Suspended work platform with an integrated rescue system and a method for rescuing a worker

Abstract

A suspended work platform with an integrated rescue system and a method for rescuing a worker is used to quickly rescue workers from an elevated position. The system incorporates a work hoist and a rescue device cooperating with a platform rope. The work hoist is attached to the work platform. A worker changes the elevation of the work platform by operating a work input device of a work hoist control system. The rescue device cooperates with the platform rope and is attached above the work platform to a tie-off location. A rescuer operates the rescue device to perform a rescue of the worker when necessary. The rescue system may also include an independent fall arrest system having a descent control system with a fall arrest rope attached to the worker and to the tie-off location.

1 . A suspended work platform with an integrated rescue system ( 50 ) for rescuing a worker on a work platform ( 100 ) suspended from a tie-off point ( 20 ) on a structure ( 10 ) wherein the tie-off point ( 20 ) is above the work platform ( 100 ) and a fall surface ( 30 ) is below the work platform ( 100 ), comprising:
 (A) a platform rope ( 300 ) having a maximum extension length;   (B) a work hoist ( 200 ) having a work hoist motor ( 210 ), a work hoist traction mechanism ( 230 ) designed to cooperate with the platform rope ( 300 ), and a work hoist gear box ( 220 ) for transferring power from the work hoist motor ( 210 ) to the work hoist traction mechanism ( 230 ), wherein the work hoist ( 200 ) is attached to the work platform ( 100 );   (C) a work hoist control system ( 700 ) having a worker input device ( 710 ) accessible from the work platform ( 100 ), wherein the worker input device ( 710 ) is in operative communication with the work hoist ( 200 ), the worker input device ( 710 ), and the worker input device ( 710 ) controls the work hoist motor ( 210 ) such that the work hoist ( 200 ) ascends and descends along the platform rope ( 300 ); and   (D) a rescue device ( 400 ) having a rescue traction mechanism ( 430 ) designed to cooperate with the platform rope ( 300 ), wherein the rescue device ( 400 ) is attached to the tie-off point ( 20 ), the rescue device ( 400 ) is operated at the tie-off point ( 20 ), the platform rope ( 300 ) extends downward from the rescue device ( 400 ) to suspend the work platform ( 100 ) by the work hoist ( 200 ), and the rescue device ( 400 ) controllably lowers the platform rope ( 300 ) and the work platform ( 100 ) to near the fall surface ( 30 ) before the maximum extension length of the platform rope ( 300 ) is reached.   
   
   
       2 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 1 , wherein the work platform ( 100 ) travels on the platform rope ( 300 ) between a highest working elevation ( 110 ) and a fall surface exit elevation ( 120 ), thereby defining a working elevation range ( 130 ), wherein the highest working elevation ( 110 ) is the elevation at which the work hoist ( 200 ) nears the rescue device ( 400 ) and is prevented from ascending further towards the rescue device ( 400 ), the fall surface exit elevation ( 120 ) is the elevation at which the work platform ( 100 ) cannot be lowered any further, and the working elevation range ( 130 ) is the difference between the highest working elevation ( 110 ) and the fall surface exit elevation ( 120 ), wherein the maximum extension length of the platform rope ( 300 ) is at least approximately one hundred and fifty percent of the working elevation range ( 130 ) of the work platform ( 100 ). 
   
   
       3 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 1 , wherein the work platform ( 100 ) travels on the platform rope ( 300 ) between a highest working elevation ( 110 ) and a fall surface exit elevation ( 120 ), thereby defining a working elevation range ( 130 ), wherein the highest working elevation ( 110 ) is the elevation at which the work hoist ( 200 ) nears the rescue device ( 400 ) and is prevented from ascending further towards the rescue device ( 400 ), the fall surface exit elevation ( 120 ) is the elevation at which the work platform ( 100 ) cannot be lowered any further, and the working elevation range ( 130 ) is the difference between the highest working elevation ( 110 ) and the fall surface exit elevation ( 120 ), wherein the maximum extension length of the platform rope ( 300 ) is at least approximately one hundred and ninety percent of the working elevation range ( 130 ) of the work platform ( 100 ). 
   
