Material handling device and attachment assembly

Abstract

An attachment assembly comprises a suspension (10) for mounting on a carriage of a material handling device, such as particularly a fork-lift truck. The attachment assembly comprises a face plate (20) with a set of lifting members (22, 24). In order to enable the assembly to be displaced sideways as a whole the suspension comprises a first profile (15) which is intended and configured to hook onto the carriage, and a second profile (16) which is received slidably over the first profile. Provided between the first profile and the second profile is an actuator (12) which is able and configured to impose on the second profile a sideways displacement relative to the first profile. The actuator is mounted on the second profile and engages on the first profile via a recess (14) provided in the second profile. In order to enable sideways adjustment of the lifting members (22, 24) a set of linear actuators (32) can be coupled to a lifting member (22, 24) each.

Description

[0001] Material handling device and attachment assembly

[0002] The present invention relates to an attachment assembly for a material handling device, particularly for a transport and / or lifting vehicle, more particularly for a fork-lift truck, comprising a suspension for a carriage which is suspended for vertical movement in a mast of the material handling device, and comprising a face plate with at least one lifting member on which a load is receivable. The invention also relates to a material handling device which is equipped with such an attachment assembly.

[0003] An attachment assembly of the type described in the preamble is for instance known from International patent application WO 2021 / 142310. The face plate is connected via a frame assembly to the carriage of the lifting vehicle. The frame assembly is here connected to the carriage for sideways sliding and coupled to an actuator. This makes it possible to position the frame assembly, and thereby also the face plate connected thereto, sideways as a whole. The face plate in turn supports a set of lift forks which are each coupled to an actuator, whereby their mutual distance and position on the face plate can be changed. All in all, this results in a particularly practical attachment assembly which can always be adapted optimally to a load to be lifted therewith.A drawback of the known attachment assembly is however the depth taken up thereby relative to the mast of the vehicle. Although the actuators are accommodated in central cavities recessed in the frame assembly and the face plate for this purpose, the fact remains that the combination of the carriage, the frame assembly and the face plate takes up a significant distance. The centre of gravity of the load hereby lies further removed from the mast of the vehicle. The thereby increased tilting moment limits the maximum load-bearing capacity of the attachment assembly.

[0004] The present invention has for its object, among others, to provide an attachment assembly for a material handling device, particularly for a transport and / or lifting vehicle, more particularly for a fork-lift truck, which has a reduced attachment distance while maintaining functionality. In a further aspect the present invention has for its object, among others, to provide an attachment assembly for such a material handling device which provides increased safety for the driver.

[0005] In order to achieve the stated object an attachment assembly of the type described in the preamble has the feature according to the invention that the suspension comprises a first profile intended and configured to hook onto the carriage, that the suspension comprises a second profile which is receivedslidably over the first profile, that provided between the first profile and the second profile is an actuator which is able and configured to impose on the second profile a sideways displacement relative to the first profile, and that the actuator is mounted on the second profile and engages on the first profile, particularly via a recess provided in the second profile.

[0006] The suspension of the attachment assembly comprises here a set of profiles displaceable relative to each other. The first profile can be coupled fixedly to the carriage of the material handling device and the attachment assembly itself provides for an actuator between the two profiles for enabling a sideways displacement of the whole. The carriage of the material handling device thus requires no modification for this purpose.

[0007] This also saves on installation depth for the actuator in that the actuator is mounted on the second profile and engages on the first profile via the recess provided in the second profile. The space provided in the height by the attachment assembly is thus put to good use for thus limiting the horizontal attachment distance. For the actuator use is particularly made of a hydraulic pressure cylinder with a piston body which extends in linearly movable manner from a cylinder housing of the pressure cylinder, wherein the piston bodyengages on the first profile and the cylinder housing is connected firmly to the second profile.

[0008] A friction-reducing lining of plastic or another friction-reducing material, such as for instance also a relatively soft metal such as brass, preferably lies between the first profile and the second profile.

