Patent ID: 12221332

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS.1to4, an embodiment of the apparatus for operating the fork holder supports is illustrated, according to the present invention, which is indicated overall with1.

The apparatus1carries two forks2, each provided with a respective upper portion3(or backrest) which serves as a rear abutment for the load; the upper portion3can be substituted in case of damage.

The apparatus1comprises a first frame4.

The first frame4comprises two shoulders5which are inserted and can slide, according to known modes, by means of the wheels6, or other similar means, in a vertical upright (not illustrated) of a forklift, manually or automatically driven.

The first frame4comprises fastening to which the lifting member is applied (not visible in the figures) of the apparatus1; also such member is not illustrated in detail, since it is not part of the present invention.

The shoulders5of the first frame4are connected to each other by a plate, omitted in the figures for the sake of clarity; the aforesaid plate has a first fastening7for first electric actuator means8.

The aforesaid first electric actuator means8comprise a linear electric actuator.

The first frame4also comprises connection means15for a second frame11.

The connection means15connect the second frame11to the first frame4so as to allow a rotation between the two frames4and11.

Generally, between the first frame4and the second frame11, a certain rotation is necessary, with respect to an intermediate position at 0°, so as to obtain a corresponding tilt of the forks2.

In some cases, for example for counter-balanced forklifts which work outside, such rotation is +7°/−4° with respect to the intermediate position; in other cases, for example internal warehouses, the rotation is usually +4°/−3° with respect to the intermediate position.

In the embodiment ofFIGS.1-4, the connection means15comprise upper guiding means9and lower guiding means10, arranged on the first frame4.

The connection means15also comprise upper sliding means12, slidable according to the direction F (FIG.2), and lower sliding means13, slidable according to the direction H (FIG.2).

In particular, the upper sliding means12and the lower sliding means13are arranged on the second frame11.

The upper guiding means9are arranged in the upper part of the shoulders5of the frame4, and are tilted upward, in the direction of the front part where the forks2are found; the aforesaid upper guiding means9have a predetermined tilt angle A.

With respect to a horizontal plane, the angle A can be comprised between 20° and 60°. According to one version of the present invention, the angle A can be about 40°.

The tilt angle A can be varied as a function of the movement geometry, of the second frame11with respect to the first frame4, that one wishes to obtain.

The upper guiding means9can comprise two, or more, rectilinear upper rails9aor the like, fixed to the upper portions of the shoulders5of the first frame4, and provided with respective longitudinal ribs in relief.

The upper sliding means12can comprise, consequently, two or more upper wheels12a, provided with respective circumferential grooves in which the ribs of the upper rails9aare engaged.

More in detail, the upper wheels12aare rotatably supported in respective upper appendages12bof the second frame11.

The lower guiding means10are arranged in the lower part of the frame4, on the shoulders5, towards the front part where the forks2are situated.

The lower guiding means10are substantially vertical; for example, the lower guiding means10have a tilt comprised between +30° and −30° with respect to the vertical.

Also for the lower guiding means10, different angles can be provided, always close to the vertical, in relation to the movement that one wishes to obtain.

The lower guiding means10can comprise two or more rectilinear lower rails10a, or the like, fixed to the lower portions of the shoulders5of the first frame4, and provided with respective longitudinal ribs in relief.

The lower sliding means13can comprise, consequently, two or more lower wheels13a, provided with respective circumferential grooves in which the ribs of the lower rails10aare engaged.

More in detail, the lower wheels13aare rotatably supported in respective lower appendages13bof the second frame11.

As stated, the second frame11rests on the upper and lower guiding means9,10of the first frame4, by means of the corresponding upper sliding means12and lower sliding means13.

The geometric arrangement of the aforesaid guiding means9,10and sliding means12,13allows obtaining a certain rotation of the second frame11with respect to the first frame4(e.g. +7/−4°, or +4°/−3°, but other values are also possible, which depend on the specific application), considering the two end positions; consequently, one obtains a corresponding tilt of the plane of the forks2with respect to a horizontal plane.

