Patent Publication Number: US-8979148-B1

Title: Fly jib for a crane and method of use

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     None 
     TECHNICAL FIELD 
     The present invention pertains generally to cranes and the use of same for moving loads, and more particularly to a fly jib which is used to position the lifted load. 
     BACKGROUND OF THE INVENTION 
     A fly jib is a lifting device which assists a crane operator in picking and placing a load at a target area. A fly jib is particularly useful in that it allows the crane operator to place the load, such as construction materials, inside a multistory building. A problem exist however in that the fly jib has no rotation mechanism, and as such must be manually rotated by personnel using long poles to align the load with the target area. Additionally, the fly jib does not have a way of extending its length so that the load can be moved toward the target area without having to move the supporting crane. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a fly jib which overcomes the problems of prior art devices. The fly jib disclosed herein can both selectively rotate the load to a desired angular position, and once in position, selectively extend the load toward a target area. During air transport, the fly jib is automatically keep horizontal by a balance system. The rotation and extension are performed by an operator using a remote radio control system. 
     In accordance with an embodiment, a fly jib for a crane having a load block includes a variable length beam having a load connection end and an opposite end. A rotation mechanism is connected to the variable length beam, the rotation mechanism being connectable to the load block so that the rotational mechanism can selectively rotate the variable length beam with respect to the load block. A balance mechanism is connected to the variable length beam, the balance mechanism keeps the variable length beam in a balanced horizontal position. 
     In accordance with another embodiment, the variable length beam includes a main beam, a load beam connected to the main beam, and a telescoping beam, the telescoping beam received by and selectively extendable from the load beam. 
     In accordance with another embodiment, the load beam is selectively positionable to an outwardly extended position co-linear with the main beam, and to a folded back position parallel to the main beam. 
     In accordance with another embodiment, the rotation mechanism includes a plurality of support arms which are connectable to the load block. A bearing rotationally connects the support arms to the main beam so that the main beam can be rotated with respect to the support arms. 
     In accordance with another embodiment, the plurality of support arms are each connected to the bearing by two bolts. One of the bolt is removable so that the support arm can be placed in a folded storage position. 
     In accordance with another embodiment, the balance mechanism includes a movable counterweight which is connected to the main beam, wherein the counterweight is selectively longitudinally positionable along the main beam by a chain drive mechanism. A sensor is connected to the main beam, the sensor sensing when the main beam is not horizontal and providing a signal to the chain drive mechanism, the signal causing the chain drive mechanism to move the counterweight until the main beam is horizontal. 
     In accordance with another embodiment, the chain drive mechanism includes a chain which is connected to the counterweight. During positioning of the counterweight by the chain drive mechanism, the chain is always in tension. 
     In accordance with another embodiment, the fly jib is connectable to a load. The counterweight has a retracted position wherein the counterweight resides substantially below the rotation mechanism. The retracted position being used when the fly jib is disconnected from the load. 
     Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the fly jib and method of use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a reduced side elevation view of a fly jib being used to place a load; 
         FIG. 2  is a reduced side elevation view of the fly jib being extended to place the load; 
         FIG. 3  is another reduced side elevation view of the fly jib being used to place a load; 
         FIG. 4  is a top plan view of the fly jib; 
         FIG. 5  is a side elevation view of the fly jib; 
         FIG. 6  is a side elevation view of the fly jib in an unbalanced state; 
         FIG. 7  is side elevation view of the fly jib supporting a load; 
         FIG. 8  is a side elevation view of the fly jib with the load extended; 
         FIG. 9  is a top plan view of the fly jib in an angular position; 
         FIG. 10  is a top plan view of the fly jib in another angular position; 
         FIG. 11  is a side elevation view of the fly jib with a counterweight moved to a retracted position; 
         FIG. 12  is a top plan view of the fly jib in one angular position; 
         FIG. 13  is a top plan view of the fly jib rotated to another angular position; 
         FIG. 14  is an enlarged view of area  14  of  FIG. 5 ; 
         FIG. 15  is an enlarged end elevation view of  FIG. 14 ; 
         FIG. 16  is an enlarged view of area  16  of  FIG. 5 ; 
         FIG. 17  is an enlarged view of area  17  of  FIG. 16 ; 
         FIG. 18  is a top plan view of a variable length beam with a load beam in a folded storage position; 
         FIG. 19  is a top plan view of four support arms in a ready for use position; and, 