   
       4 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 1 , wherein the rescue device ( 400 ) has a rescue traction brake ( 440 ) designed to engage the rescue traction mechanism ( 430 ), a rescue over-speed brake ( 450 ) for stopping uncontrolled passage of the platform rope ( 300 ) through the rescue device ( 400 ), and a rescue controlled descent device ( 460 ) that releases the rescue traction brake ( 440 ) allowing controlled withdrawal of the platform rope ( 300 ) through the rescue device ( 400 ). 
   
   
       5 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 1 , wherein the work hoist ( 200 ) further includes a work hoist controlled descent device ( 260 ) for controlling the non-powered passage of the platform rope ( 300 ) through the work hoist ( 200 ) allowing the work platform ( 100 ) to descend by gravity along the platform rope ( 300 ). 
   
   
       6 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 4 , wherein the rescue device ( 400 ) is a rescue hoist ( 402 ) having a rescue hoist motor ( 410 ) and a rescue hoist gear box ( 420 ) for transferring power from the rescue hoist motor ( 410 ) to the rescue traction mechanism ( 430 ), and further including a rescue hoist control system ( 800 ) having a rescuer input device ( 810 ), wherein the rescue hoist control system ( 800 ) is in operative communication with the rescue hoist ( 402 ) and the work hoist ( 200 ) and the rescuer input device ( 810 ) controls the rescue hoist motor ( 410 ) to extend and retract the platform rope ( 300 ). 
   
   
       7 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 6 , wherein the rescuer input device ( 810 ) further includes a stop button ( 812 ), wherein the stop button ( 812 ) disconnects the rescue hoist motor ( 410 ) from power, whereby the rescue hoist ( 402 ) is inoperable when the stop button ( 812 ) is engaged. 
   
   
       8 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 5 , wherein the rescue hoist control system ( 800 ) further includes a work hoist lockout ( 820 ), wherein the work hoist lockout ( 820 ) disconnects the work hoist ( 200 ) from power, whereby the work hoist ( 200 ) is inoperable when the work hoist lockout ( 820 ) is engaged. 
   
   
       9 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 5 , wherein the rescue hoist control system ( 800 ) further includes a power supply tag-out mechanism ( 830 ), wherein the power supply tag-out mechanism ( 830 ) disconnects the rescue hoist motor ( 410 ) and the rescuer input device ( 810 ) from power until the rescuer operates the power supply tag-out mechanism ( 830 ) to reconnect power. 
   
   
       10 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 5 , the rescuer input device ( 810 ) further includes a directional control button ( 814 ), wherein the rescue traction brake ( 440 ) releasably engages the rescue traction mechanism ( 430 ) and the directional control button ( 814 ) is in operative communication with the rescue traction brake ( 440 ) and the rescue hoist motor ( 410 ), whereby when the directional control button ( 814 ) is operated the rescue traction brake ( 440 ) releases the rescue traction mechanism ( 430 ) and causes the rescue hoist motor ( 410 ) to rotate. 
   
   
       11 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 1 , further including an independent fall arrest system ( 600 ) having a fall arrest rope ( 610 ) and a fall arrest device ( 620 ), wherein the fall arrest rope ( 610 ) has a worker attachment portion ( 612 ) fastened to the worker and a tie-off point attachment portion ( 614 ) attached to the tie-off point ( 20 ), whereby when the worker is suspended by the independent fall arrest system ( 600 ), the rescuer lowers the worker by operating the fall arrest device ( 620 ) to controllably extend the fall arrest rope ( 610 ) under the influence of gravity. 
   
   
       12 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 5 , wherein the rescuer input device ( 810 ) is accessible near the tie-off point ( 20 ). 
   
   
       13 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 5 , wherein the rescuer input device ( 810 ) is not accessible from the work platform ( 100 ). 
   
