POWER TRANSFER SYSTEM OF CIRCULATING TYPE GANTRY CRANE

Abstract: A power transfer system of a circulating type gantry crane including a spreader, a hook which is coupled to the spreader, a hoist which is connected to the hook by a steel cable to elevate the hook, and a trolley which moves along a boom in a state of being coupled to the spreader, the power transfer system characterized in that the spreader is selectively separated from and coupled to the trolley or the hook, and comprises first latches for coupling to the hook, second latches for coupling to the trolley, and a power connection portion for operating the first and second latches with power received from a power source, the hook has locking holes for introducing the first latches on the spreader, and a power transfer portion which is connected to the power connection portion and an external power source to provide power to the power connection portion, and the trolley has locking holes into which the second latches on the spreader are inserted and coupled. In this power transfer system of a circulating type gantry crane having such a configuration, power is smoothly carried from a hook to a spreader while separation and coupling between a spreader and a hook and between the spreader and the trolley is simple, so that stable and safe loading and unloading can be achieved.

Description: POWER TRANSFER SYSTEM OF CIRCULATING TYPE GANTRY CRANE Technical Field The present invention relates to a gantry crane for moving containers for freight transportation or for carrying heavy materials such as steel, and more particularly, to a power transfer system of a circulating type gantry crane for transferring power to trolleys while circulating around a boom of the circulating type gantry crane Background Art Conventional gantry cranes for loading and unloading containers are designed so that a hoist, a hook a trolley and a spreader move along a boom horizontally installed on a main tower pillar, in a state of being coupled to each other or connected to a steel cable In particular, trolleys are constructed so that they reciprocate between the location of a container to be carried and a loading location, and receive power from a power source via a drooping electric cable In the horizontal circulating type gantry crane of Korean Patent No 134235 or the vertical circulating type gantry crane of Korean Patent No 143699, trolleys circulate along a track in a state of being separated from a hoist, so that it is difficult to supply power to the trolleys by connecting electric cables to the trolleys However, in the circulating type gantry cranes, hoists corresponding to the trolleys of a conventional crane move slowly and only have to traverse a section of the length of the boom so that they move a short distance Therefore, the trolleys can be provided with power by connecting electric cables to the hoists Disclosure of the Invention An objective of the present invention is to provide a power transfer system of a circulating type gantry crane which is constructed so that containers are moved horizontally by trolleys and spreaders which are not connected to power cables, and the containers are lifted or laid down by power provided via hooks when spreaders have been coupled to the hooks, so that the loading/unloading speed and efficiency of containers are high. The above objective of the present invention is achieved by a power transfer system of a circulating type gantry crane including a spreader, a hook which is coupled to the spreader, a hoist which is connected to the hook by a steel cable to elevate the hook and a trolley which moves along a boom in a state of being coupled to the spreader, the power transfer system characterized in that the spreader is selectively separated from and coupled to the trolley or the hook, and comprises first latches for coupling to the hook, second latches for coupling to the trolley and a power connection portion for operating the first and second latches with power received from a power source, the hook has locking holes for introducing the first latches on the spreader, and a power transfer portion which is connected to the power connection portion and an external power source to provide power to the power connection portion, and the trolley has locking holes into which the second latches on the spreader are inserted and coupled First and second slits connected to the internal space of the spreader are formed on the upper surface of the spreader, first locking plates are formed on the bottom surface of the hook and inserted into the first slits and coupled to the spreader and second locking plates are formed on the bottom surface of the trolley and inserted into the second slits and coupled to the spreader A guide member for guiding the hook as it descends is fixed to the lateral side of each of the first latches of the spreader Each of the first and second latches is comprised of a support portion fixed onto the spreader, and a rotating portion which rotates over the support portion, a motor is installed within the spreader to rotate the rotating portion, and the driving shaft of the motor and the rotating portion are internally connected to each other such that the rotating portion is rotated by the driving of the motor At least two through holes are formed on the first and second locking plates, respectively, a support member having a pin insertion hole formed therein is fixed under each of the slits within the internal space of the spreader so that the first locking plate is inserted into the first slit and coupled thereto, and