[0009] In a particular embodiment the attachment assembly has the feature according to the invention that the at least one lifting member is received slidably by a sideways guide, that each of the at least one lifting member is coupled to a further actuator which is able and configured to impose on the lifting member a displacement over the guide relative to the face plate, and that the guide extends above and at least partially behind the face plate.

[0010] By providing the sideways guide and the connection of the lifting member thereto above and at least partially behind the support instead of at the position of the face plate itself it is also possible to save on the installation depth which would otherwise be required therefor in the face plate. This installation depth is instead found in the space above and at least partially behind the face plate, this limiting the overall depth of the attachment assembly all the more and therebyhaving a positive effect on a location of the centre of gravity of a load taken up by the lifting member.

[0011] In a preferred embodiment the attachment assembly according to the invention is characterized here in that the face plate and the guide are arranged in a frame, wherein the guide, spatially separated from the face plate, extends between opposite flanks of the frame. The frame thus provides above and at least partially behind the face plate space for the guide and, with the flanks, a mounting base therefor, while the face plate is likewise mounted therein and supports the whole frame assembly.

[0012] In a further preferred embodiment the attachment assembly is characterized in that the further actuator is likewise arranged in the frame and engages on the lifting member between the face plate and the suspension. The space between the face plate and the suspension, i.e. distally behind the face plate, is here also utilized for placing the further actuator(s) in the frame whereby each of the at least one lifting member can be extended sideways. This also saves on attachment distance and moreover brings the overall weight of the guide with the at least one lifting member running thereover closer to the mast of the material handling device.For the further actuator(s) use can be made of a linear actuator, such as a screw spindle or a pneumatic or hydraulic pressure cylinder. Good results have been achieved in this respect with hydraulic pressure cylinder(s) with a piston body which extends in linearly movable manner from a cylinder housing of the pressure cylinder, wherein the piston body (piston rod) engages on the relevant lifting member. The assembly particularly comprises a set of identical lifting members, wherein each of the lifting members is coupled independently to a further actuator.

[0013] A preferred embodiment of the attachment assembly has the feature here according to the invention that the at least one lifting member comprises a holder with a lift fork held therein, and that the further actuator engages on the holder of the lift fork. The further actuators do not engage directly on the lift fork(s) here, but instead on a holder comprising the lift fork. The holder is in turn coupled to the guide and thus provides for a practical exchangability of the lift forks for longer or shorter ones or a different type thereof.

[0014] In a further preferred embodiment the attachment assembly has the feature according to the invention that the guide comprises an elongate pipe body, tube body or rod body which is connected to the opposite flanks of the frame on opposite outer ends, and that the holder of the lifting member comprises ahollow bushing which is closed all the way around and is movable over the guide therewith.

[0015] In a further particular embodiment the attachment assembly is characterized according to the invention in that the suspension is comprised by a back plate, that the face plate and the back plate are mutually connected via at least one electronic load cell, and that the at least one load cell is coupled to processing means for emitting an electronic output signal.

[0016] The attachment assembly is here coupled to the carriage of the material handling device via the back plate. The back plate in turn supports the face plate with the one or more lifting members. The mutual connection between the back plate and the face plate here absorbs the whole load as exerted on the at least one lifting member by a load. Weight information regarding the magnitude of this load is obtained by making use of one or more load cells for this purpose. The invention thus provides a weighing attachment assembly.

[0017] In a preferred embodiment the attachment assembly according to the invention has the feature here that the load cell comprises in each case a multidimensional load cell, which is able and configured to measure relative to a load on the face plate thereof in a first direction a first value and in at least onefurther direction at least one further value in order to generate and emit to the processing means separate output signals for each of the directions.

[0018] Such a multidimensional load cell for instance comprises for each of the detection directions a separate strain gauge from which is obtained an output voltage which is representative of the load in the measuring direction of the relevant strain gauge. In accordance with this embodiment these output signals are received separately to enable them to be processed separately by the processing means. In a particular embodiment the attachment assembly according to the invention is characterized here in that the directions are mutually orthogonal directions, particularly corresponding to a transverse direction and a height direction of the face plate.

