90  are locked in a straight line by means of the nut  93  and the body  94 . 
     FIG. 14 is a front view of a railing member of a ninth embodiment of the present invention. 
     This embodiment modifies the sixth embodiment, substituting a link railing member  100  for the chain  76  as the second railing member  75 . 
     The railing member  100  is composed of a pair of first railings  101  and  103  pivotably connected at one end of each thereof to respective back side ends of the railings  71 , and a parallel railing  102  pivotably connected at opposite ends thereof to respective opposite ends of the first railings  101  and  103 . Thus, as shown in FIG. 14, with folding of the railings  71 , the railing member  100  is moved downward and folded pivoting on their fulcrums. 
     According to the ninth embodiment, the entire folded height H of the railing member  100  can be lowered. 
     FIG.  15 ( a ) is a top view of a railing member of a tenth embodiment of the present invention. FIG.  15 ( b ) is a front view of the railing member in FIG.  15 ( a ). 
     This embodiment modifies the sixth embodiment, substituting a slide railing member  108  for the chain  76  as the second railing member  75 . 
     The railing member  108  is composed of a railing  106  having a pair of slit rails  105  extending between the railings  71 , and a pair of cam rollers  107  attached to respective back sides of the railings  71  and guided by the rails  105 . Thus, as shown in FIG.  15 ( b ), with folding of the railings  71 , the railing member  108  is moved downward and folded, being guided by the cam rollers  107  and the slit rails  105 . 
     The slit rails  105  can be substituted for a guide rail attached to a side of the railing  106  without a slit. 
     FIG. 16 is a front view of a railing member of an eleventh embodiment of the present invention. 
     This embodiment modifies the sixth embodiment, substituting an elastic railing member  112  for the chain  76  as the second railing member  75 . 
     The railing member  112  is composed of a pair of cylinders  111  each pivotably connected at one end thereof to respective back sides of the railings  71 , and an elastic member  110  connected at opposite ends thereof to inside of the cylinders  111 . Thus, as shown in FIG. 16, with folding of the railings  71 , the railing member  112  is moved downward, and the elastic member  110  is contracted. 
     FIG. 17 is a front view of a railing member of a twelfth embodiment of the present invention. 
     This embodiment modifies the sixth embodiment in FIG. 10, adding an operation prohibiting device  120 , which prohibits a normal operation of the elevator until the railings  71  return to a position lower than the highest object on the cage  4 , to the sixth embodiment. 
     The operation prohibiting device  120  is composed of two limit switches  121  mounted on the cage  4  via stands  123  for detecting whether the railings  71  return to a proper position, and a controller  122 . The limit switches  121  output confirmation signals to the controller  122  at the time the railings  71  return to a proper position for a normal operation of the elevator. The controller  122  outputs a permit signal to the hoisting machine  10  only upon receiving both confirmation signals from each limit switch  121  in order to allow a normal operation of the elevator. That is, the elevator can not be operated until the railings  71  return to a position lower than the highest object on the cage  4 . 
     FIG. 18 is a front view of a railing member of a thirteenth embodiment of the present invention. 
     This embodiment modifies the twelfth embodiment of FIG. 17, by mounting the limit switches  121  on the railings  71 . That is, the projections  121   a  of the limit switches  121  are mounted on respective of the railings  71  such that the projections  121   a  contact stands  124  at the time the railings  71  fold down. 
     According to the thirteenth embodiment, similarly the elevator can not be operated until the railings  71  return to a position lower than the highest object on the cage  4 . 
     FIG. 19 is a front view of a railing member of a fourteenth embodiment of the present invention. 
     This embodiment modifies the twelfth embodiment in FIG. 17, substituting a switch device  125  for the limit switches  121 . 
     The switch device  125  is composed of a turning switch  125   a  installed on an upper side of one of the railings  71 , and a plate  126  attached on an upper side of the other railing  71  for switching on and off the turning switch  125   a  by contacting the turning switch  125   a.  Thus, only when both railings  71  are folded properly, will the turning switch  125   a  contact the plate  126 , and only then will the switch device  125  output the confirmation signal to the controller  122 . 
     According to the fourteenth embodiment, it is possible to detect whether both railings  71  are folded properly by means of only one switch  125   a.    
     Various modifications and variations are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.