the second locking plate is inserted into the second slit and coupled thereto, a pin penetrates the through holes and the pin insertion hole in a state where the first and second locking plates are inserted into the slits, and insertion and separation of the pin are controlled by a motor which moves the pin lengthwise Brief Description of the Drawings FIGS 1 to 3 are conceptual views for schematically illustrating the entire structure and operation of a gantry crane to which a power transfer system according to an embodiment of the present invention is applied, FIG 4 shows a spreader, a hook and a trolley in a power transfer system of a circulating type gantry crane according to an embodiment of the present invention, FIG 5 is an exploded perspective view for illustrating the coupling relationship between a hook and a spreader in a power transfer system of a circulating type gantry crane according to an embodiment of the present invention, FIG 6 is a cross-sectional view illustrating a way of coupling a locking plate to a spreader, in a power transfer system of a circulating type gantry crane according to an embodiment of the present invention, FIG 7 is a view for explaining the principle of operation of a latch in a power transfer system of a circulating type gantry crane according to an embodiment of the present invention, FIG 8 is an exploded perspective view for illustrating the coupling relationship between a trolley and a spreader in a power transfer system of a circulating type gantry crane according to an embodiment of the present invention, and FIG 9 is a perspective view schematically illustrating a locking hole formed in the trolley of FIG 8 Best mode for carrying out the Invention Referring to FIG 1 , a gantry crane according to the present invention is constructed so that a plurality of trolleys 50 move along a boom 100 Any of the horizontal circulating type booms and the vertical circulating type booms disclosed in the applications previously filed by the present applicant can be used as a boom along which the trolleys 50 circulate Two hoists 40 are installed on the boom 100 One of the two hoists 40 is located on the side of the land, and the other hoist is located on the side of the sea These hoists 40 can move in the directions indicated by arrows a as necessary A hook 30 is connected to each of the hoists 40 via a steel cable 114 The hook 30 elevates a container 10 by being lifted by the steel cable 114 in a state of being coupled to a spreader 20 which is directly combined with the container 10 As described later, the hook 30 is coupled to the spreader 20 to supply external power to the spreader 20 and control the position of an arm 21 of FIG 5, operate a first latch 22 or second latch 24 of FIG 5, or reciprocate a pin 82 of FIG 6 The spreader 20 ascends with the container 10, reaches the trolley 50, and is coupled to the trolley 50 At this time, the hook 30 is separated form the spreader 20, and consequently the container 10 is moved horizontally by the trolley 50 in a state of being coupled to the spreader 20 FIGS 2 and 3 show loading of a container using a power transfer system of a circulating type gantry crane according to an embodiment of the present invention FIG 2 shows a loading operation in a state where a trolley 50 enters under the hoist 40 waiting on the side of the land FIG 3 shows a loading operation in a state where the trolley 50 with the container 10 enters under the hoist waiting on the side of the sea For convenience of explanation, several hoists 40 are shown, but actually there are only two hoists, one on the land side of the boom and one on the sea side of the boom First, referring to FIG 2, a trolley 50 and a spreader 20 coupled to the bottom surface of the trolley, moving along a boom 100 in a direction indicated by arrow b, are held under a land-side hoist 40 Here, the land-side hoist 40 was positioned in advance and waits directly over a container 10 to be loaded When the trolley 50 is placed under the hoist 40, the hook 30 descends from the hoist 40, passes through the trolley 50, and is coupled to the spreader 20 At this time, a power transfer portion 36 (FIG 5) of the hook 30 is connected to a power connection portion 26 (FIG 5) of the spreader 20, so that external power is supplied to the spreader via the hook During this time, the trolley 50 is separated from the spreader 20 A coupling means for the hook 30 and the spreader 20 will be described later The hook 30 descends to the container 10 while coupled to the spreader 20 so that the spreader 20 is coupled to the container 10 When the container 10 is coupled to the spreader 20, the hook 30 ascends again When the spreader 20 reaches the trolley 50, they are re- coupled by a power transfer system of the present invention to be described later, and the hook 30 is separated from the spreader 20 Thereafter, the hook 30 separated from the spreader 20 continuously ascends to a position over the trolley 50 The trolley 50 moves over a loading/unloading position in a direction indicated by arrow c with the spreader 20 and the container 10 suspended from it As shown in FIG 3, the trolley 50 moves in a direction indicated by arrow c and enters under the sea-side hoist 40 The sea-side hoist 40 is positioned in advance and waits directly over a location on which the container 10 is to be loaded When the trolley 50 is placed under the hoist 40, the hook 30 descends from the hoist 40 and is coupled to the spreader 20 At this time, it is natural that the trolley 50 is separated from the spreader 20 When the hook 30 descends