The rotation of the second frame11, with respect to the first frame4, is due to the movement of the sliding means12and13on the guiding means9and10; due to the particular geometric arrangement of the aforesaid guiding means9,10and sliding means12,13described above, the rotation axis B of the second frame11, with respect to the first frame4, is virtual, and is found in a position (FIG.2), which is more advanced with respect to the known solutions, i.e. beyond the plane of the vertical part of the forks2, and hence substantially at the horizontal portion of the forks2.

The second frame11also comprises a second fastening14for the first linear electric actuator8.

The aforesaid first linear electric actuator8can be a linear electric actuator of commercial type.

For example, the first linear electric actuator8can be similar to that illustrated in the U.S. Pat. No. 6,101,889A; for size reasons, it develops a more limited force with respect to a corresponding oil-hydraulic actuator.

Alternatively, such actuator8can be of the type with trapezoidal screw, or it can be a screw actuator with recirculating ball nut.

As can be observed inFIGS.2and3, the first actuator8is installed in a nearly vertical position; its size in the apparatus1, especially in transverse sense, is consequently quite limited.

In practical operation, the first actuator8pushes or pulls the second fastening14, thus moving the upper part of the second frame11according to the arrow F (in the two senses,FIG.2), and the lower part according to the arrow H (in the two senses,FIG.2); in this manner, a rotation of the second frame11is determined with respect to the first frame4, around the rotation axis B.

The second frame11comprises a second guiding means16which support a third frame17, which can be horizontally translated with respect to the second frame11.

The second guiding means16comprise a first upper horizontal guide18, and a first lower horizontal guide19.

The second guiding means16also comprise first rollers20aand second rollers20b, which slidable support the third frame17, allowing the aforesaid frame17to be moved to the right and left with respect to the second frame11.

In one version of the present invention, the first upper18and lower19guides are of prismatic type, and have substantially C-shaped cross section; in use, the first upper18and lower19guides define the respective longitudinal grooves which are directed upward and downward.

The first rollers20aare rotatably supported by respective opposite first plates20cfixed to the first frame11, have the respective rotation axes parallel to each other and they are mounted in a mirrored manner.

The first rollers20aare slidable within the longitudinal grooves of the first upper guide18and of the first lower guide19.

The second rollers20bare rotatably supported by the first frame11in a manner such that the plane in which their rotation axes lie is perpendicular to the plane in which the rotation axes of the first rollers20alie.

The second rollers20bare engaged in rolling along the opposite flat internal faces of the first upper guide18and of the first lower guide19.

Due to the possibility to adjust the position of the first rollers20aand of the second rollers20b, it is possible to nearly completely cancel the clearances between rollers20a,20band guides18,19, and consequently also the third frame17can slide horizontally nearly without clearances with respect to the second frame11.

The second frame11comprises a second linear electric actuator21for the movement in horizontal sense of the third frame17, along the second guiding means16.

Also the second linear electric actuator21can be of commercial type, for example of the same type as the first actuator8.

It can be suitably selected from among the actuators available on the market, in relation to the force to be exerted and to the travel to be executed in order to obtain the translation of the third frame17with respect to the second frame11.

The second linear electric actuator21comprises one end articulated to a lateral side of the second frame11, and a second end articulated to an upper portion of the third frame17.

The third frame17comprises adjustment means22for adjusting the mutual distance between the forks2.

The adjustment means22comprise a second upper horizontal guide23a, and a second lower horizontal guide23b, fixed to the second frame17.

The second upper guide23aand the second lower guide23bare also of prismatic type, with substantially C-shaped cross section, and define respective mutually facing longitudinal grooves.

The adjustment means22also comprise a first support24and a second support25, to which the two forks2are respectively fixed.

The adjustment means22also comprise third rollers26aand fourth rollers26b, rotatably supported by the first support24and by the second support25.

The first support24and the second support25are shaped substantially as plates, and in use lie on a same plane.

The third rollers26aare rotatably supported, by the first support24and by the second support25, with the respective rotation axes orthogonal to the plane of the first support24and of the second support25.

The fourth rollers26bare rotatably supported by second plates26c, which are extended from the first support24and from the second support25, perpendicular to the planes of the latter.

The rotation axes of the fourth rollers26blie on a plane which is perpendicular to the planes in which the rotation axes of the third rollers26alie.

