EP3168185B1 - Industrial truck with a lifting frame with a lifting mast - Google Patents

Description

The invention relates to an industrial truck with a lifting frame which comprises a lifting mast, the lifting frame being provided with a lifting device that can be raised and lowered and the lifting mast has two laterally spaced profile rails which are connected to one another by means of at least one cross member, the cross member being X-shaped , which consists of a central area arranged between the profile rails and struts which extend in an X-shape from the central area to the profile rails and are fastened to the profile rails, a see-through opening being formed between the central area and two struts which extend to one of the two profile rails which extends up to one of the two profile rails, wherein a lifting carriage provided with the load-bearing means is arranged in the profile rails so as to be longitudinally displaceable.

Such lifting masts are used in the lifting frames of industrial trucks, for example counterbalanced forklifts. Known masts can be used as a standing mast of a single-section mast (so-called simplex mast) or as an extending mast of a multi-section mast, for example a duplex mast, which consists of a standing mast and an extending mast, or a triplex mast, which consists of a standing mast and two extending masts be trained.

The two laterally spaced profile rails of such lifting masts are usually connected to one another by means of at least two cross members. The area between the two profile rails then forms a see-through area through the lifting mast, through which an operator located in a driver's workstation of the industrial truck can see a load handling device that can be raised and lowered on the profile rails of the lifting mast.

Here, designs of lifting masts are known in which the two laterally spaced profile rails of the lifting mast are connected to one another by means of at least three cross members. A first cross member is designed as a foot cross member, which is arranged in the foot area of the profile rails. Another cross member is designed as a head cross member which is arranged in the head area of the profile rails. At least one further cross member is designed as a central cross member, which is arranged in the vertical direction of the lifting mast between the foot cross member and the head cross member. When the lifting mast is designed as a liftable and lowerable extending mast of a multi-section mast, the raised or lowered central cross member, depending on the lifting position of the extending mast and thus at different lifting heights of a lifting device of the lifting mast, obstructs the view of an operator in a driver's workstation of the industrial truck.

In known lifting masts, the cross member is designed as a solid component, for example as a steel plate. Such a massive component as a cross member, however, leads to a great obstacle to the operator of the industrial truck's view of the load handling device.

In order to reduce the visibility of the truck operator on the load handling device, it is already known to create see-through openings at places where there is little stress on the cross member, which is formed by a solid component, for example a substantially rectangular steel plate. A lifting mast with a massive cross member, which is provided with such see-through openings, is for example from the WO 2014/124932 A1 known. Even with a cross member that is provided with such see-through openings, however, the operator of the industrial truck still hinders the view of the load suspension device at different lifting heights of a load suspension device of the lift mast, since the load suspension device is covered by the cross beam. The operator must therefore move the head and / or the upper body correspondingly strong in order to get a view of the load suspension device over the cross member or under the cross member.

the DE 26 17 785 A discloses a lifting frame of an industrial truck, with an extendable inner mast, an extendable central mast and an outer mast designed as a standing mast. A lifting cylinder is supported on a lower cross member of the central mast. A lifting carriage is arranged in the inner mast so that it can be raised. Of the The inner mast has two vertical profile rails that are connected to one another by a cross-shaped (X-shaped) cross member. the CN 201 670 699 U discloses a lift mast with an X-shaped cross member.

The present invention is based on the object of providing an industrial truck with a lifting frame, which has a lifting mast of the type mentioned at the outset, which, due to its shape, enables an operator of the industrial truck to have an improved view of the load handling device.