   
       14 . A suspended work platform with an integrated rescue system ( 50 ) for rescuing a worker on a work platform ( 100 ) having a highest working elevation ( 110 ), a fall surface exit elevation ( 120 ), and a working elevation range ( 130 ) and the work platform ( 100 ) is suspended from a tie-off point ( 20 ) on a structure ( 10 ) having a wall ( 12 ) with an interior surface ( 14 ) and an exterior surface ( 16 ), and an access port ( 18 ) extending from the interior surface ( 14 ) to the exterior surface ( 16 ), wherein the tie-off point ( 20 ) is outside the structure ( 10 ) and the work platform ( 100 ) is inside the structure ( 10 ) with a fall surface ( 30 ) below the work platform ( 100 ), comprising:
 (A) a platform rope ( 300 ) having a maximum extension length;   (B) a work hoist ( 200 ) having a work hoist motor ( 210 ), a work hoist traction mechanism ( 230 ) designed to cooperate with the platform rope ( 300 ), a work hoist gear box ( 220 ) for transferring power from the work hoist motor ( 210 ) to the work hoist traction mechanism ( 230 ), and a work hoist controlled descent device ( 260 ) for controlling the non-powered passage of the platform rope ( 300 ) through the work hoist ( 200 ), wherein the work hoist ( 200 ) is attached to the work platform ( 100 ) and operation of the work hoist controlled descent device ( 260 ) allows the work platform ( 100 ) to descend by gravity along the platform rope ( 300 ) to the fall surface exit elevation ( 120 ) where the work platform ( 100 ) cannot be lowered any further;   (C) a work hoist control system ( 700 ) having a worker input device ( 710 ) accessible from the work platform ( 100 ), the work hoist control system ( 700 ) is in operative communication with the worker input device ( 710 ) and the work hoist ( 200 ), wherein the worker input device ( 710 ) controls the work hoist motor ( 210 ) such that the work hoist ( 200 ) ascends and descends along the platform rope ( 300 );   (D) a rescue hoist ( 402 ) attached to the tie-off point ( 20 ), the rescue hoist ( 402 ) having a rescue hoist motor ( 410 ) and a rescue hoist gear box ( 420 ) for transferring power from the rescue hoist motor ( 410 ), a rescue traction mechanism ( 430 ) designed to cooperate with the platform rope ( 300 ), a rescue traction brake ( 440 ) designed to engage the rescue traction mechanism ( 430 ), a rescue over-speed brake ( 450 ) for stopping uncontrolled passage of the platform rope ( 300 ) through the rescue hoist ( 402 ), and a rescue controlled descent device ( 460 ) that releases the rescue traction brake ( 440 ) allowing controlled withdraw of the platform rope ( 300 ) through the rescue hoist ( 402 ), wherein   (i) the platform rope ( 300 ) extends downward from the rescue hoist ( 402 ) through the access port ( 18 ) to suspend the work platform ( 100 ) by the work hoist ( 200 ),   (ii) the work platform ( 100 ) travels on the platform rope ( 300 ) between a highest working elevation ( 110 ) and a fall surface elevation ( 120 ), thereby defining a working elevation range ( 130 ), and   (iii) the maximum extension length of the platform rope ( 300 ) is at least approximately one hundred and fifty percent of the working elevation range ( 130 ) of the work platform ( 100 );   (E) a rescue hoist control system ( 800 ) in operative communication with the rescue hoist ( 402 ) and the work hoist ( 200 ), the rescue hoist control system ( 800 ) having a rescuer input device ( 810 ), a work hoist lockout ( 820 ), and a power supply tag-out mechanism ( 830 ), wherein   (i) the rescuer input device ( 810 ) is in operative communication with the rescue traction brake ( 440 ) and the rescue hoist motor ( 410 );   (ii) the rescuer input device ( 810 ) has a stop button ( 812 ) and a directional control button ( 814 ), wherein
 (a) the stop button ( 812 ) disconnects the rescue hoist motor ( 410 ) from power, whereby the rescue hoist ( 402 ) is inoperable when the stop button ( 812 ) is engaged; and 
 (b) the directional control button ( 814 ) causes the rescue traction brake ( 440 ) to disengage from the rescue traction mechanism ( 430 ) while causing the rescue hoist motor ( 410 ) to extend or retract the platform rope ( 300 ); and 
   (iii) the work hoist lockout ( 820 ) disconnects the work hoist ( 200 ) from power, whereby the work hoist ( 200 ) is inoperable when the work hoist lockout ( 820 ) is engaged; and   (F) an independent fall arrest system ( 600 ) having a fall arrest rope ( 610 ) formed with a worker attachment portion ( 612 ) and a tie-off point attachment portion ( 614 ), wherein the worker attachment portion ( 612 ) is fastened to the worker, the fall arrest rope ( 610 ) extends through the access port ( 18 ), and the tie-off point attachment portion ( 614 ) of the fall arrest rope ( 610 ) engages a fall arrest device ( 620 ) and is attached to the tie-off point ( 20 ), such that the independent fall arrest system ( 600 ) suspends the worker, and the fall arrest device ( 620 ) allows controlled withdraw of the fall arrest rope ( 610 ) to lower the worker to the fall surface ( 30 ).   
   