The third rollers26aare slidable within the longitudinal grooves of the second upper guide23aand of the second lower guide23b.

The fourth rollers26bare engaged in rolling along the flat external faces of the second upper guide23aand of the second lower guide23b.

Also in this case, due to the possibility to adjust the position of the rollers26a,26bwith respect to the guides23a.23b, the clearances between rollers and guides can be nearly completely canceled, and consequently also the two supports24,25can slide horizontally nearly without clearances with respect to the third frame17.

The first support24and the second support25are respectively actuated by a third actuator27and by a fourth actuator28, in a manner such to be able to vary the mutual distance between the forks2.

Also the third actuator27and the fourth actuator28are linear electric actuators of commercial type, for example of the same type as the first actuator8and as the second actuator21.

The third actuator27and the fourth actuator28are suitably selected from among those available on the market, in relation to the force to be exerted and to the travel to be executed, in order to obtain the desired movements.

The third actuator27has one end articulated to a first bracket29afixed to one of the sides of the third frame17, and the other end articulated to the first support24.

Likewise, the fourth actuator28has one end articulated to a second bracket29bfixed to the other of the sides of the third frame17, and the other end articulated to the second support25.

The third actuator27and the fourth actuator28can be installed in a manner so to have the respective actuation senses opposite, such that, for example, a command of extension of the actuators causes a mutual moving away of the forks2; in an opposite manner, the command of return of the actuators causes a mutual approaching of the forks2.

InFIGS.5,6, a second embodiment is illustrated of the apparatus for operating the fork holder supports, according to the present invention.

This version of the present invention differs from the preceding in that it comprises four fork holder supports for four forks2a,2b,2c,2din a manner such to be able to treat two pallets at the same time, and thus increasing the productivity.

In the description of this further embodiment, the parts that are equal or similar to the preceding embodiment maintain the same reference numbers.

The four forks2a,2b,2c,2dcan also be set close to each other two-by-two, for example for manipulating only one pallet.

In this version of the invention, the second frame11comprises second guiding means16, which slidably support the first support24and the second support25.

The first support24and the second support25are respectively directly fixed to the central forks2a,2b.

The second frame11also comprises first telescopic supporting means30and second telescopic supporting means31, respectively, for the two lateral forks2c,2d.

In other words, the first telescopic supporting means30connect, in a slidably adjustable manner, the first central fork2ato the first lateral fork2c, while the second telescopic supporting means31connect, in a slidably adjustable manner, the second central fork2bto the second lateral fork2d.

The second guiding means16comprise a first upper horizontal guide18and a first lower horizontal guide19.

The second guiding means16also comprise first rollers20aand second rollers20b, which slidably support the first support24and the second support25, allowing the latter to be moved to the right and to the left with respect to the second frame11.

The first upper guide18and the first lower guide19are of prismatic type, and they have substantially C-shaped cross section; in use, the first upper18and lower19guides define respective mutually facing longitudinal grooves.

The first rollers20aare rotatably supported by first plates20cintegral, respectively, with the first support24and the second support25and have the respective rotation axes parallel to each other.

The first rollers20aare slidable within the longitudinal grooves of the first upper guide18and of the first lower guide19.

The second rollers20bare rotatably supported, respectively, by the first support24and by the second support25, in a manner such that the plane in which their rotation axes lie is perpendicular to the plane in which the rotation axes of the first rollers20alie.

The second rollers20bare engaged in rolling along an additional upper guide32and an additional lower guide33, associated respectively with the first upper guide18and with the first lower guide19.

The first support24is associated with first actuator means34, which allow the sliding thereof with respect to the second frame11in the desired sense.

Likewise, the second support25is associated with second actuator means35, which allow the sliding thereof with respect to the second frame11in the desired sense, i.e. in approaching or in moving away from the first support24.

The first actuator means34comprise, for example, a linear electric actuator having the fixed part connected to the second frame11, and the movable part connected to the first support24.

The second actuator means35can comprise, likewise, a linear electric actuator having the fixed part connected to the second frame11, and the movable part connected to the second support25.