and the container 10 reaches a loading/unloading location, the container 10 is separated from the spreader 20 In this way, the loading of containers is carried out A method of separating the container 10 from the spreader 20 will be described later After the container 10 is loaded, the spreader 20 ascends together with the hook 30 and is re-coupled to the trolley 50 while being separated from the hook 30 After the spreader 20 is re-coupled to the trolley 50 as described above, it moves to the land along the boom 100, and then another waiting container can be moved in the same manner As described above, a trolley, a spreader and a hook are constructed so that they move rapidly along a boom while alternately repeating combination and separation These combination and separation stages are performed in the air, so that stability to prevent falls must be ensured In this embodiment, two types of coupling devices are provided to achieve complete and secure combination between a spreader and a hook or between a spreader and a trolley, as described later FIG 4 shows a hoist, a hook, a trolley and a spreader installed on a boom of a circulating type gantry crane employing a power transfer system according to an embodiment of the present invention As shown in FIG 4, a boom 100 provides an internal space in the center, and a hoist 40 is installed with the internal space A hook 30 is connected to the bottom surface of the hoist 40 so that it ascends and descends suspended by a steel cable 114 Also, the center of a trolley 50 installed under the hoist 40 is hollow, as shown in FIG 8, so that the hook 30 can pass through the trolley 50 while ascending The length of a spreader 20, which is selectively coupled to the hook 30 and the trolley 50 can be controlled according to the length of a container 10, and a power connection portion 26 and first and second latches 22 and 24 are formed on the upper surface of the spreader 20 The power connection portion 26 is a type of terminal which is connected to the power transfer portion 36 of the hook 30 to receive electricity Also, the first latch 22 is coupled to a locking hole 32 formed on the bottom surface of the hook 30 FIG 5 shows the hook 30, the spreader 20 and the container 10 to explain the power transfer system of a circulating type gantry crane according to an embodiment of the present invention As shown in FIG 5, grooves 12 are formed at the four corners of the upper surface of the container 10, and latches (not shown) installed on the bottom surface of the spreader 20 are coupled to the grooves 12 by being inserted thereinto, or separated therefrom This form of combination and separation between a container and a spreader is the same as in the prior art On the upper surface of the spreader 20 are installed four first latches 22 which are inserted into and coupled to the locking holes 32 of the hook 30, four second latches 24 which are coupled to the locking holes 54 (FIG 9) of the trolley 50, and a plurality of power connection portions 26 which are connected to the power transfer portions 36 of the hook 30 to receive external power The power transfer portions 36 of the hook 30 are terminals which receive external power A locking guide plate 23 is fixed on the outside of each of the first latches 22, and guides each of the first latches 22 on the spreader to be smoothly inserted into a corresponding locking hole 32 of the hook 30 when the hook 30 is coupled to the spreader 20 Each of the first and second latches 22 and 24 is made up of a support portion 71 and a rotating portion 73 The support portion 71 is fixed on the upper surface of the spreader 20, and the rotating portion 73 rotates a certain angle on the support portion 71 The rotation of the rotating portion 73 is controlled by a motor 86 which is driven by external power as shown in FIG 7 Accordingly, as the rotating portions 73 rotate a certain angle in a state where the first latches 22 are inserted into the locking holes 32 of the hook 30, the hook 30 and the spreader 20 are combined with each other Undoubtedly, when the hook 30 is separated from the spreader 20, the rotating portions 73 are restored to their original locations Preferably, the rotation angle of each of the rotating portions 73 is 90 degrees Meanwhile, arms 21 provided on both sides of the spreader 20 advance and retreat with power received from the power connection portions 26, and thus their lengths are adjusted to the length of the container 10 In order to achieve this, a motor (not shown) for moving the arms 21 is provided within the spreader 20 A container guide plate 28 is attached to each edge of the arm 21 of the spreader 20 The container guide plate 28 guides the spreader 20 against the container 10 as the spreader descends to be coupled to the container 10 Accordingly, it is preferable that each of the guide plates 28 has a lower portion that is widened The guide plates 28 are located over the spreader 20 by being pivoted in a direction indicated by arrow A after the combination with the container 10 is completed in order not to obstruct the movement of the spreader 20 The locking holes 32 formed on the bottom surface of the hook 30 are formed to face the first latches 22, and has a space in which each of the inserted rotating portions 73 can rotate That is, each of the locking holes 32 has a rectangular shape that corresponds to the cross-section shape of each of the first latches 22 so that the rotating portion 73 of each of the first latches 22 is inserted into each locking hole, and rotates 90° to be coupled thereto First locking