Elevating conveyance device

The present invention proposes an elevating conveyance device with improved versatility which can be utilized for transferring an automobile body in an automobile assembly line, etc., and according to a first aspect of the invention, the elevating conveyance device includes a multistage extensible column, a transfer means, and an extending and contracting drive mechanism, where the multistage extensible column includes a fixed column portion, one or more mid-stage elevating column portions, and a final-stage elevating portion, the transfer means is provided on the final-stage elevating portion, and the extending and contracting drive mechanism includes a counter weight supported on the fixed column portion movably vertically in a range of the height of the fixed column portion, a winding transmission tool which applies the gravity of the counter weight upward to the next mid-stage elevating column portion, an elevating drive means which drives and elevates the next mid-stage elevating column portion with respect to the fixed column portion, and winding transmission tools which convert an upward movement of the mid-stage elevating column portion into an upward movement of the next mid-stage elevating column portion or final-stage elevating portion.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an elevating conveyance device which can be used for transfer, etc., of an automobile body in an automobile assembly line.

BACKGROUND OF THE INVENTION

As an elevating conveyance device which can be used for transfer, etc., of an automobile body, there is known a table-lifter type equipped with a transfer means that can advance and withdraw horizontally on an elevating base, and as described in Japanese Published Unexamined Utility Model Application No. S58-92221, a drop-lifter type equipped with a transfer means that can advance and withdraw horizontally on an elevating body movable vertically along columns. A multijoint robot type elevating conveyance device that can be used for a transfer device is also known.

The table lifter type elevating conveyance device and the multijoint robot type transfer elevating conveyance device realize a comparatively free layout and can be freely installed and used on a floor surface as long as the floor surface is rigid, however, it cannot be used out of a transfer point with a comparatively small lifting distance. In addition, in the multijoint robot type transfer elevating conveyance device, the degree of freedom of the transfer path is high, however, the facility cost remarkably increases. On the other hand, in the drop-lifter type elevating conveyance device as described in Japanese Published Unexamined Utility Model Application No. S58-92221, the lifting distance is allowed to be long, however, the upper ends of the columns must be joined to and supported by a beam on the ceiling side, so that the device cannot be easily installed on the floor and used. That is, the device is insufficient in versatility.

DETAILED DESCRIPTION OF THE INVENTION

An object of the present invention is to provide an elevating conveyance device which can solve the conventional problems described above, and an elevating conveyance device of a first aspect of the invention includes (as is shown with reference numerals of embodiments described later) a base2; a multistage extensible column1extensible vertically stood on the base2; an object support (transfer means14); and an extending and contracting drive mechanism, wherein the multistage extensible column1includes a fixed column portion3to be fixed onto the base2, one or more mid-stage elevating column portions4aand5amovable vertically with respect to this fixed column portion3, and a final-stage elevating portion6amovable vertically with respect to the mid-stage elevating column portion5a, the object support (transfer means14) is provided on the final-stage elevating portion6aof the multistage extensible column1, and the extending and contracting drive mechanism includes a counter weight20supported on the fixed column portion3of the multistage extensible column1movably vertically within a range of the height of the fixed column portion3, a winding transmission tool21awhich applies the gravity of the counter weight20upward to the next mid-stage elevating column portion4a, an elevating drive means24which drives and elevates the next mid-stage elevating column portion4awith respect to the fixed column portion3, and winding transmission tools22aand23awhich convert an upward movement of the next mid-stage elevating column portion4awith respect to the fixed column portion3into an upward movement of the next mid-stage elevating column portion5aor final-stage elevating portion6awith respect to this mid-stage elevating column portion4a.

In the elevating conveyance device of the present invention constituted as described above, even when the object support (transfer means14) to be elevated has a load cradle (running forks15aand15b) that advances and withdraws horizontally and laterally, to secure self-standing stability in the state that the multistage extensible column1extends upward and the load cradle (running forks15aand15b) supporting an object advances horizontally, the widths in the load cradle advancing and withdrawing direction of the multistage extensible column1and the base2are set to be properly wide and the base2is firmly installed and fixed onto the floor surface, whereby the elevating conveyance device can be utilized as a free-layout type self-standing elevating conveyance device similar to the conventional table lifter type or multijoint robot type elevating conveyance device, which can be freely installed and used on an arbitrary location on the floor surface. In addition, by using the multistage extensible column1, while the elevating conveyance path length (lifting distance) is allowed to be long, the multistage extensible column1is urged in the extending direction by the counter weight20and the winding transmission tools21a,22a, and23a, so that the device can elevate and convey a heavy object by the elevating drive means24that is comparatively small in capability. The counter weight20moves vertically within the range of the height of the fixed column portion3that can be made substantially equal in height to the height when the multistage extensible column1contracts to the lowest height, so that when the counter weight20reaches its upper limit position, that is, when the object support (transfer means14) is lowered to its lower limit position, the total height and the gravity of the whole device can be made low.

To carry out the present invention constituted as described above, in detail, a constitution can be employed in which the multistage extensible column1has mid-stage elevating column portions4aand4b(5aand5b) and final-stage elevating portions6aand6bon both left and right sides of one fixed column portion3, the pair of left and right final-stage elevating portions6aand6bare joined integrally by a horizontal joint member13, and the object support (transfer means14) is supported by the horizontal joint member13so that the object support (transfer means14) supports an object on one side of the fixed column portion3.

With this constitution, a comparatively wide space occupied by one fixed column portion3whose horizontal width can be made wide can be utilized as an elevating space for one large counter weight20. Therefore, in combination with stable supporting of the object support (transfer means14) by the pair of left and right mid-stage elevating column portions4aand4b(5aand5b) and the final-stage elevating portions6aand6b, the elevating conveyance device that can handle a heavy object can be constituted comparatively compactly.

A constitution can be employed in which a pair of left and right multistage extensible columns51A and51B are provided parallel so that their final-stage elevating portions6aand6bface each other, the final-stage elevating portions6aand6bof the multistage extensible columns51A and51B are joined integrally to each other by a horizontal joint member13, and the object support (transfer means14) is supported by the horizontal joint member13so that the object support (transfer means14) supports an object between the multistage extensible columns51A and51B.