[0019] Owing to the output signals being emitted and processed separately for the different measuring devices, valuable information is preserved. In a further preferred embodiment of the attachment assembly according to the invention this is utilized. For this purpose this embodiment is characterized in that the output signals are processed separately by the processing means into arithmetic values and that the processing means are able and configured to calculate therefrom a location of a centre of gravity of a load on the face plate. This information gives the driver insight into the actual location of the centre ofgravity of the load supported by the one or more lifting members relative to the face plate, both in a width direction but also in axial direction. This information is of utmost importance for safe manoeuvring, and particularly the estimation of a maximum safe lifting height therein.

[0020] With a view to further increased safety, a further preferred embodiment of the attachment assembly has the feature according to the invention that an electronic height sensor is provided therein, which is able and configured to measure a distance between the face plate and a ground surface and to emit an electronic signal corresponding therewith to the processing means, wherein the processing means are able and configured to determine a tilting moment of the material handling device from the at least one output signal of the at least one load cell and the output signal of the height sensor. The tilting moment is the moment of force of the load relative to the front axle of the material handling device, and increases the further forward and higher the centre of gravity of the load is located.

[0021] On the basis of the output signals of said sensors the processing means are able to determine and, if desired, monitor the tilting moment. When a value assessed as being the maximum safe value is exceeded, a warning can be given to the driver. For this purpose a further particular embodiment of the attachmentassembly has the feature according to the invention that the processing means are coupled to warning means and, together, are able and configured to emit a sensory warning signal when a safe tilting moment thereof is at risk of being exceeded.

[0022] In a particular embodiment the attachment assembly according to the invention is characterized here in that the height sensor comprises a sensor from a group comprising an ultrasonic sensor and a radar module, and particularly that the height sensor is accommodated between the face plate and back plate with an unobstructed view of the ground surface. Owing to this placement behind the face plate, the height sensor lies protected against a frontal impact in particular. The ultrasonic sensor or radar module requires a relatively small mounting volume, which can be found between the face plate and the back plate.

[0023] In a further preferred embodiment the attachment assembly according to the invention has the feature that the processing means comprise for each load cell a processing unit which is able and configured to process the separate output signals of the load cell coupled thereto into individual arithmetic values, that the processing units comprise a central processing unit, and that the processing units are coupled to each other for data exchange, wherein the central processing unit is able and configured to receive the individual arithmetic valuesfrom the remaining processing units and process them into one or more resultants.

[0024] Particularly, the individual processing units in each case comprise here a digital to analogue converter (DAC) whereby analogue output signals of the load cell coupled thereto are converted into digital arithmetic values and are in this form exchanged with the central processing unit. Such a data exchange is considerably less susceptible to disruption than an analogue transfer.

[0025] For an intuitive exchange of the values calculated by the central processing unit, such as particularly a location of the centre of gravity of a load, a lifting height and / or a tilting moment, a further particular embodiment of the attachment assembly has the feature according to the invention that the central processing unit is coupled or is at least connectable to a display device for exchange of the calculated resultants, and that the display device is able and configured to display the resultants in a manner allowing insight therein. Besides indicating a calculated value, this view can particularly comprise a graphic representation thereof which immediately provides the driver with the intended insight, optionally supported by a warning signal or other sensory stimulus.A material handling device, particularly a transport vehicle and / or lifting vehicle, more particularly a fork-lift truck, comprises a movable frame and supports according to the invention an attachment assembly according to one or more of the above described embodiments of the invention.

[0026] The invention will be further elucidated hereinbelow with reference to an exemplary embodiment and an accompanying drawing. In the drawing:

[0027] Figure 1 is a perspective front view of an exemplary embodiment of an attachment assembly according to the invention;

[0028] Figure 2 is a rear view of the attachment assembly of figure 1;

[0029] Figure 3 is a top view of the attachment assembly of figure 1;

[0030] Figure 4A is a side view of the attachment assembly of figure 1;

[0031] Figure 4B is a lateral section along the line IV- IV in figure 3 of the attachment assembly of figure 1; and

[0032] Figure 5 is a wiring diagram of the attachment assembly of figure 1.