plates 35 are vertically fixed to both sides of the bottom surface of the hook 30 and first slits 25 are formed on both sides of the upper surface of the spreader 20 to receive the locking plates 35 Each of the locking plates 35 has a hollowed central low portion so as not to hinder the horizontal movement of the arm 21 Also through holes 34 for pins 82 of FIG 6 are formed on both sides of each of the locking plates 35 to prevent the locking plates from slipping out of the slits 25 after being inserted thereinto The pins that are inserted into the through holes 34 are installed within the spreader 20, and are fit into or separated from the through holes 34 by external power similar to the rotating portions 73 That is when the hook 30 descends against the spreader 20 the first latches 22 are inserted into the locking holes 32, and the first locking plates 35 are inserted into the first slits 25 Simultaneously, the rotating portions 73 are rotated, and the pins 82 of FIG 6 are inserted into the through holes 34, whereby the hook 30 is coupled to the spreader 20 FIG 6 illustrates the principle of coupling locking plates to a spreader and separating them therefrom in a circulating type gantry crane employing a power transfer system according to an embodiment of the present invention Referring to FIG 6, a support member 85 is formed in the internal space of the spreader 20 which corresponds to a portion under the slit 25 or 27 Two bars of the support member 85 are spaced apart from each other a distance which corresponds to the thickness of the locking plate 35 or 57, and each of them has a pin insertion hole 84 The pin insertion hole 84 is matched to the through hole 34 or 53 of the locking plate and penetrated by the pin 82 A motor 81 is installed on one side of the support member 85 A direct current motor that changes the direction of rotation according to the direction of current is preferred as the motor 81 A pinion is fixed onto the driving shaft of the motor 81 , and a rack 83 which interlocks with the pinon, is horizontally placed over the driving shaft The rack 83 is combined with the pin 82 Therefore, when the motor 81 is driven the rack 83 is reciprocated by the rotation of the pinon, whereby the pin 82 is inserted into or separated from the pin insertion hole 84 It is natural that power supplied to the motor 81 is received from the power connection portion 26 of FIG 5 FIG 7 shows a means for rotating the rotating portion against the support portion Referring to FIG 7, a support portion 71 is fixed onto the upper surface of the spreader 20, and an extended shaft 87 that is rotated by a motor 86 is fixed to a rotating portion 73 installed on the support portion 71 The extended shaft 87 is connected to the driving shaft of the motor 86, and vertically penetrates the support portion 71 so that its end is coupled to the rotating portion 73 Accordingly, when the driving shaft of the motor 86 is rotated through a predetermined angle, the rotating portion 73 is rotated against the support portion 71 within the locking hole 32 or 54 whereby the hook 30 or the trolley 50 is coupled to the spreader 20 When the rotating portion 73 is restored to its original location by the control of the motor 86, the latches 22 and 24 can be separated from the locking holes 32 and 54, respectively FIG 8 is an exploded perspective view for illustrating the coupling relationship between the trolley 50 and the spreader 20 As shown in FIG 8, four legs 51 are vertically fixed on the bottom surface of the trolley 50 A locking hole 54 of FIG 9 for each of the second latches 24 is formed on the bottom surface of each of the legs 51 The function and shape of the locking holes 54 are the same as those of the locking holes 32 The second latches 24 are internally connected to the power connection portion 26, and perform the same function and operation as the first latches 22 described with reference to FIG 7 Accordingly, when the second latches 24 are inserted into the locking holes 54 as the hook 30 coupled to the spreader 20 ascends, the rotating portion of each of the second latches 24 is rotated, and thus the second latches 24 are locked inside each of the locking holes 54 Similar to the hook 30, second locking plates 57 are installed on both sides of the bottom surface of the trolley 50, and second slits 27 for the second locking plates 57 are formed on the spreader 20 Through holes 53 capable of receiving the pins 82 are formed on each of the second locking plates 57 Coupling and separation between the spreader 20 and the second locking plates 57 are achieved as described above with reference to FIG 6 One of the first and second locking plates 35 and 57 must be coupled to a spreader For example, the second locking plate 57 must be coupled to the spreader 20 before the first locking plate 35 is separated from the spreader 20 Likewise the first locking plate 35 must be coupled to the spreader 20 before the second locking plate 57 is separated from the spreader 20 Therefore, the above-described separations and couplings are achieved not simultaneously but sequentially FIG 9 shows a locking hole formed in a trolley As shown in FIG 9, a locking hole 54 is formed on the bottom surface of each of the legs 51 of the trolley 50 A second latch 24 is inserted and locked into the locking hole 54 When moving cargo using the coupling and separation mechanism described above, separation and coupling between the trolley 50 and the spreader 20 and between the hook 30 and the spreader 20 are repeated That is, when the trolley 50 with the spreader 20 