In this case, a constitution can be employed in which the object support (transfer means14) has a load cradle (running forks15aand15b) that can advance and withdraw horizontally, and this load cradle (running forks15aand15b) can advance and withdraw both forward and rearward from a withdrawn position at an intermediate position of the multistage extensible columns51A and51B.

With the constitution described above having integrally-joined, parallel final-stage elevating portions6aand6b, in the state that the object support (transfer means14) supports an object between the multistage extensible columns51A and51B, no fall-down moment is applied to the multistage extensible columns51A and51B, so that the device can be easily utilized as a self-standing installation type elevating conveyance device which can handle a heavy object. In this case, by employing the constitution described above having a load cradle that can advance and withdraw, the device can be utilized as an elevating conveyance device which can convey an object from one to the other of the front and rear sides of an elevating conveyance device installation location in a plan view.

The present invention also proposes an elevating conveyance device according to a second aspect of the invention that does not use the counter weight in addition to the first aspect of the invention using the counter weight described above.

That is, the elevating conveyance device according to the second aspect of the invention includes (as is shown with the reference numerals of embodiments described later) a base2; a multistage extensible column1extensible vertically stood on the base2; an object support (transfer means14); and an extending and contracting drive mechanism, wherein the multistage extensible column1includes a fixed column portion3to be fixed onto the base2, one or more mid-stage elevating column portions4aand5amovable vertically with respect to the fixed column portion3, and a final-stage elevating portion6amovable vertically with respect to the mid-stage elevating column portion4aand5a, the object support (transfer means14) is provided on the final-stage elevating portion6aof the multistage extensible column1, and the extending and contracting drive mechanism is provided in the fixed column portions3and includes an elevating drive means120which drives and elevates the next mid-stage elevating column portion4a, pulley-wound type winding suspending chains121aand122awhich are provided in the mid-stage elevating column portions4aand5aand convert upward movement of the mid-stage elevating column portions4aand5awith respect to the previous column portion3and4ainto an upward movement of the next mid-stage elevating column portion5aor final-stage elevating portion6awith respect to the mid-stage elevating column portion4aor5a, a fluid pressure cylinder137A which urges the next mid-stage elevating column portion4aupward with respect to the fixed column portion3, and fluid pressure cylinders138A and139A which urge the next mid-stage elevating column portion5aor final-stage elevating portion6aupward with respect to the mid-stage elevating column portion4aor5a.

In the elevating conveyance device according to the second aspect of the invention described above, different from the elevating conveyance device of the first aspect of the invention described above, the weight balance is righted by urging the mid-stage elevating column portions4aand5aand the final-stage elevating portion6aby urging forces of the fluid pressure cylinders137A through139A separately without using a large and heavy balance weight, so that a heavy object can be conveyed vertically while downsizing and reduction in weight of the whole device are realized.

That is, in the multistage extensible column1constituted so that, by the pulley-wound type winding suspending chains121aand122aprovided in the fixed column portion3and the mid-stage elevating column portion4aor5a, when the mid-stage elevating column portion4aor5amoves up with respect to the previous column portions3or4a, the next mid-stage elevating column portion5aor final-stage elevating portion6ais moved upward with respect to the mid-stage elevating column portion4aor5a, a balance weight is hung on the end of the pulley-wound type winding suspending chain provided in the fixed column portion3, and if all elevating portions (excluding the object) are balanced in weight by this balance weight, for example, when two mid-stage elevating column portions are provided, assuming that the total weight of the final-stage elevating portion6ais defined as W1and the total weights of the mid-stage elevating column portions4aand5aare defined as W2and W3, the downward loading weight F to be applied in the direction of hanging the balance weight by the pulley-wound type winding suspending chain of the fixed column portion3becomes F=3W1+2W2+W3, and a large and heavy balance weight corresponding to F=3W1+2W2+W3is required, and the whole device inevitably increases in size and weight.

However, according to the second aspect of the invention, the mid-stage elevating column portions4aand5aand the final-stage elevating portion6aare urged upward by urging forces of the fluid pressure cylinders137A through139A to right the weight balance, so that the weights of the mid-stage elevating column portions4aand5aand the final-stage elevating portion6aincrease according to the weights of the fluid pressure cylinders137A through139A, however, without using a large and heavy balance weight, the loading weight to be applied to the elevating drive means120for driving and elevating the next mid-stage elevating column portion4awith respect to the fixed column portion3is greatly reduced, and accordingly, a small-sized and light-weight elevating conveyance device which can use an elevating drive means12with small capability while the device is capable of elevating and conveying a heavy object is realized. The fluid pressure cylinders137A through139A which separately urge the mid-stage elevating column portions4aand5aand the final-stage elevating portion6aupward serve as dampers when the pulley-wound type winding suspending chains121aand122aand a winding suspending chain125aused as the elevating drive means120for driving and elevating the next mid-stage elevating column portion4awith respect to the fixed column portion3are broken, so that impact drop of the mid-stage elevating column portions4aand5aand the final-stage elevating portion6acan be prevented and the safety can be improved.

To carry out the second aspect of the invention, it is allowed that cylinder main bodies137athrough139aof the fluid pressure cylinders137A through139A are attached to the previous column portions3through5a, and piston rods137bthrough139bprojecting downward from the cylinder main bodies137athrough139aso as to advance and withdraw are arranged in a direction of suspending the next mid-stage elevating column portion4aor5aor final-stage elevating portion6a.

With this constitution, it is not necessary to apply a compressive force to the piston rods137bthrough139bof the fluid pressure cylinders137A through139A which urge the mid-stage elevating column portions4aand5aand the final-stage elevating portion6aupward, respectively, so that comparatively small-diameter cylinders can be used, and this is useful for reducing the size and weight of the whole device.

In addition, a constitution can be employed in which each of the fluid pressure cylinders137A through139A generates a fixed upward urging force substantially balanced with the weight of the one mid-stage elevating column portion4aor5aor the final-stage elevating portion6athat each of the fluid pressure cylinders137A through139A directly urges.

With this constitution, the weight of all elevating portions in a state that they do not elevate and convey an object can be canceled by upward urging forces of the fluid-pressure cylinders137A through139A, and this is effective when the object is comparatively light in weight or when the weight of the object to be handled is not constant.