[0033] It is otherwise noted here that the figures are purely schematic and not always drawn to (the same) scale. Some dimensions in particular may be exaggerated to greater or lesser extent for the sake of clarity. Corresponding parts are designated in the figures with the same reference numeral.Figure 1 shows a perspective frontal view of an embodiment of an attachment assembly for a material handling device, such as in this case a fork-lift truck. This is a standard fork-lift truck which is not shown in the drawing for the sake of clarity, but is assumed sufficiently known to a person with ordinary skill in the art. The drawn attachment assembly comprises a suspension 10 for a releasable coupling with the carriage of the fork-lift truck which is vertically moveable therein in a mast of the vehicle. The attachment assembly further comprises a face plate 20 with a support 25 which supports a set of lifting members for sideways displacement.

[0034] The lifting members comprise lift forks 22, also referred to as forks, which are each mounted in a holder 24 which runs over the support 25. The holders 24 hook around the face plate on both an upper side and an underside, see also figures 4A and 4B, and so ensure a moveable confinement of the lifting members around the face plate. The holders 24 comprise at their outer end a coupling part 26 in the form of a hollow bushing in which a guide 28 is slidingly received. The coupling parts 26 engage around the guide 28, whereby the holders 24 transmit a load on the lift forks 22 largely to the guide 28 and thus relieve and enhance the sideways movement over the face plate. In order to be able to withstand this load, use is made for guide 28 of a strong steel bar or tube, typically with a diameter in the order of 40 to 80 millimetres.The guide 28 extends above and at least partially behind the face plate 20 with the support 25 for the holders 24 of the lift forks 22. For this purpose use is made in the shown example of a frame assembly wherein the face plate 20 is arranged in a frame 30 surrounding it. The face plate 20 is fastened rigidly in the frame 30 by means of bolts and nuts. The guide 28 is likewise received, spatially separated from the face plate 20, in the frame and extends here from flank to flank of the frame. The frame assembly optionally further also comprises a head board 35 whereby the frame assembly is extended in height direction for the purpose of receiving loads having a great height. This head board 35 is connected to each of the flanks of the frame 30 by means of screw bolts, and can thus be placed or removed in simple manner.

[0035] The frame 30 moreover provides space and a mounting base for a set of actuators 32 whereby the holders 24 and thereby the lift forks 22 can be extended sideways relative to the face plate 20. For this purpose use is made in this example of hydraulic pressure cylinders which can be received in a hydraulic circuit with a hydraulic pump of the vehicle. For each of the holders such a pressure cylinder 32 is mounted between a flank of the frame 30 and the relevant holder 24, wherein an extending piston rod 33 of the cylinder 32 engages distally on a central point of engagement 27 on the coupling part 26 of the holder 24. This is shown in top view in figure 3, while figure 2 shows this in arear view. Each of the holders 24, and thereby the lift forks 22, can be extended sideways individually by means of the hydraulic cylinders 32 in the frame 30. A mutual distance and collective positioning relative to the face plate 20 of the lifting members 22 can hereby be adjusted using the cylinders 32.

[0036] The attachment assembly is moreover extendable sideways as a whole relative to the mast of the vehicle. For this purpose the suspension 10 comprises a first profile 15, see figures 4A and 4B, which provides for a fixed connection to the vertically movable carriage in the mast of the vehicle. A second profile 16 slides thereover via a friction-reducing lining 17, see figure 3, of plastic or another friction-reducing material, such as for instance also a relatively soft metal such as brass. A linear actuator 12, such as in this case a hydraulic pressure cylinder, is placed between the two profiles 15, 16 of the suspension 10. The cylinder 12 is here mounted on top of the second profile 16, see figures 4A and 4B, and engages via a recess 14 in the second profile 16 on the first profile 15 which lies thereunder and is connected or can at least be connected firmly to the carriage, see figure 3.