The first actuator means34and the second actuator means35can be connected to the second frame11with opposite actuation senses, in a manner such that a command of extension of the movable part, imparted to both, determines the mutual moving away of the first support24and of the second support25, while a command of return of the movable part, imparted to both, determines a mutual approaching of the first support24and of the second support25.

The first telescopic supporting means30comprise a first external element36, having box-like conformation, fixed to the first support24, and a first internal element37, slidable within the first external element36: the lateral fork2cis connected to the first internal element37.

The first elements36,37are shaped so as to support the load due to the lateral fork2c, and to translate the lateral fork2cwith respect to the central fork2a.

Within the first external element36, slidable guiding means are provided for the first internal element37.

Such guiding means can comprise, for example, wheels, or the like, rotatably supported within the first external element36, which can roll on the external surface of the first internal element37.

The first telescopic supporting means30comprise a first actuator member38, installed within the first external element36, and connected to the first internal element37, for operating the translation in one sense or in the other of the latter.

Likewise, the second telescopic supporting means31comprise a second external element39, having box-like conformation, fixed to the second support25, and a second internal element40, slidable within the second external element39: the lateral fork2dis connected to the second internal element40.

The second elements39,40are shaped in a manner so as to support the load due to the lateral fork2d, and to translate the lateral fork2dwith respect to the central fork2b. Within the second external element39, slidable guiding means are provided for the second internal element40.

Such guiding means can comprise, for example, wheels, or the like, rotatably supported within the second external element39, which can roll on the external surface of the second internal element40.

The second telescopic supporting means31comprise a second actuator member41, installed within the second external element39, and connected to the second internal element40, for operating the translation in one sense or in the other of the latter.

The first actuator member38and/or the second actuator member41can be of commercial type, not very bulky, and which allows moving the first, second internal element37,40with respect to the first, second external element36,39.

The first actuator means34and the second actuator means35can perform both the function of means for adjusting the mutual distance between the two central forks2a,2b, and the function of means of lateral translation of the same central forks2a,2b; for the lateral translation of the central forks2a,2b, the respective first actuator means34and second actuator means35are both actuated towards the right or towards the left by means of an operative connection mode of master-slave type, while the lateral forks2c,2d, being mechanically connected to the central forks2a,2b, are moved therewith.

InFIG.7, the apparatus1, according to the embodiments of theFIGS.1-6, is illustrated with the forks2a,2b,2c,2din intermediate position, and with the values indicated of the movements of specific points taken as references.

InFIG.7, also the position of the center of gravity G of the load is shown: this is an estimated position, in consideration of the common dimensions of the load, and also in consideration of the fact that the load is normally uniform.

For example, with a load on a pallet, 1200 mm long and 1400 mm high, the position of the center of gravity G is found, in horizontal direction, at 600 mm from the upper abutment portion3, and in vertical direction, at 700 mm from the horizontal portions of the forks2a,2b,2c,2d.

As can be observed, supposing an angular travel of the forks2a,2b,2c,2dof 3° downward (FIG.8) and of 4° upward (FIG.9), the rotation axis B is found at a distance, from the upper abutment portion3, which varies from 376 mm of the upward-tilted position, to 397 mm of the downward-tilted position.

Consequently, the center of gravity G of the load undergoes an overall vertical movement of 26 mm, while the tips of the forks2a,2b,2c,2dundergo an overall vertical movement of 100 mm.

Supposing, therefore, the need to swing with load of 2000 kg, the work which the electric actuator means8must carry out is 520 J (20000 N×0.026 m).

In order to carry out a comparison, inFIG.10the same apparatus is shown in an operative configuration, corresponding to the prior art, in which the forks2a,2b,2c,2dare articulated to the first frame4at an upper pivot U (which, for improved comprehension, is represented coinciding with the rotation axes of the upper wheels12a).

As can be observed, the center of gravity G of the load, in this case, undergoes an overall vertical movement of 116 mm; in addition, the tips of the forks2a,2b,2c,2dundergo an overall vertical movement of 191 mm.

Supposing, therefore, the need once again to swing with load of 2000 kg, the work that the electric actuator means8must carry out is 2320 J (20000 N×0.116 mm).