Further, a constitution can be employed in which the urging force of the fluid-pressure cylinder139A that urges upward the final-stage elevating portion6acan be switched to an upward urging force almost balanced with the sum (W0+W1) of the weight W1of this final-stage elevating portion6aand the weight W0of the object W loaded on the object support (transfer means14).

This constitution is preferable when the object to be handled has a fixed weight, and by employing this constitution not only when driving and elevating an empty final-stage elevating portion6aon which no object is loaded, but also when elevating and conveying the object, only by switching the urging force of the fluid pressure cylinder139A that urges the final-stage elevating portion6aupward, the whole elevating section is theoretically made weightless, and driving and elevating can always be made by a very small elevating and driving force. When a plurality of kinds of objects are handled and their weights are constant in each type, the urging force of the fluid pressure cylinder139A that urges the final-stage elevating portion6aupward is switched to an urging force preset corresponding to the weight of each object.

The elevating drive means120may include a winding suspending chain125awhich drives and elevates the next mid-stage elevating column portion4awith respect to the fixed column portion3, and a driving device127which drives the winding suspending chain125a, or it is also allowed that the fluid pressure cylinder137A that urges upward the next mid-stage elevating column portion4awith respect to the fixed column portion3can be commonly used as the elevating drive means120.

The elevating drive means120which drives and elevates the next mid-stage elevating column portion4awith respect to the fixed column portion3can be easily carried out, and the fluid pressure cylinder137A that urges upward the next mid-stage elevating column portion4awith respect to the fixed column portion3can be commonly used as the elevating drive means120, so that the number of components of the whole device can be reduced, the structure can be simplified, and further reduction in size and weight is realized.

Also in the elevating conveyance device of the second aspect of the invention, the same working effect as in the case of the first aspect of the invention can be obtained by employing the constitutions described as detailed examples of the elevating conveyance device of the first aspect of the invention.

PREFERRED EMBODIMENTS OF THE INVENTION

Next, a first embodiment of the present invention carried out as a transfer device will be described with reference to the accompanyingFIG. 1throughFIG. 3. The reference numeral1denotes a multistage extensible column, and includes a fixed column portion3stood on a base2fixed onto the floor surface with anchors or the like, a pair of left and right first mid-stage elevating column portions4aand4bsupported movably vertically on both left and right outer sides of the fixed column portion3, a pair of left and right second mid-stage elevating column portions5aand5bsupported movably vertically on the outer sides of the first mid-stage elevating column portions4aand4b, and a pair of left and right final-stage elevating portions6aand6bsupported movably vertically on the outer sides of the second mid-stage elevating column portions5aand5b. The fixed column portion3is in a rectangular column shape long in the left and right direction in a plan view.

Any elevating guide means can be used for the elevating column portions4athrough5band the final-stage elevating portions6aand6b, however, in this embodiment, the pair of left and right first mid-stage elevating column portions4aand4bare supported on the fixed column portion3movably vertically by slide guides7fixed to the side surfaces of the fixed column portion3and slide guide rails8which are fixed across the whole heights of the inner side surfaces of the first mid-stage elevating column portions4aand4band engage with the slide guides7, and the pair of left and right second mid-stage elevating column portions5aand5bare supported on the first mid-stage elevating column portions4aand4bmovably vertically by slide guides9fixed to the outer sides of the first mid-stage elevating column portions4aand4band slide guide rails10which are fixed across the whole heights of the inner side surfaces of the second mid-stage elevating column portions5aand5band engage with the slide guides9, and the pair of left and right final-stage elevating portions6aand6bare supported movably vertically on the second mid-stage elevating column portions5aand5bby slide guides11fixed to the inner side surfaces of the final-stage elevating portions6aand6band slide guide rails12which are fixed to the outer sides of the second mid-stage elevating column portions5aand5bacross the whole heights thereof.

The first mid-stage elevating column portions4aand4band the second mid-stage elevating column portions5aand5bhave the same height as that of the fixed column portion3, and when they are at the lower limit positions as shown inFIG. 1, the lower ends thereof are supported on the base2and the upper ends thereof are substantially flush with the upper end of the fixed column portion3. On the other hand, the final-stage elevating portions6aand6bhave a height substantially half of the height of the fixed column portion3and each mid-stage elevating column portion4athrough5b, and when they are at the lower limit positions, the lower ends thereof are supported on the base2.

The lower ends of the pair of left and right final-stage elevating portions6aand6bare joined integrally to each other by a horizontal joint member13on the front side of the multistage extensible column1, and at the central position in the longitudinal direction of this horizontal joint member13, a transfer means14as an object support is provided so as to project forward at the right angle from the fixed column portion3. This transfer means14includes a pair of left and right running forks15aand15bwhich advance and withdraw horizontally in conjunction with each other as a load cradle as shown inFIG. 2. Each running fork15aor15bincludes a fixed rail member17fixed on a base portion16, a mid-stage movable rail member18supported so as to advance and withdraw on the fixed rail member17, and a load receiving rail member19supported so as to advance and withdraw on the mid-stage movable rail member18, and has an advancing and withdrawing drive means (not shown). The advancing and withdrawing drive means of the running fork15a,15bis conventionally known, and the advancing and withdrawing drive means moves the mid-stage movable rail member18so as to advance and withdraw with respect to the fixed rail member17, in conjunction with the advancing or withdrawing movement of the mid-stage movable rail member18, it can advance or withdraw the load receiving rail member19in the same direction as that of the mid-stage movable rail member18. Therefore, as shown inFIG. 1AandFIG. 2A, the load receiving rail member19can be moved so as to advance and withdraw between a withdrawn position overlapping just above the fixed rail member17and an advanced position separated sideward from the region above the fixed rail member17.

The extending and contracting drive mechanism of the multistage extensible column1will be described. As shown inFIG. 3, the extending and contracting drive mechanism includes a counter weight20, pairs of left and right winding transmission tools21aand21b,22aand22b, and23aand23b, and an elevating drive means24. The counter weight20is installed movably vertically inside the fixed column portion3in a rectangular column shape, and an elevating guide rail25can also be used if necessary. One ends of the first wounding transmission tools21aand21bare latched on upper portions of both left and right ends of the counter weight20, the other ends are latched on latching tools26aand26bfixed onto positions close to lower ends of the pair of left and right first mid-stage elevating column portions4aand4b, and intermediate portions are wound around pairs of left and right turning guide wheels27aand28aand27band28b, respectively, axially supported onto positions close to the upper end inside the fixed column portion3, and when the first mid-stage elevating column portions4aand4bare at the lower limit positions, the counter weight20is at its upper limit position.