[0037] The actuator 12 thus forms part of the attachment assembly and the vehicle requires no substantial modification therefor. Extending the cylinder 12 brings about a sideways displacement of the second profile 16 over the first profile 15.Because the second profile 16 is coupled rigidly to the face plate 20, the face plate 20 will thereby shift sideways, and with this the lifting members 22 supported thereby, which will thus be displaceable to the left or the right together.

[0038] In this example the suspension 10 is connected to the face plate 20 via a back plate 40. For a rigid connection between the back plate 40 and the face plate 20 use is made here of four load cells 41..44 at the corners of the two plates 20, 40. These are so-called multi-dimensional load cells 41..44 which are able and configured to separately determine and emit as electronic signal a component of the load in separate directions. In this respect the sensors 41..44 applied here produce in two orthogonal directions x,y an analogue output signal Vx,Vy corresponding with a load in sideways direction x and in vertical direction y.

[0039] Figure 5 shows schematically a wiring diagram of the load cells 41..44. Each of the sensors 41..44 is coupled individually to a processing unit 51..54 which, besides providing for an electric power supply of the sensor coupled thereto, also provides for a conversion from analogue to digital of the load values Vx, Vy received therefrom. Although the sensors 41..44 and the processing units 51..54 are drawn as separate components in the figure, the processing units can also in each case be integrated into a single component with the correspondingsensors. The digital arithmetic values Lx, Ly obtained therefrom are shared via a joint digital bus connection 55 with a central processing unit 54 which takes on a further processing using the individual values Lx,Ly received from the other processing units 51..53 and the output signals Vx,Vy of the sensor 44 coupled directly thereto.

[0040] Because the two analogue part-signals Vx,Vy are essentially received separately and digitized individually, it is possible also to deduce therefrom a location of the centre of gravity of the load, this in addition to a magnitude of the load. The central processing unit 54 calculates this location of the centre of gravity Mx,My of a load supported by the lift forks 22 from the obtained information. This information is shown graphically on a screen 60 in the cab of the vehicle in a manner which gives the driver immediate insight. Depending on the magnitude of the weight of the load, but also on the location and height of the centre of gravity of the load, a maximum allowable, in other words safe, lifting weight is determined. The maximum allowable load decreases the higher the load is lifted. This is shown by a load diagram. Using the values obtained from the sensors 41..44, this load diagram can be recalculated dynamically depending on the location of the centre of gravity of the load, and likewise be displayed on the screen 60. The driver can read the maximum lifting height therefrom and, if this height is exceeded, a sensory alarm signal can be emitted to the driver. Thismakes a significant contribution toward the safety of the material handling device.

[0041] Although the invention has been further elucidated above with reference to only a single exemplary embodiment, it will be apparent that the invention is by no means limited thereto. On the contrary, many variations and embodiments are still possible within the scope of the invention for a person with ordinary skill in the art. In the exemplary embodiment use is thus made of a face plate assembly, comprising the face plate and a separate frame which is connected to the face plate and which provides space to the guide and actuators for the lifting members. An independent face plate, which is extended upward in order to provide space to the guide, optionally in combination with the actuators, can instead also be applied. These latter can optionally also be provided between the face plate (assembly) and the suspension.

Claims

Claims:

1. Attachment assembly for a material handling device, particularly for a transport and / or lifting vehicle, more particularly for a fork-lift truck, comprising a suspension for a carriage which is suspended for vertical movement in a mast of the material handling device, and comprising a face plate with at least one lifting member on which a load is receivable, characterized in that the suspension comprises a first profile intended and configured to hook onto the carriage, that the suspension comprises a second profile which is received slidably over the first profile, that provided between the first profile and the second profile is an actuator which is able and configured to impose on the second profile a sideways displacement relative to the first profile, and that the actuator is mounted on the second profile and engages on the first profile, particularly via a recess provided in the second profile.