         FIG. 20  is a top plan view of the four support arms in a folded storage position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to  FIGS. 1-3 , there are illustrated reduced side elevation views of a fly jib  20  in accordance with the present invention being used to place a load  500  inside a building  700  having a target area  702 . Fly jib  20  cooperates with a ground crane  600  having a load block  602 . Fly jib  20  is connected to load block  602  by four rope slings  604 . Load block  602  and slings  604  allow fly jib  20  to be positioned for load pick-up and movements to required locations inside building or cavities. Fly jib  20  is held horizontal by a balance mechanism which includes a travelling counterweight which balances the weight of the load that is being lifted. Fly jib  20  stays in the horizontal position as it is moves and operates.  FIGS. 1 and 2  show ground crane  600  positioning load  500  inside a building  700 . In  FIG. 1  fly jib  20  is maneuvered into position so that load  500  is ready to enter building  700  and be placed on target area  702 . In  FIG. 2  the operator with radio remote control extends fly jib  20  and load  500  into building  700  so that fly jib  20  is outside building  700  and load  500  is inside building  700  over target area  702 . As fly jib  20  extends the counterweight will automatically move rearward to maintain horizontal balance of the system. When load  500  is lowered and is supported by the ground at target area  702 , the counterweight will retract inward until load connection is free and can be released. Fly jib  20  is then retracted by operator to the outside of the building. A very common usage for fly jib  20  is in multi-story buildings as is depicted in  FIG. 3  wherein materials need to be placed into the rooms of the building during construction. Load  500  is extended into the building and released as in  FIGS. 1 and 2 . It is noted that entrance into building  700  can also be assisted by lowering the boom of crane  600  and raising the crane hoist. If any rotation of fly jib  20  takes place the operator can rotate fly jib  20  to a desired angular position as required. 
     Now referring to  FIGS. 4 and 5 , there are illustrated top plan and side elevation views respectively of fly jib  20 . Fly jib  20  includes a variable length beam  22  which has a load connection end  24  and an opposite end  26 . That is, the length of variable length beam  22  is selectively remote controllable by an operator so that load  500  can be moved over target area  702  (refer to  FIGS. 1 and 2 ). Variable length beam  22  includes a main beam  28 , a load beam  30  connected to main beam  28 , and a telescoping beam  32  which is received by and is selectively extendable from load beam  30 . As is shown in  FIG. 5  cutaway view, the extension of telescoping beam  32  is effected by an hydraulic cylinder  34 . Telescoping beam  32  extends or retracts per operator control. Load  500  is attached to the end of telescoping beam  32 , which can be extended and retracted under load. 
     A rotation mechanism  36  (also refer to  FIGS. 16 and 17 ) is connected to variable length beam  22 . Rotation mechanism  36  is connectable to load block  602  of crane  600  so that rotational mechanism  36  can selectively rotate variable length beam  22  with respect to load block  602  (as is indicated by the rotational arrows). Rotation mechanism  36  includes a plurality of support arms  38  which are connectable by rope slings  604  to load block  602 . A disc bearing  40  (also refer to  FIG. 16 ) rotationally connects support arms  38  to main beam  28  so that main beam  28  can be rotated with respect to support arms  38 . The rotation of main beam  28  is remotely controlled by an operator. 
     A balance mechanism  42  is connected to variable length beam  22 . Balance mechanism  42  keeps variable length beam  22  in a horizontal position (attitude). Balance mechanism  42  includes a movable counterweight  44  which is connected to main beam  28 , wherein counterweight  44  is selectively longitudinally positionable along main beam  28  by a chain drive mechanism  46  (also refer to  FIGS. 14 and 15 ). A sensor  48  is connected to main beam  28 . Sensor  48  senses when main beam  28  is not horizontal and provides a signal to chain drive mechanism  46 , the signal causing chain drive mechanism  46  to move counterweight  44  until main beam  28  is horizontal. The position of counterweight  44  varies as a function of the weight of load  500 . 
     A power unit  49  is located near opposite end  26  of beam  22 , and provides power for the extension of telescoping beam  32 , the positioning of counterweight  44 , and the rotation of fly jib  20 . In an embodiment, power unit  49  is a self contained diesel power source which consists of engine, hydraulic pump, radio controlled hydraulic valving, oil reservoir and support structure. Storage rotation of variable length beam  22  as shown in  FIG. 18 , and support arms  38  as shown in  FIGS. 19 and 20  is manually powered by an operator. 
       FIG. 6  is a side elevation view of fly jib  20  in an unbalanced state. Such a state can occur for many reasons, one of which being a malfunction in balance mechanism  42 . Chain drive mechanism  46  includes a chain  50  which is connected to and effects the movement of counterweight  44 . Chain  50  is driven by two toothed sprockets  52 . During positioning of counterweight  44  by chain drive mechanism  46 , chain  50  is always in tension T. In other words, by using a chain drive system for the long extensive travel of counterweight  44 , there is no problem with compression which would cause dangerous buckling if an hydraulic cylinder were used. In the shown position, balance mechanism  42  will cause counterweight  44  to move to the left until a horizontal orientation is attained, such as in  FIG. 7 . It is further noted that a chain drive system permits more counterweight  44  travel than would an hydraulic cylinder positioning system. As shown, balance mechanism  42  would cause counterweight  44  to move to the left to balance variable length beam  22 . 