One ends of the second winding transmission tools22aand22bare latched on latching tools29aand29bfixed to positions close to upper ends of both left and right sides of the fixed column portion3, the other ends are latched on latching tools30aand30bfixed to positions close to lower ends of the pair of left and right second mid-stage elevating column portions5aand5b, and intermediate portions are wound around turning guide wheels31aand31baxially supported on positions close to upper ends of the first mid-stage elevating column portions4aand4b. One ends of the third winding transmission tools23aand23bare latched on latching tools32aand32bfixed onto positions close to the upper ends of the second mid-stage elevating column portions5aand5b, the other ends are latched on latching tools33aand33bfixed onto positions at intermediate heights of the pair of left and right final-stage elevating portions6aand6b, and the intermediate portions are wound around turning guide wheels34aand34baxially supported on positions near upper ends of the second mid-stage elevating column portions5aand5b. As the winding transmission tools21aand21bthrough23aand23b, chains or wire ropes may be used, and as the turning guide wheels27athrough28b,31aand31b, and34aand34b, sprockets, wheels, or pulleys can be used.

The elevating drive means24includes a motor37for driving and interlocks the turning guide wheels27aand27bon the counter weight20side around which the pair of left and right first winding transmission tools21aand21bare wound with each other via chains35aand35band gear trains36aand36b, and elevates the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3by rotating forward or reverse the first winding transmission tools21aand21b. The weight of the counter weight20can be set to be substantially equal to or slightly lighter than the total weight of all elevating members that elevate with respect to the fixed column portion3, that is, the mid-stage elevating column portions4athrough5b, the final-stage elevating portions6aand6b, the horizontal joint member13, and the transfer means14.

With the constitution described above, as shown inFIG. 1andFIG. 3, when the multistage extensible column1is in a contracted state and the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bare at the lower limit positions, the transfer means14is at its lower limit position closest to the floor surface, and the counter weight20is at its upper limit position inside the fixed column portion3. The height of the entire transfer device in this state is equal to the height of the upper ends of the fixed column portion3and the mid-stage elevating column portions4athrough5barranged parallel at substantially the same level. From this state, when the motor37of the elevating drive means24is actuated to drive and rotate the turning guide wheels27aand27baround which the first winding transmission tools21aand21bare wound via gear trains36aand36band chains35aand35bin a direction in which the first winding transmission tools21aand21blift the first mid-stage elevating column portions4aand4b, according to upward movements of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, the second winding transmission tools22aand22bof the first mid-stage elevating column portions4aand4bare relatively pulled downward by the latching tools29aand29bon the fixed column portion3side, whereby the second mid-stage elevating column portions5aand5bare lifted via the latching tools30aand30bwith respect to the first mid-stage elevating column portions4aand4bbeing raised. Further, according to the upward movements of the second mid-stage elevating column portions5aand5bwith respect to the first mid-stage elevating column portions4aand4b, the third winding transmission tools23aand23bof the second mid-stage elevating column portions5aand5bare relatively pulled downward by the latching tools32aand32bon the first mid-stage elevating column portion4aand4bsides, and the final-stage elevating portions6aand6bare lifted via the latching tools33aand33bwith respect to the first mid-stage elevating column portions4aand4bbeing raised.

According to the above-described action, as shown inFIG. 2andFIG. 4, when the first mid-stage elevating column portions4aand4brise to their upper limit positions with respect to the fixed column portion3, that is, to the upper limit positions at which about halves of the whole heights of the first mid-stage elevating column portions4aand4bproject upward from the fixed column portion3, the second mid-stage elevating column portions5aand5brise with respect to the first mid-stage elevating column portions4aand4bby the same distance as the rising distance of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, and further, the final-stage elevating portions6aand6brise with respect to the second mid-stage elevating column portions5aand5bby the same rising distance as that of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, and finally, the transfer means14positioned at the lower ends of the final-stage elevating portions6aand6brise to the upper limit positions near the upper ends of the first mid-stage elevating column portions4aand4bmoved up with respect to the fixed column portion3. When this multistage extensible column1is extended from a fully contracted state to a fully extended state, the weight of the counter weight20is applied upward to the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bvia the winding transmission tools21aand21bthrough23aand23b, so that the load on the motor37of the elevating drive means24is sufficiently reduced.

When the transfer means14at the upper limit position shown inFIG. 2andFIG. 4is lowered and returned to the original lower limit position shown inFIG. 1andFIG. 3, the motor37of the elevating drive means24is actuated to rotate in reverse the turning guide wheels27aand27baround which the first winding transmission tools21aand21bare wound in a direction in which the first winding transmission tools21aand21blift the counter weight20, whereby due to gravity, the final-stage elevating portions6aand6blower to the lower limit positions with respect to the second mid-stage elevating column portions5aand5b, the second mid-stage elevating column portions5aand5blower to the lower limit positions with respect to the first mid-stage elevating column portions4aand4b, and further, the first mid-stage elevating column portions4aand4blower to the lower limit positions with respect to the fixed column portion3, and finally, the transfer means14at the upper limit position shown inFIG. 2andFIG. 4lowers and returns to the original lower limit position shown inFIG. 1andFIG. 3.

The transfer means14which can thus be moved vertically between the lower limit position and the upper limit position by extending and contracting the multistage extensible column1between the fully contracted state and the fully extended state can be advanced and withdrawn horizontally between the withdrawing limit position shown inFIG. 1Aand the advancing limit position shown inFIG. 2A, so that for example, as shown inFIG. 1AandFIG. 2A, the transfer device constituted as described above can be used as a means for transferring an object W between the floor surface conveyance line39using the conveyance carriage38that travels on a fixed traveling path on the floor surface and a load cradle41set on an upstairs slab40positioned just above the floor surface conveyance line39.