2. Attachment assembly according to claim 1, characterized in that the actuator comprises a hydraulic pressure cylinder with a piston body which extends in linearly movable manner from a cylinder housing of the pressure cylinder, wherein the piston body engages on the first profile and the cylinder housing is connected firmly to the second profile.

3. Attachment assembly according to claim 1 or 2, characterized in that a friction-reducing lining, particularly of plastic or another friction-reducing material, such as a relatively soft metal such as brass, is included between the first profile and the second profile.

4. Attachment assembly according to claim 1, 2 or 3, characterized in that the at least one lifting member is received slidably by a guide extending in a width direction, that each of the at least one lifting member is coupled to a further actuator which is able and configured to impose on the lifting member a displacement over the guide relative to the face plate, and that the guide extends above and at least partially behind the face plate.

5. Attachment assembly according to one or more of the preceding claims, characterized in that the face plate and the guide are arranged in a frame, wherein the guide, spatially separated from the face plate, extends between opposite flanks of the frame.

6. Attachment assembly according to claim 5, characterized in that the further actuator is likewise arranged in the frame and engages on the lifting member between the face plate and the suspension.

7. Attachment assembly according to claim 6, characterized in that the at least one lifting member comprises a holder with a lift fork held therein, and that the further actuator engages on the holder of the lift fork.

8. Attachment assembly according to claim 7, characterized in that the guide comprises an elongate pipe body, tube body or rod body which is connected to the opposite flanks of the frame on opposite outer ends, and that the holder of the lifting member comprises a hollow bushing which is closed all the way around and is movable over the guide therewith.

9. Attachment assembly according to one or more of the preceding claims, characterized in that the suspension is comprised by a back plate, that the face plate and the back plate are mutually connected via at least one electronic load cell, and that the at least one load cell is coupled to processing means for emitting an electronic output signal.

10. Attachment assembly according to claim 9, characterized in that the load cell comprises in each case a multidimensional load cell, which is able and configured to measure relative to a load on the face plate thereof in a first direction a first value and in at least one further direction at least one furthervalue in order to generate and emit to the processing means separate output signals for each of the directions.

11. Attachment assembly according to claim 10, characterized in that the directions are mutually orthogonal directions, particularly corresponding to a transverse direction and a height direction of the face plate.

12. Attachment assembly according to claim 10 or 11, characterized in that the output signals are processed separately by the processing means into arithmetic values and that the processing means are able and configured to calculate therefrom a location of a centre of gravity of a load on the face plate.

13. Attachment assembly according to claim 9, 10, 11 or 12, characterized in that an electronic height sensor is provided therein, which is able and configured to measure a distance between the face plate and a ground surface and to emit an electronic signal corresponding therewith to the processing means, wherein the processing means are able and configured to determine a tilting moment of the material handling device from the at least one output signal of the at least one load cell and the output signal of the height sensor.

14. Attachment assembly according to claim 13, characterized in that the processing means are coupled to warning means and, together, are able and configured to emit a sensory warning signal when a safe tilting moment thereof is at risk of being exceeded.

15. Attachment assembly according to claim 13 or 14, characterized in that the height sensor comprises a sensor from a group comprising an ultrasonic sensor and a radar module, and that the height sensor is accommodated between the face plate and back plate with an unobstructed view of the ground surface.

16. Attachment assembly according to one or more of the claims 9-15, characterized in that the processing means comprise for each load cell a processing unit which is able and configured to process the separate output signals of the load cell coupled thereto into individual arithmetic values, that the processing units comprise a central processing unit, and that the processing units are coupled to each other for data exchange, wherein the central processing unit is able and configured to receive the individual arithmetic values from the remaining processing units and process them into one or more resultants.

17. Attachment assembly according to claim 16, characterized in that the central processing unit is coupled or is at least connectable to a display device for exchange of the calculated resultants, and that the display device is able and configured to display the resultants in a manner allowing insight therein.

18. Material handling device, particularly a transport vehicle and / or lifting vehicle, more particularly a fork-lift truck, comprising a movable frame and an attachment assembly according to one or more of the preceding claims.

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