Still in order to carry out a comparison, inFIG.11, the same apparatus is shown in an operative configuration, corresponding to the prior art, in which the forks2a,2b,2c,2dare articulated to the first frame4at a lower pivot L (which, for improved comprehension, is represented coinciding with the rotation axes of the lower wheels13a).

As is observed, the center of gravity G of the load, in this case, undergoes an overall vertical movement of 108 mm; in addition, the tips of the forks2a,2b,2c,2dundergo an overall vertical movement of 181 mm.

Supposing the need once again to swing with load of 2000 kg, the work that the electric actuator means8must carry out is 2160 J (20000 N×0.108 mm).

It is inferred that the energy required for carrying out the swing of the load with the solution according to the present invention is therefore considerably less than that required in the known solutions with upper or lower pivot (given the same angular travel in the swing), due to the fact that the rotation axis B of the forks2a,2b,2c,2dis found at a smaller distance from the center of gravity G of the load, with respect to the known solutions.

This allows using lower-power electric actuator means8, hence means also with more limited size.

Another important advantage consists of the fact that the vertical movement of the tips of the forks2a,2b,2c,2dis much more limited with respect to the solutions of known type. This is an advantage of operative type, since the steps of loading and unloading the pallet are facilitated, and in addition it is possible to better exploit the free space available above the pallet during storage.

It must also be added that a more limited movement of the tips of the forks2a,2b,2c,2dimproves the perception of the maneuvering space, and hence the confidence of the operator who commands the vehicle during the storage operations, which can therefore be quicker in executing of the operations: indeed, with the solutions of known type, the operator does not normally have a good view of the pallet when it is lifted, due to the high movement of the tips.

InFIG.12, a third embodiment of the invention is illustrated.

This embodiment differs from the preceding embodiments in that the upper guiding means9and/or the lower guiding means10are adjustable, in a manner to be able, consequently, to modify the position of the rotation axis B of the forks2a,2b,2c,2d.

In particular, the tilt of the upper rails9aand/or of the lower rails10acan be varied with respect to the fixed tilt provided in the preceding versions of the invention, such that also the position of the rotation axis B of the forks2a,2b,2c,2dcan be consequently varied. This modification can be useful for adapting the apparatus1to loads of different sizes and characteristics, always with the objective of obtaining a rotation axis B of the forks2a,2b,2c,2das close as possible to the center of gravity G of the load.

More in detail, in the version shown inFIG.12, for the sake of simplicity, only the tilt of the lower rails10ais adjustable.

Only by way of a non-limiting example, in the particular configuration ofFIG.12, the tilt of the lower rails10ais 13.5° with respect to the vertical position provided in the preceding embodiments.

As can be observed, in this configuration of the apparatus, the rotation axis B of the forks2a,2b,2c,2dis found, with reference to the horizontal direction, at a distance of about 600 mm from the upper abutment portion3, and hence is found substantially at the estimated position of the center of gravity G.

The overall vertical movement of the center of gravity G of the load, in this case, is only 3 mm.

It is therefore evident that this solution allows further reducing the energy required for the electric actuator means8in order to carry out the swing of the forks2a,2b,2c,2d. According to the invention, therefore, by modifying the tilt of the upper rails9aand/or of the lower rails10a, it is possible to modify the position of the rotation axis B of the forks2a,2b,2c,2das desired, with the variation of the characteristics of the load, and hence with the variation of the position of its center of gravity G (for example for very short or very long loads).

The tilt of the upper rails9aand/or of the lower rails10acan be varied in many different ways.

For example, such tilt can be varied manually.

Or, in one embodiment of the invention not represented in the figures, the tilt of the upper rails9aand/or of the lower rails10acan be varied by means of respective adjustment actuators, of any type suitable for this specific application.

InFIGS.13to19, a fourth embodiment is illustrated of the apparatus for operating the fork holder supports, according to the present invention.

Also this embodiment of the invention comprises four fork holder supports for four forks2a,2b,2c,2d, in a manner so as to be able to treat two pallets at the same time.

In the description of this further embodiment, the parts that are equal or similar to the preceding embodiment maintain the same reference numbers.