Operations for scooping up and down the object W by forking operations performed by the combination of elevating movements of the transfer means14according to the extending and contracting movements of the multistage extensible column1and horizontal advancing and withdrawing movements between the withdrawing limit position and the advancing limit position of the running forks15aand15bof the transfer means14are conventionally known, so that description thereof will be omitted. In the example shown inFIG. 1AandFIG. 2A, an object W loaded on the conveyance carriage38stopped at a predetermined position of the floor surface conveyance line39is scooped sideward from the conveyance carriage38by an object scooping operation performed by combining the advancing movements of the running forks15aand15bof the transfer means14at the lower limit position to the advancing limit positions, the upward movement by a unit distance of the transfer means14from the lower limit position, the withdrawing movements of the running forks15aand15bto the withdrawing limit positions from the advancing limit positions, and thereafter, the transfer means14on which the object W is loaded is moved up to the upper limit position. Contrary to the object scooping operation, by an object unloading operation performed by combining the advancing and withdrawing movements of the running forks15aand15band the elevating movement of the transfer means14, the object W on the transfer means14can be unloaded onto the load cradle41of the upstairs slab40. As a matter of course, on the contrary, it is also possible that the object W is transferred onto the conveyance carriage38stopped at a predetermined position of the floor surface conveyance line39from the load cradle41of the upstairs slab40.

In the first embodiment described above, the withdrawing limit positions of the running forks15aand15bof the transfer means14are positions projecting sideward of the multistage extensible column1, so that the transfer means14elevates while cantilevered on the final-stage elevating portions6aand6beven when the running forks15aand15bare at the withdrawing limit positions. Therefore, the object W which is conveyed vertically while supported on the transfer means14applies a great rotating (falling) moment to the horizontal joint member13supporting the transfer means14, and eventually, to the multistage extensible column1. The floor surface area occupied by the transfer device also increases.

Next, a second embodiment for solving this problem will be described with reference toFIG. 5throughFIG. 8. In this embodiment, two multistage extensible columns51A and51B are arranged parallel. In the multistage extensible columns51A and51B, on the sides facing each other of fixed column portions3aand3bstood on a common base52, first mid-stage elevating column portions4aand4b, second mid-stage elevating column portions5aand5b, and final-stage elevating portions6aand6bare arranged in the same manner as in the aforementioned embodiment, and a horizontal joint member13is laid between lower ends of the pair of left and right final-stage elevating portions6aand6bpositioned on the sides facing each other of the multistage extensible columns51A and51B, and on this horizontal joint member13, a transfer means14is mounted.

In this embodiment, the running forks15aand15bat the withdrawing limit positions of the transfer means14can be positioned between the pair of left and right multistage extensible columns51A and51B (between the pair of left and right final-stage elevating portions6aand6b), so that the distance between the pair of left and right multistage extensible columns51A and51B (between the pair of final-stage elevating portions6aand6b) is set so that the object W supported by the running forks15aand15bcan be drawn into the position between the pair of left and right multistage extensible columns51A and51B (between the pair of left and right final-stage elevating portions6aand6b). The constitutions of the elevating guide means of the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bare basically the same as in the aforementioned first embodiment, so that the same reference numerals are added in the drawing and description thereof will be omitted, however, the extending and contracting drive mechanism of the multistage extensible columns51A and51B is slightly different from that of the aforementioned first embodiment.

That is, in this second embodiment, for each of the multistage extensible columns51A and51B, the counter weight20aor20band the elevating drive means24aor24bare provided. The counter weights20aand20bare installed in the fixed column portions3aand3bof the respective multistage extensible columns51A and51B and suspended by the first winding transmission tools21aand21bof the multistage extensible columns51A and51B, respectively. In the respective elevating drive means24aand24b, motors37aand37binterlocked with and joined to the turning guide wheels27aand27baround which the first winding transmission tools21aand21bin the respective multistage extensible columns51A and51B are wound are provided, respectively, and by these motors37aand37b, the turning guide wheels27aand27bare driven to rotate, respectively, and the motors37aand37bare actuated electrically in synchronization with each other so that the first mid-stage elevating column portions4aand4bof the multistage extensible columns51A and51B can be driven and elevated in synchronization with each other. As a matter of course, it is also allowed that the turning guide wheels27aand27bof the multistage extensible columns51A and51B are mechanically interlocked with and joined to each other by using an interlocking shaft supported horizontally along the common base52and by using this interlocking means, the turning guide wheels27aand27bare driven to rotate by one motor.

Further, as a transfer means, a type which can advance the running forks15aand15bforward and rearward by setting its withdrawing limit position as a home position is known, and as in the case of the third embodiment shown inFIG. 9, when the second embodiment is constituted by using this type of transfer means42, the object W can be transferred to both front and rear sides with respect to the elevating conveyance position between the multistage extensible columns51A and51B, so that for example, as in the case of the third embodiment shown inFIG. 9, when the floor surface conveyance line39and the overhead conveyor line43are separated horizontally in a plan view, it is possible that the transfer device is installed at an intermediate position between the floor surface conveyance line39and the overhead conveyor line43in the plan view so that the object W can be transferred between the conveyance carriage38stopped at a predetermined position on the floor surface conveyance line39and an object suspending conveyance hanger44stopped at a predetermined position on the overhead conveyor line43.

Next, a fourth embodiment of the second aspect of the invention carried out as a transfer device will be described with reference to the accompanyingFIG. 10throughFIG. 12. The transfer device of this fourth embodiment has the same constitution except for the extending and contracting drive mechanism of the multistage extensible column1as that of the transfer device of the above-described first embodiment, so that the same reference numerals are attached and description thereof will be omitted.

The extending and contracting drive mechanism of the multistage extensible column1will be described. As shown inFIG. 12, elevating drive means120which drive and elevate the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3are provided, and the first mid-stage elevating column portions4aand4band the second mid-stage elevating column portions5aand5bare provided with pulley-wound suspending chains121a,121b,122a, and122b. The elevating drive means120include endless winding suspending chains125aand125bwhich are hung vertically by a pair of upper and lower guide wheels123aor123band124aor124band latched at one point on the first mid-stage elevating column portions4aand4bvia latching tools126aand126b, and a driving device127which drives to rotate in an interlocking manner these endless winding suspending chains125aand125b. The driving device127includes a motor128and gear trains129aand129band winding transmission tools130aand130bfor transmitting the rotation of the output shaft of the motor128to the upper guide wheels23aand24aof the endless winding suspending chains25aand25b. As the endless winding suspending chains125aand125b, chains or wire ropes are used, and as the winding transmission tools130aand130b, chains or timing belts are used.

