Abstract:
A safety platform for repair of a hydraulic elevator adapted to be attached to an underside of the elevator car to militate against vertical movement of the elevator car while repairs are being conducted on the hydraulic elevator.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an elevator safety platform and more particularly to a safety platform for hydraulic elevator repair.  
       BACKGROUND OF THE INVENTION  
       [0002]     A hydraulic type elevator is operated by a hydraulic system including a jack assembly, a piston assembly, and a network of oil lines. Repairing one of the above components of the hydraulic elevator often requires an elevator mechanic or building maintenance personnel to enter a hoistway under an elevator car while conducting the repairs. Persons that enter the hoistway may suffer serious or fatal accidents if the elevator car moves unexpectedly. Such accidents commonly occur in a pit where the person is crushed by the unexpected movement of the elevator car.  
         [0003]     A safety system commonly employed to prevent such accidents is the use of a safety switch located in the elevator car. The mechanic typically will enter the elevator car while parked at a specified floor and manually transfer the switch from a normal mode to an inspection mode. Such a system is ineffective in a hydraulic elevator if there is a rupture in one of the components causing a loss of hydraulic fluid.  
         [0004]     It would be desirable to produce a hydraulic elevator repair safety platform for use in elevator hoistways of varying dimensions which militates against vertical movement of an elevator car during repair of the elevator.  
       SUMMARY OF THE INVENTION  
       [0005]     Consistent and consonant with the present invention, a hydraulic elevator repair safety platform for use in elevator hoistways of varying dimensions which militates against vertical movement of an elevator car during repair of the elevator, has surprisingly been discovered.  
         [0006]     The hydraulic elevator repair safety platform comprises an elongate central beam having a first end and a second end, the beam adapted to be connected to an elevator car; a guide clamp assembly connected to the beam and adapted to be received by an elevator guide rail system, the guide clamp assembly having an actuation arm actuated by a downward movement of the elevator car, whereby the actuation of the actuation arm causes the guide clamp assembly to grip the guide rail system which facilitates immobilization of the elevator car. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The above, as well as other objects, features, and advantages of the present invention will be understood from the detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings, in which:  
         [0008]      FIG. 1  is a front elevation view of a hydraulic elevator repair safety platform incorporating the features of the invention and schematically showing a portion of an elevator car;  
         [0009]      FIG. 2  is a side elevation view showing an end portion of the hydraulic elevator repair safety platform illustrated in  FIG. 1 ;  
         [0010]      FIG. 3  is a top plan view of the end portion of the hydraulic elevator repair safety platform illustrated in  FIG. 2 ;  
         [0011]      FIG. 4  is a front elevation view showing a central beam of the hydraulic elevator repair safety platform illustrated in  FIG. 1 ; and  
         [0012]      FIG. 5  is a side elevation view of the central beam portion illustrated in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     Referring now to the drawings, and particularly  FIG. 1 , there is shown generally at  10  a hydraulic elevator repair safety platform incorporating the features of the invention. The safety platform  10  includes an elongate central beam  12 . In the embodiment shown, a pair of spaced apart steel channel sections comprise the central beam  12 , as clearly shown in  FIG. 5 . It is understood that other beam structures such as a single beam, for example, could be used without departing from the scope and spirit of the invention. A plurality of rigging members  14  depend from the channel sections of the central beam  12 . As shown in  FIGS. 1, 4 , and  5 , the rigging members  14  include pairs of U-bolts  14   a  with each U-bolt of a pair attached to an associated one of the channel sections. A length of piping or rod  14   b  extends between the U-bolts of each pair and is held therein to maintain the spaced relationship of the channel sections. A plurality of holes  16  are disposed at each end of each of the channel sections of the central beam  12 .  