   
       15 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 14 , wherein the rescuer input device ( 810 ) is accessible near the tie-off point ( 20 ) and the rescuer input device ( 810 ) is outside the structure ( 10 ). 
   
   
       16 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 14 , wherein the rescuer input device ( 810 ) is not accessible from the work platform ( 100 ). 
   
   
       17 . The suspended work platform with an integrated rescue system ( 50 ) of  claim 14 , wherein the power supply tag-out mechanism ( 830 ) disconnects the rescue hoist motor ( 410 ) and the rescuer input device ( 810 ) from power until the rescuer operates the power supply tag-out mechanism ( 830 ) to reconnect power. 
   
   
       18 . A method for rescuing a worker from an elevated position, comprising:
 moving a work platform ( 100 ), wherein a rescuer operates a rescue hoist ( 402 ), the rescue hoist ( 402 ) is connected to a tie-off point ( 20 ), the rescue hoist ( 402 ) has a rescue hoist motor ( 410 ) and a rescue hoist gear box ( 420 ) for transferring power from the rescue hoist motor ( 410 ) to the rescue traction mechanism ( 430 ), the rescue hoist ( 402 ) extends and retracts a platform rope ( 300 ), the platform rope ( 300 ) is engaged by a work hoist ( 200 ), and the work hoist ( 200 ) is attached to the work platform ( 100 ), and wherein the rescuer operates the rescue hoist ( 402 ) by   (i) resetting a stop button ( 812 ), wherein the stop button ( 812 ) prevents the rescue hoist ( 402 ) from receiving power until the rescuer resets the stop button ( 812 );   (ii) deactivating a rescue over-speed brake ( 450 ), wherein the rescue over-speed brake ( 450 ) prevents downward motion of the platform rope ( 300 ) while engaged, and once deactivated the rescue over-speed brake ( 450 ) prevents uncontrolled withdraw of the platform rope ( 300 ) through the rescue hoist ( 402 );   (iii) disengaging a power supply tag-out mechanism ( 830 ), wherein the power supply tag-out mechanism ( 830 ) prevents the rescue hoist ( 402 ) from operating while engaged; and   (iv) operating a directional control button ( 814 ) which causes a rescue traction brake ( 440 ) to releasably disengage a rescue traction mechanism ( 430 ) which allows the rescue hoist ( 402 ) to move the work platform ( 100 ) and the worker.   
   
   
       19 . The method for rescuing the worker of  claim 18 , further including the step of:
 activating a work hoist lockout ( 820 ) following the resetting of the stop button ( 812 ), wherein the work hoist lockout ( 820 ) prevents the work hoist ( 200 ) from operating.   
   
   
       20 . The method for rescuing the worker of  claim 18 , wherein when the rescuer operates the rescue hoist ( 402 ), the work platform ( 100 ) moves from a highest working elevation ( 110 ) to a fall surface exit elevation ( 120 ) at a rate of approximately 35 feet per minute, wherein the highest working elevation ( 110 ) is the elevation at which the work hoist ( 200 ) is near the rescue hoist ( 402 ) and is prevented from ascending further towards the rescue hoist ( 402 ), and the fall surface exit elevation ( 120 ) is the elevation at which the work platform ( 100 ) cannot be lowered any further.