As the elevating drive means120, instead of the endless winding suspending chains125aand125b, other various methods using rack pinion gears or electric screw shafts can be used as long as they can drive and elevate the pair of left and right first mid-stage elevating column portions4aand4bin synchronization with each other.

The pulley-wound suspending chains121aand121bprovided in the first mid-stage elevating columns4aand4bare laid in a pulley-wound manner around the guide wheels131aand131baxially supported on the upper ends of the first mid-stage elevating column portions4aand4b, and one ends thereof are latched on positions near the upper end of the fixed column portion3via latching tools132aand132b, and the other ends are latched on positions near the lower ends of the second mid-stage elevating column portions5aand5bvia latching tools133aand133b. The pulley-wound suspending chains122aand122bprovided in the second mid-stage elevating column portions5aand5bare laid in a pulley-wound manner around the guide wheels134aand134baxially supported on the upper ends of the second mid-stage elevating column portions5aand5b, one ends thereof are latched on the positions near the upper ends of the first mid-stage elevating column portions4aand4bvia latching tools135aand135b, and the other ends thereof are latched on the final-stage elevating portions5aand5bvia latching tools136aand136b. As these pulley-wound suspending chains121a,121b,122a, and122b, chains or wire ropes are used.

On both left and right sides of the fixed column portion3, fluid pressure cylinders137A and137B which urge the first mid-stage elevating column portions4aand4bupward are disposed, and in the first mid-stage elevating column portions4aand4b, fluid pressure cylinders138A and138B which urge the second mid-stage elevating column portions5aand5bupward are disposed, and in the second mid-stage elevating column portions5aand5b, fluid pressure cylinders139A and139B which urge the final-stage elevating portions6aand6bupward are disposed.

The upper ends of the cylinder main bodies137aof the fluid pressure cylinder137A and137B are joined to brackets140aand140bprojecting from positions near the upper ends of both left and right sides of the fixed column portion3via support shafts141aand141b, and free ends of piston rods137bprojecting from the lower ends of the cylinder main bodies137aare connected to positions near the lower ends of the first mid-stage elevating column portions4aand4bvia the support shafts142aand142b. The upper ends of cylinder main bodies138aof the fluid pressure cylinders138A and138B are joined to brackets143aand143bprojecting from positions near the upper ends of the first mid-stage elevating column portions4aand4bvia support shafts144aand144b, and free ends of piston rods138bprojecting from lower ends of the cylinder main bodies138aare connected to positions near the lower ends of the second mid-stage elevating column portions5aand5bvia support shafts145aand145b. Then, upper ends of cylinder main bodies139aof the fluid pressure cylinders139A and139B are joined to brackets146aand146bprojecting from positions near the upper ends of the second mid-stage elevating column portions5aand5bvia support shafts147aand147b, and free ends of piston rods139bprojecting from the lower ends of the cylinder main bodies139aare connected to positions near the lower ends of the final-stage elevating portions6aand6b.

As shown inFIG. 14, to the advancing sides of the piston rods137aof the cylinder main bodies137aof the fluid pressure cylinders137A and137B which urge the first mid-stage elevating column portions4aand4bupward, fluid pressure supply pipes150aand150bfrom a pressure adjuster149are connected via pressure supply/open switching valves151aand151b, and to the advancing sides of the piston rods138bof the cylinder main bodies138aof the fluid pressure cylinders138A and138B which urge the second mid-stage elevating column portions5aand5bupward, fluid pressure supply pipes153aand153bfrom a pressure adjuster152are connected via pressure supply/open switching valves154aand154b. For fluid pressure cylinders139A and139B which urge the final-stage elevating portions6aand6bupward, two pressure adjusters155and156are provided in parallel, and fluid pressure supply pipes157aand157band158aand158bfrom the pressure adjusters155and156are connected to the fluid pressure supply pipes160aand160b, respectively, via switching valves159aand159b, and these fluid pressure supply pipes160aand160bare connected to the advancing sides of the piston rods139bof the cylinder main bodies139avia pressure supply/open switching valves161aand161b.

The pressure adjusters149,152,155, and156are connected to a pressure fluid (for example, compressed air) supply source162, and the fluid pressure (for example, air pressure, the same applies to the following description) F4to be supplied to the fluid pressure cylinders137A and137B from the pressure adjuster149is set to be substantially balanced with the total weight W3of the first mid-stage elevating column portions4aand4b, the fluid pressure F3to be supplied to the fluid pressure cylinders138A and138B from the pressure adjuster152is set to be substantially balanced with the total weight W2of the second mid-stage elevating column portions5aand5b, the fluid pressure F2to be supplied to the fluid pressure cylinders139A and139B from the pressure adjuster155is set to be substantially balanced with the total weight W1of the final-stage elevating portions6aand6b, and the fluid pressure F1to be supplied to the fluid pressure cylinders139A and139B from the pressure adjuster156is set to be substantially balanced with the sum (W0+W1) of the total weight W1of the final-stage elevating portions6aand6band the weight W0of the object W with the fixed weight to be loaded on the transfer means14(object support). In this embodiment, the fluid pressure cylinders137A through139B are arranged in pairs of left and right with respect to one elevating member, so that in actuality, the fluid pressures to be supplied to the respective fluid pressure cylinders137A through139B are halves of F1through F4as shown inFIG. 14.

In the above-described constitution, as shown inFIG. 10andFIG. 12, when the multistage extensible column1is in a contracted state and the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bare at their lower limit positions, the transfer means14is at the lower limit position closest to the floor surface, and piston rods137bthrough139bof the fluid pressure cylinders137A through139B are in a fully extended state. In this state, it is preferable that the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bare supported by receiving tools provided on the base2side or on the mid-stage elevating column portions4athrough5band the fixed column portion3just below the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bso that no load is applied to the endless winding suspending chains125aand125band the pulley-wound suspending chains121athrough122bof the elevating drive means120. With this constitution, when the multistage extensible column1is in a contracted state, the pressure supply/open switching valves151aand151b,154aand154b, and161aand161bshown inFIG. 14are switched to the open side to cut-off the pressure fluid supply to the fluid pressure cylinders137A through139B.