suspended from it arrives directly over a waiting container, the hook 30 descends, passes through the trolley 50, and is coupled to the spreader 20, as described above Next, the second latches 24 on the spreader 20 are restored to their original locations, and simultaneously, the second locking plates 57 are separated from the spreader 20 Thereafter, when the hook 30 coupled to the spreader 20 descends to the container 10, and thus the spreader 20 is coupled to the container 10, the container guide plates 28 are folded upward, the second latches 24 of the spreader 20 are inserted into the locking holes 54 as the hook 30 ascends, and the second locking plates 57 are inserted into the second slits 27 and coupled thereto by pins In this way, the spreader 20 and the trolley 50 are locked together Following this, the first locking plates 35 of the hook 30 are separated from the first slits 25 of the spreader 20, and the first latches 22 are separated from the locking holes 32, whereby the hook 30 is separated from the spreader 20 Only the trolley 50, the spreader 20 and the container 10 move to a position over a loading location along the boom The container 10 is loaded at the loading location by repeating the above-described operations The drawings and specification, which are just an example of the present invention, are provided not to restrict the meaning or the scope of the present invention defined by the accompanying claims, but to explain the present invention The mechanism in which a trolley and a spreader move along a boom through separation or combination between the trolley and the spreader and between a hook and the spreader, must be construed as being encompassed within the scope of the present invention Industrial Applicability In a power transfer system of a circulating type gantry crane according to the present invention as described above, power is smoothly carried from a hook to a spreader, even while separation and coupling between a spreader and a hook and between the spreader and a trolley are repeated Thus, for example, a spreader can pick up a container in a state of being coupled to a hook Also, the mechanism of separation and coupling between the spreader and the hook and between the spreader and the trolley is simple, so that stable and safe loading and unloading can be achieved

Claims: What is claimed is 1 A power transfer system of a circulating type gantry crane including a spreader, a hook which is coupled to the spreader, a hoist which is connected to the hook by a steel cable to elevate the hook, and a trolley which moves along a boom in a state of being coupled to the spreader, the power transfer system characterized in that the spreader is selectively separated from and coupled to the trolley or the hook, and comprises first latches 22 for coupling to the hook 30, second latches 24 for coupling to the trolley 50, and a power connection portion 26 for operating the first and second latches 22 and 24 with power received from a power source, the hook has locking holes 32 for introducing the first latches 22 on the spreader 20, and a power transfer portion 36 which is connected to the power connection portion 26 and an external power source to provide power to the power connection portion 26, and the trolley 50 has locking holes 54 into which the second latches 24 on the spreader 20 are inserted and coupled 2 The power transfer system of a circulating type gantry crane of claim 1 , wherein first and second slits connected to the internal space of the spreader 20 are formed on the upper surface of the spreader 20, first locking plates 35 are formed on the bottom surface of the hook 30 and inserted into the first slits 25 and coupled to the spreader 20, and second locking plates 57 are formed on the bottom surface of the trolley 50 and inserted into the second slits 27 and coupled to the spreader 20 3 The power transfer system of a circulating type gantry crane of claim 1 , wherein a guide member for guiding the hook 30 as it descends is fixed to the lateral side of each of the first latches 22 of the spreader 20 The power transfer system of a circulating type gantry crane of claim 1 , wherein each of the first and second latches 22 and 24 is comprised of a support portion 71 fixed onto the spreader 20, and a rotating portion 73 which rotates over the support portion 71 , a motor 86 is installed within the spreader 20 to rotate the rotating portion 73, and the driving shaft of the motor 86 and the rotating portion 73 are internally connected to each other such that the rotating portion 73 is rotated by the driving of the motor 86 5 The power transfer system of a circulating type gantry crane of claim 2, wherein at least two through holes 34 and 53 are formed on the first and second locking plates 35 and 57 respectively, a support member 85 having a pin insertion hole 84 formed therein is fixed under each of the slits 25 and 27 within the internal space of the spreader so that the first locking plate 35 is inserted into the first slit 25 and coupled thereto, and the second locking plate 57 is inserted into the second slit 27 and coupled thereto, a pin 82 penetrates the through holes 34 and 53 and the pin insertion hole 84 in a state where the first and second locking plates 35 and 57 are inserted into the slits 25 and 27, and insertion and separation of the pin 82 are controlled by a motor 81 which moves the pin 82 lengthwise

Inventors: HAN MAN YOP, HAN, MAN, YOP
Applicants: HAN MAN YOP, HAN, MAN, YOP
Application year: 2000
Main classification: B66C19
IPC codes: B66C1, B66C13, B66C19