With regard to the characteristics of the four forks2a,2b,2c,2d, and of the possible movements of the latter, the considerations hold true that were set forth in the embodiment of theFIGS.5,6.

As shown inFIGS.9,10, the four forks2a,2b,2c,2dcan be set close to each other two-by-two, for example for manipulating only one pallet.

The apparatus1is fixed, by means of connection means15, to a first frame (not illustrated), vertically slidable in an upright of a manually or automatically driven forklift.

In this embodiment, the connection means15comprise an upper fastening42and a lower fastening43.

In the upper fastening42, a cam element44is hinged.

The cam element44comprises one or two profiles45.

The lower fastening43are instead fixed to the second frame11, which supports the forks2a,2b,2c,2din the manner described with regard to the preceding embodiment of theFIGS.5,6.

More in detail, the profile45is constituted by, or comprises, a circular sector, which has a geometric center “C” in a different position with respect to the upper fastening42, in which the cam element44is instead hinged.

In other words, the geometric center “C” is in an eccentric position with respect to the rotation center of the cam element44, rotation center which is at the upper fastening42. As shown inFIG.14, the apparatus1comprises first actuator means8comprising, in turn, a linear electric actuator.

The linear electric actuator of the first actuator means8is arranged, in use, in a nearly vertical position, between lower connection means46, provided in the second frame11, and upper connection means47, which are situated in the cam element44.

The second frame11also rotatably supports a roller48(or multiple rollers48), which rolls (or roll) on the profile45(or on the profiles45) of the cam element44.

Two first linear electric actuators8, of commercial type and not very bulky, can also be provided.

As shown in the schemes of theFIGS.17-19, the first linear electric actuator8, by moving the cam element44, rotating around the upper fastening42, indirectly determines a rotation of the second frame11around the lower fastening43, and hence a variation of tilt of the forks2a,2b,2c,2d.

The rotation of the cam element44, due to the actuation of the first linear electric actuator8, determines a horizontal movement of the roller48, so that the profile45approaches or moves away from the roller48itself at the upper fastening42, which is the rotation center of the circular sector that exemplifies the profile45; the circular sector, which as stated has center in “C”, is eccentric with respect to the upper fastening42, and determines the approaching or moving away of the roller48with respect to the aforesaid upper fastening42.

In other words, the rotation of the second frame11is, therefore, due to the movement, substantially horizontal, of the roller48(or of the rollers48) which is fixed to the second frame11, and rolls (or in any case is moved) along the profile45of the cam element44. In the configuration ofFIG.17, the cam element44is found in an intermediate position corresponding to the horizontal position of the horizontal part of the forks2a,2b,2c,2d, and also the first linear electric actuator8is found in an intermediate position.

In the configuration ofFIG.18, the cam element44is found in an upper end position, actuated by the first linear electric actuator8: such position of the cam element44corresponds to the upward-tilted position of the horizontal part of the forks2a,2b,2c,2d, for example such tilted position can be +5° of the horizontal part of the forks2a,2b,2c,2dwith respect to a horizontal plane.

In the configuration ofFIG.19, the cam element44is found in a lower end position, actuated by the first linear electric actuator8: such position of the cam element44corresponds to the downward-tilted position of the horizontal part of the forks2a,2b,2c,2d, for example such tilted position can be −5° of the horizontal part of the forks2a,2b,2c,2dwith respect to a horizontal plane.

The cam element44therefore allows multiplying the force developed by the first linear electric actuator8so as to attain a tilt of the forks2a,2b,2c,2dalso with one or two linear electric actuators, of commercial type that is not very bulky.

It is thus seen that the invention reaches the proposed objects.

In particular, the proposed solutions have systems for actuating the forks with limited size and limited weight, also due to the fact that the particular configurations proposed for the means for connecting the second frame to the first frame allow using actuators which operate with lower forces with respect to the known solutions.

The invention thus conceived is susceptible of numerous modifications and variations, all falling within the scope of the inventive concept.

In addition, all the details can be substituted by other technically equivalent elements. In practice, the materials employed, as well as the contingent shapes and sizes, can be of any type according to the requirements, without departing from the protective scope of the following claims