Then, when the motor128of the driving device127of the elevating drive means120is actuated from the contracted state of the multistage extensible column1to drive and rotate the endless winding suspending chains125aand125bin a direction of lifting the first mid-stage elevating column portions4aand4b, according to upward movements of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, the pulley-wound suspending chains121aand121bof the first mid-stage elevating column portions4aand4bare pulled relatively downward by the latching tools132aand132bon the fixed column portion3side to lift the second mid-stage elevating column portions5aand5bwith respect to the lifted first mid-stage elevating column portions4aand4bvia the latching tools133aand133b. Further, according to the upward movements of the second mid-stage elevating column portions5aand5bwith respect to the first mid-stage elevating column portions4aand4b, the pulley-wound suspending chains122aand122bof the second mid-stage elevating column portions5aand5bare pulled relatively downward by the latching tools135aand135bon the sides of the first mid-stage elevating column portions4aand4bsides to lift the final-stage elevating portions6aand6bwith respect to the lifted first mid-stage elevating column portions4aand4bvia the latching tools136aand136b.

According to the above-described working, as shown inFIG. 11andFIG. 13, when the first mid-stage elevating column portions4aand4brise to the upper limit positions with respect to the fixed column portion3, the second mid-stage elevating column portions5aand5brise by the same distance as the rising distance of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, and further, the final-stage elevating portions6aand6brise with respect to the second mid-stage elevating column portions5aand5bby the same distance as the rising distance of the first mid-stage elevating column portions4aand4bwith respect to the fixed column portion3, and finally, the final-stage elevating portions6aand6brise to the upper limit positions.

When the multistage extensible column1is thus extended from the fully contracted state into the fully extended state, if the fluid pressure cylinders137A through139B which urge the mid-stage elevating column portions4athrough5band the final-stage elevating portions6aand6bupward are absent, to the first mid-stage elevating column portions4aand4b, the following gravity:
f1=3W1+2W2+W3
is applied when the object W is not loaded on the transfer means14, and
the following gravity:
f2=3W0+3W1+2W2+W3
is applied when the object W is loaded on the transfer means14,
provided that:

W0=weight of object W

W2=total weight of second mid-stage elevating column portions5aand5b

W3=total weight of first mid-stage elevating column portions4aand4b.

Therefore, generally, the first mid-stage elevating column portions4aand4bare urged upward with respect to the fixed column portion3by a balance weight with the weight f1or f2, however, with the above-described constitution of the present invention, when the multistage extensible column1is extended, the pressure supply/open switching valves151aand151b,154aand154b, and161aand161bare switched to the pressure supply side, and further, when the transfer means14is empty, the switching valves159aand159bare switched to the pressure adjuster155side to supply the fluid pressure F2to the fluid pressure cylinders139A and139B, and when the object W is loaded on the transfer means14, the switching valves159aand159bare switched to the pressure adjuster156side to supply the fluid pressure F1to the fluid pressure cylinders139A and139B, whereby the following relationships:
F1=W0+W1
F2=W1
F3=W2
F4=W3
are satisfied as described above, and therefore, in both of the cases where the object W is loaded on and not loaded on the transfer means14, the whole elevating section including the object W is made weightless theoretically, so that the endless winding suspending chains125aand125bof the elevating drive means150are driven to rotate by a small driving force just enough to overcome the friction resistance of the relative elevating portions and can extend the multistage extensible column1from the fully contracted state into the fully extended state.

When a plurality of types of objects W with varied weights W0are handled, a plurality of pressure adjusters156which can supply fluid pressures F1=W0+W1corresponding to the weights W0of the object types and switching valves for selectively using the pressure adjusters156may be used together. In the above-described constitution, the pressure adjuster155to be used when the transfer means14is empty and the pressure adjuster156to be used when the object W is loaded on the transfer means14are selectively used, however, it is also allowed that one variable pressure adjuster which can adjust the fluid pressure to be outputted according to the loading weight is used.

To lower and return the transfer means14at the upper limit position shown inFIG. 11andFIG. 13to the original lower limit position shown inFIG. 10andFIG. 12, the motor128of the driving device127of the elevating drive means120is actuated in reverse to rotate the endless winding suspending chains125aand125bin a reverse direction of pulling-down the first mid-stage elevating column portions4aand4b, whereby the final-stage elevating portions6aand6blower to the lower limit positions with respect to the second mid-stage elevating column portions5aand5b, the second mid-stage elevating column portions5aand5blower to the lower limit positions with respect to the first mid-stage elevating column portions4aand4b, and further, the first mid-stage elevating column portions4aand4blower to the lower limit positions with respect to the fixed column portion3, and finally, the transfer means14at the upper limit position shown inFIG. 11andFIG. 13lowers and returns to the original lower limit position shown inFIG. 10andFIG. 12.

By thus extending and contracting the multistage extensible column1between the fully contracted state and the fully extended state, similar to the transfer means14of the first embodiment described above, for example, as shown inFIG. 10AandFIG. 11A, the transfer means14capable of being moved vertically between the lower limit position and the upper limit position can be used as a means for transferring an object W between the floor surface conveyance line39using the conveyance carriage38that travels on a fixed traveling path on the floor surface and a load cradle41set on the upstairs slab40positioned just above the floor surface conveyance line39. The operations for scooping up and down the object W between the conveyance carriage38and the transfer means14and the operations for scooping up and down the object W between the transfer means14and the load cradle41are performed in the same manner as those of the transfer device of the first embodiment described above.

The elevating conveyance device (transfer device) based on the second aspect of the invention can also be carried out according to the same embodiment as the aforementioned second embodiment shown inFIG. 5throughFIG. 8. That is, the transfer device of the fifth embodiment shown inFIG. 15throughFIG. 18is the same in constitution as the transfer device of the aforementioned second embodiment except for the extending and contracting drive mechanism of the multistage extensible column1, so that the same reference numerals are attached to the same components and description thereof is omitted.