       FIGS. 7 and 8  are side elevation views of fly jib  20  supporting a load  500 , and with load  500  extended respectively. Balance mechanism  42  via counterweight  44  keeps main beam  28  (and therefore entire variable length beam  22 ) horizontally oriented. The balancing is automatically controlled via a signal from sensor  48 . It is noted that balance mechanism  42  can also be remotely controlled by an operator. This feature is useful to approximately position counterweight  44  before picking up a load. Then, the automatic balancing system will take over. Counterweight  44  travel is signaled from sensor  48  on main beam  28 . A hydraulic motor with brake rotates a chain sprocket  52  which in turn moves chain  50  which is attached to counterweight  44 , causing counterweight  44  to longitudinally travel along main beam  28  until main beam  28  is horizontal as sensed by sensor  48 . In  FIG. 8  telescoping beam  32  is outwardly extended. As such, balancing system  42  automatically causes counterweight  44  to move toward opposite end  26  to maintain a horizontal orientation of main beam  28 . 
       FIG. 9  is a top plan view of fly jib  20  in an angular position, and  FIG. 10  is a top plan view of the fly jib  20  in another angular position. Under operator control, rotation mechanism  36  causes variable length beam  22  to rotate (counterclockwise as shown) with respect to load block  602 . In the fashion, rotation mechanism  36  can be used to rotate variable length beam  22  and therefore load  500  to any desired angular position. 
       FIG. 11  is a side elevation view of fly jib  20  with counterweight  44  moved to a retracted position. The retracted position of counterweight  44  is used to disconnect fly jib  20  from load  500 . In the retracted position, counterweight  44  resides substantially below rotation mechanism  36  (i.e. closest to load  500 ). As such tension in the cables  502  supporting load  500  is minimized or eliminated. The operator places counterweight  44  in the retracted position. 
       FIG. 12  is a top plan view of fly jib  20  in one angular position, and  FIG. 13  is a top plan view of fly jib  20  rotated to another angular position. In  FIG. 12  fly jib is positioned outside a window  704  of a building  700 . An operator then uses rotation mechanism  36  to rotate variable length beam  22  in the direction of the arrow so that load  500  is aligned with window  700 . The rotation is remotely controlled by the operator, and is much safer than using long poles from window  704  to rotate the jib. Also, it is noted that load block  602  is free to rotate in accordance with OSHA requirements. As such, rotation mechanism  36  can be utilized to compensate for load block  602  rotation (such as because of wind).  FIG. 13  shows variable length beam  22  rotated so load  500  is ready to enter window  704 . Once aligned, telescoping beam  32  is extended so that load  500  moves into window  704  so that load  500  is positioned above target area  702 . Load  500  is then lowered onto target area  702 , and disconnected by first moving counterweight  44  to the retracted position of  FIG. 11 . Note that during the extension, counterweight  44  automatically moves away from load  500  to keep the horizontal balance. 
       FIG. 14  is an enlarged view of area  14  of  FIG. 5 , and  FIG. 15  is an enlarged end elevation view of  FIG. 14  showing chain drive mechanism  46  which is part of balance mechanism  42  (refer to  FIGS. 4 and 5 . Travelling counterweight  44  is connected to toothed drive sprocket  52  by chain  50 . A signal from sensor  48  (refer to  FIGS. 4 and 5 ) causes chain drive mechanism  46  to move counterweight  44  to a location along the underside of main beam  28  so that any load  500  is balanced and main beam  28  is horizontal. A motor  54  and spring break which holds counterweight  44  at the proper location are also part of chain drive mechanism  46 . 
       FIG. 16  is an enlarged view of area  16  of  FIG. 5 , and  FIG. 17  is an enlarged view of area  17  of  FIG. 16  showing rotation mechanism  36 . Rotation mechanism  36  includes a motor  60  and brake with geared pinion which drive a disc bearing (geared platform bearing)  62 . Disc bearing  62  is connected between support arms  38  and main beam  28  so that main beam  28  can be rotated with respect to support arms  38 . Disc bearing  62  includes a plate  63  to which support arms  38  are connected. Rotation mechanism  36  is remotely controlled and gives the operator the ability to rotate jib  20  as it delivers a load  500  into a building  700  etc (refer to  FIGS. 12 and 13  and the associated discussion). If fly jib  20  did not have this rotational capability it would be difficult and dangerous to rotate the jib, which has to be accomplished by personnel using 10 feet long poles that will kick the jib to rotate and then stop the rotation for entry into the room. Via support arms  38 , rotation mechanism  36  is connected to load block  602  by four rope slings  604  (refer also to  FIGS. 4 and 5 ). As mentioned previously crane load block  602  rotates freely as it must to conform with ANSI code. This rotation can be counteracted by jib rotational mechanism  36 . 