         [0014]     Each end of the central beam  12  has an end portion  18  connected thereto. A plurality of holes  20  are formed in the end portions  18 , and can be selectively aligned with the holes  16  of the central beam  12  to receive fasteners (not shown) and to facilitate an adjustment of the overall length of the safety platform  10 . In the embodiment shown, a pair of spaced apart steel channel sections  18   a  comprise the sides of the end portions  18 , as clearly shown in  FIG. 2 . The channel sections  18   a  are connected by top and bottom plates  18   b  attached by suitable fasteners. It is understood that other end portion structures could be used without departing from the scope and spirit of the invention. A slot  22  is formed in one end of each of the plates  18   b  of the end portions  18 , as illustrated in  FIGS. 2 and 3 . The slots  22  of the end portions  18  receive an elevator guide rail  24  therein as shown in  FIG. 3 . The guide rail  24  is attached to a wall of an elevator hoistway (not shown). In the embodiment shown, the guide rail  24  is a T-rail with the stem received in the slot  22 . It is understood that other guide rails could be used without departing from the scope and spirit of the invention.  
         [0015]     An upwardly extending adapter guide shoe plate  26  is disposed on the top one of the plates  18   b  of each of the end portions  18 . The guide shoe plates  26  are adapted to be connected to an elevator car  27 . The connection may be achieved by removing roller/slide guides (not shown) from the underside of the elevator car  27  and attaching the guide shoe plates  26  to the elevator car  27  at the point where the roller/slide guides were removed.  
         [0016]     As shown in  FIG. 1 , a guide clamp assembly  29  is connected to the safety platform  10  on the end portions  18 . The guide clamp assembly  29  includes a pair of guide clamps  28 , an adjustable guide clamp linkage  30 , and a safety cable  32 . Such a guide clamp assembly  29  can be purchased as an assembly commercially available as a Type “A” Instantaneous Model 540 Safety from Hollister Whitney, for example. The safety cable  32  is typically connected to a ceiling or a wall of the elevator hoistway. The safety cable  32  is also connected to one of the actuating arms  34  and through the linkage  30  to the other one of the arms  34 . Each of the actuating arms  34  is connected to a clamping system (not shown) within the associated guide clamp  28  which cooperates to act as a brake. The linkage  30  facilitates simultaneous actuation of the actuating arms  34 . A slot  36  formed in the guide clamp  28 , as illustrated in  FIG. 2 , receives the guide rail  24  therein.  
         [0017]     A pair of guide shoes  38  are connected to each of the guide clamps  28 . A gap or space  40  is formed between the guide shoes  38  to receive the guide rail  24  therein, as shown in  FIG. 2 . Such a guide shoe  38  can be purchased such as is commercially available as Model No. 371 Guide Shoe from Hollister Whitney, for example.  
         [0018]     When repair or maintenance of a hydraulic elevator is necessary, the elevator car  27  can be positioned as desired. The safety platform  10  is then attached to the underside of the elevator car  27  using the guide shoe plates  26 . Adjustment of the overall length of the safety platform  10  is accomplished by aligning the apertures  16  of the central beam  12  with the holes  20  of the end portions  18  and bolting the central beam  12  to the end portions  18  to achieve the desired length.  
         [0019]     The safety cable  32  is then connected to the wall or the ceiling of the elevator hoistway. The elevator car  27  is caused to move downwardly, thereby tensioning the safety cable  32  and causing actuation of the actuating arms  34 . The guide clamp linkage  30  facilitates simultaneous actuation of the actuating arms  34 . The clamping system within the guide clamps  28  is caused to grip the guide rail  24  with the guide shoes  38 , thus causing the downward movement of the elevator car  27  to stop. Further downward movement of the elevator car  27  will cause the clamping system within the guide clamps  28  to more tightly grip the guide rail  24 , thus immobilizing the elevator car  27  within the elevator hoistway. The guide shoes  38  maintain proper alignment of the guide clamps  28  and entire safety platform  10  during the use of the safety platform  10  during the repair or maintenance operation.  
         [0020]     Once the elevator car  27  is immobilized, an elevator mechanic or building maintenance personnel can safely conduct the repair or maintenance. The rigging members  14  provide a point for connection of a hoist or other tools which will facilitate removal of a jack assembly or other hydraulic elevator components.  
         [0021]     When the desired repair or maintenance operation has been completed, the safety platform  10  can be removed and the elevator car  27  returned to normal operation.  
         [0022]     From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.