In particular, in this fifth embodiment, the elevating drive means120A and120B are provided for the multistage extensible columns51A and51B, respectively. These elevating drive means120A and120B include endless winding suspending chains125aand125bwhich drive and elevate the first mid-stage elevating column portions4aand4bof the respective multistage extensible columns51A and51B, and driving devices127aand127bwhich drive these endless winding suspending chains125aand125b, respectively, and as the driving devices127aand127b, two motors128aand128bwhich are interlocked with and joined to the respective upper guide wheels123aand123bof the endless winding suspending chains125aand125bvia the winding transmission tools130aand130bare provided, and both motors128aand128bare electrically actuated in synchronization with each other so as to drive and elevate the first mid-stage elevating column portions4aand4bof the multistage extensible columns51A and51B in synchronization with each other. As a matter of course, it is also allowed that the upper guide wheels123aand123bof the endless winding suspending chains125aand125bin both multistage extensible columns51A and51B are mechanically interlocked with and joined to each other by using an interlocking shaft supported horizontally along the common base52, and by using this interlocking means, the endless winding suspending chains125aand125bare driven to rotate by one motor.

FIG. 19shows a sixth embodiment using, as a transfer means of the fifth embodiment, a transfer means42including running forks15aand15bthat can be advanced forward and rearward from a fully withdrawn position as a home position. In this sixth embodiment, the object W can be transferred to both the front and rear sides of an elevating conveyance position between the multistage extensible columns51A and51B, so that as described in the aforementioned third embodiment, when the floor surface conveyance line39and the overhead conveyor line43are separated laterally in a plan view, by setting the above-described transfer device at an intermediate position between the floor surface conveyance line39and the overhead conveyor line43in the plan view, the object W can be transferred between the conveyance carriage38stopping at a fixed position on the floor surface conveyance line39and a object suspending conveyance hanger44stopping at a fixed position on the overhead conveyor line43.

In the above-described embodiment, the mid-stage elevating column portions and the final-stage elevating portions are provided in pairs of left and right in parallel, and these pairs of left and right mid-stage elevating column portions and left and right final-stage elevating portions move vertically in synchronization with each other or integrally, however, when the object W is a small-sized light-weight object, as in the case of the seventh embodiment shown inFIG. 20, the present invention can also be carried out as an elevating conveyance device using a multistage extensible column172including a fixed column portion3, one first mid-stage elevating column portion4, one second mid-stage elevating column portion5, and one final-stage elevating portion6. The reference numeral173denotes an object support base provided in a projecting manner so as to be cantilevered from the final-stage elevating portion6. In the figure the reference numerals121and122denote pulley-wound suspending chains,131and134denote guide wheels,132,133,135, and136denote end portion latching tools of the pulley-wound suspending chains121and122,137through139denote fluid pressure cylinders, and description of these is omitted since these correspond to the pulley-wound suspending chains121athrough122b, guide wheels131a,131b,134a, and134b, latching tools132athrough133band135athrough136b, and fluid pressure cylinders137A through139B of the fourth embodiment, respectively.

As in the seventh embodiment shown inFIG. 20, as the elevating drive means120which drives and elevates the first mid-stage elevating column portion4with respect to the fixed column portion3, a fluid pressure cylinder174can be used. In the fluid pressure cylinder174shown in the figure, a cylinder main body175ais joined to the fixed column portion3side by a support shaft176, and the tip end of the piston rod175bprojecting upward is joined to the first mid-stage elevating column portion4side by a support shaft177, however, it is also allowed that, similar to the fluid pressure cylinders137through139and137A through139B, the cylinder main body175ais joined to the first mid-stage elevating column portion4side and the tip end of a piston rod175bprojecting downward is joined to the fixed column portion3side. As a matter of course, it is allowed that the fluid pressure cylinders137through139and137A through139B are set upside down and cylinder main bodies are joined to the fixed column portion or the previous elevating column portion similar to the fluid pressure cylinder174, and tip ends of the piston rods projecting upward are joined to the next elevating column portion or final-stage elevating column portion. As shown inFIG. 20, when the fluid pressure cylinder174is used as the elevating drive means120, it is possible that the fluid pressure cylinder137which urges the first mid-stage elevating column portion4upward with respect to the fixed column portion3is omitted and the fluid pressure cylinder174as the elevating drive means120is commonly used as the fluid pressure cylinder137as a balance weight which urges the first mid-stage elevating column portion4upward. In other words, the fluid pressure cylinder as a balance weight which urges the first mid-stage elevating column portion4upward can be commonly used as the elevating drive means120.

In the seventh embodiment ofFIG. 20, only one mid-stage elevating column portion4is driven and elevated by the elevating drive means120, and synchronous elevating of the pair of left and right first mid-stage elevating column portions4aand4bis not necessary, so that the elevating drive means120can be easily constituted by the fluid pressure cylinder174, however, even in the case of the elevating conveyance device using the pair of left and right first mid-stage elevating column portions4aand4b, by using an interlocking mechanism which synchronizes the vertical movements of the pair of left and right first mid-stage elevating column portions4aand4b, the fluid pressure cylinder can be used as the elevating drive means120even in the above-described embodiment using the pair of left and right mid-stage elevating column portions4aand4b.

In the above-described embodiment, as the mid-stage elevating column portions, the first mid-stage elevating column portions4aand4band the second mid-stage elevating column portions5aand5bare provided, however, if the lifting distance necessary for the transfer means14and42is shorter, the second mid-stage elevating column portions5aand5bcan be omitted, and on the contrary, if the lifting distance necessary for the transfer means14and42is longer, three or more mid-stage elevating column portions can be provided. It is a matter of course that examples of use of the transfer device are not limited to the illustrated examples.

Further, in the elevating conveyance device of the present invention, the transfer means14and42as an object support thereof that moves vertically, more specifically, the transfer means14and42including a load cradle that can advance and withdraw horizontally and consists of running forks15aand15bare provided, and even if the transfer means14and42which transfer an object horizontally are installed on an object support that moves vertically as in the embodiments described above, without limiting to the running fork type, various conventionally known conveyor type or drawing and pushing pusher type transfer means can also be used. As a matter of course, it is possible that only carriage guide rails are laid on the object support that moves vertically so that a conveyance carriage is transferred onto guide rails laid on a target floor surface, and according to the circumstances, it is also allowed that only an object support surface is provided as the object support that moves vertically and a cart or the like is transferred onto and from a target floor surface.

It should be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.