       FIG. 18  is a top plan view of variable length beam  22  with load beam  30  in a folded storage position. Load beam  30  is selectively positionable to an outwardly extended position co-linear with main beam  28  (refer to  FIGS. 4 and 5 ), and to a folded back position parallel to main beam  28  as is depicted in  FIG. 18 . In  FIG. 18 , rotation mechanism  36  is not shown for clarity. To effect the folded back position, one of the two vertical pins  70  which normally connect load beam  30  to main beam  28  (also refer to  FIGS. 4 and 5 ) is removed and load beam  30  is rotated about the remaining pin  70 . The folded back position of load beam  30  is useful to create a smaller package for shipping in a standard container or storage. 
       FIG. 19  is a top plan view of in which the plurality (four) support arms  38  of rotation mechanism  36  are in a ready for use position, and  FIG. 20  is a top plan view of the four support arms  38  in a folded storage position. In this embodiment, the plurality of support arms  38  are each connected to bearing  62  of rotation mechanism  36  by two bolts  72 . The connection is actually to plate  63 . As with load bearing above (refer to  FIG. 18  and the associated discussion) one bolt  72  is removable so that support arm  38  can be placed in a folded storage position which is illustrated in  FIG. 20 . 
     In terms of use, a method for placing a load includes, (refer to  FIGS. 1-20 ) 
     (a) providing a load  500 ; 
     (b) providing a target area  702  for load  500 ; 
     (c) providing a crane  600  having a load block  602 ; 
     (d) providing a fly jib  20  for crane  600 , fly jib  20  including;
         a variable length beam  22  having a load connection end  24  and an opposite end  26 , variable length beam  22  including a main beam  28 , a load beam  30  connected to main beam  28 , and a telescoping beam  32 , telescoping beam  32  received by selectively extendable from load beam  32 ;   a rotation mechanism  36  connected to variable length beam  22 , rotation mechanism  36  connectable to load block  602  so that rotational mechanism  36  can selectively rotate variable length beam  22  with respect to load block  602 ;   a balance mechanism  42  connected to variable length beam  22 , balance mechanism  42  for keeping variable length beam  22  in a horizontal position;       

     (e) connecting rotation mechanism  36  to load block  602  of crane  600 ; 
     (f) connecting load  500  to load connection end  24  of variable length beam  22 ; 
     (g) using crane  600  to lift variable length beam  22  wherein balance mechanism  42  keeps variable length beam  22  in a horizontal position; 
     (h) using crane  600  to move variable length beam  22  toward target area  702 ; 
     (i) using rotation mechanism  36  to rotate variable length beam  22  to a desired angular position; 
     (j) causing variable length beam  22  to extend and place load  500  above target area  702 ; 
     (k) lowering variable length beam  22  until load  500  rests upon target area  702 ; and, 
     (l) disconnecting load  500  from variable length beam  22 . 
     The method further including: 
     in (d), variable length beam  22  including a main beam  28 , 
     in (d), balance mechanism  42  including a movable counterweight  44  connected to main beam  28 , wherein counterweight  44  is selectively longitudinally positionable along main beam  28  by a chain drive mechanism  46 , and a sensor  48  connected to main beam  28 , sensor  48  sensing when main beam  28  is not horizontal and providing a signal to chain drive mechanism  46 ; and, 
     in (g), the signal causing chain drive mechanism  46  to move counterweight  44  until main beam  28  is horizontal. 
     The method further including: 
     in (d), chain drive mechanism  46  including a chain  50  which is connected to counterweight  44 ; and, 
     in (g) during positioning of counterweight  44  by chain drive mechanism  46 , chain  50  always being in tension. 
     The method further including: 
     after (k) and before (l), causing counterweight  44  to assume a retracted position substantially below rotation mechanism  36 . 
     The method further including: 
     in (i), rotation mechanism  36  being remotely controlled. 
     The method further including: 
     in (j), the extending of variable length beam  22  being remotely controlled. 
     The method further including: 
     in (d), load beam  30  selectively positionable to an outwardly extended position co-linear with main beam, and to a folded back position parallel to main beam  28 ; and, 
     after (l), for storage placing load beam  32  in the folded back position. 
     The embodiments of the fly jib and method of use described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims. Further, nothing in the above-provided discussions of the fly jib and method should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is defined by the appended claims.