This object is achieved according to the invention in that the lifting mast for raising and lowering the lifting carriage in the profile rails is provided with a lifting cylinder device, the lifting cylinder device being in operative connection with a lifting means which is attached to the lifting carriage with a first end and a second end is attached to the lifting mast and is deflected on the lifting cylinder device, wherein the lifting cylinder device is supported on the X-shaped cross member. An X-shaped cross member leads to an improved view of an operator through the lifting mast, since an X-shaped cross member forms a viewing opening on the side of the central area, which increases in height in the transverse direction of the lifting mast from the central area to the corresponding profile rail in the vertical direction and extends in the transverse direction of the mast up to the profile rail. Such see-through openings on the X-shaped cross member, which extend up to the profile rails and increase in height in the transverse direction of the lifting mast to the profile rails, lead to an improved view through the cross member and enable those located on the driver's workstation and looking at the load handling device Operator a maximum field of vision of the load suspension device, in which the view of the load suspension device is only minimally impaired by the cross member. The lifting mast according to the invention thus enables the operator of the industrial truck to have an improved view of the load handling device. The lifting mast according to the invention also leads to improved ergonomics for the operator of the industrial truck, since the operator only has to move the head and / or the upper body minimally through the improved view through the X-shaped cross member in order to have a view of the through the cross member Obtain load handling equipment. The X-shaped cross member according to the invention also forms the function a fastening point of the lifting cylinder device and, if necessary, also the function of preventing the lifting cylinder device from buckling.

According to a preferred embodiment of the invention, the cross member has a first strut that rises from the central area in the vertical direction to the first profile rail and is attached to the first profile rail, a second strut that slopes down from the central area in the vertical direction to the The first profile rail runs and is attached to the first profile rail, a third strut that rises from the central area in the vertical direction to the second profile rail and is attached to the second profile rail, and a fourth strut that extends from the central area in the vertical direction slopes down to the second profile rail and is attached to the second profile rail. With four such struts, which extend from the central area to the two profile rails, an X-shaped cross member with two large see-through openings can be formed with little construction effort, which are each arranged to the side of the central area. The upward and downward struts of the X-shaped crossbeam also increase the height of the crossbeam at the outer ends of the crossbeams and thus in the area of the profile rails. The increased height of the cross member at the outer ends of the cross struts leads to lower component stresses in the event of bending loads, so that the struts can be reduced in mass and thus in cross section, which also has a beneficial effect on an improved view through the lifting mast to the load handling device.

Advantageously, the struts are each fastened separately from one another to the profile rails by means of their own fastening interfaces. By means of a separate and therefore separate fastening of the four X-shaped struts, the crossbeam can be fastened to the two profile rails with little construction effort. The cross member according to the invention is thus designed to be open at the outer ends of the struts, the two struts that delimit a see-through opening in each case not being connected to one another at the outer ends.

With regard to an improved view through the lifting mast to the load suspension means, there are further advantages if, according to a development of the invention, an upper side of the struts at least partially from the The side of the lifting mast facing away from the load rises to the side of the lifting mast facing the load and an underside of the struts is at least partially sloping from the side of the lifting mast facing away from the load to the side of the lifting mast facing the load. This achieves a cross-sectional shape of the struts in which the front side of the struts facing away from the load has a lower height in the vertical direction than the rear side of the struts facing the load. The cross-sectional shape of the struts is therefore also optimized for visibility, since the underside of the struts is in the line of sight of the operator in the driver's workplace when the operator looks down, and the top of the struts is in the line of sight of the operator in the driver's workplace when the operator looks up Operator lies.

According to an advantageous embodiment of the invention, the lifting means is attached to the cross member. The cross member thus continues to function as a holder for the lifting means.

The lifting cylinder device is expediently arranged between the profile rails, in particular essentially in the middle between the profile rails. In this case, the lifting cylinder device is advantageously supported on the central area of the crossbeam and / or the lifting means is attached to the central area of the crossbeam.

The X-shaped cross member according to the invention can be designed in one piece and thus consist of one component.

Such a one-piece cross member is advantageously designed as a forged component or as a cast steel component.

Alternatively, such a one-piece cross member can be designed as a shaped sheet metal part. Such a cross member can be produced from a steel plate by bending, for example pressing, or cutting out, for example laser cutting or flame cutting.

The X-shaped cross member according to the invention can alternatively be constructed in several pieces and thus be composed of several components.

For this purpose, the cross member is expediently composed of the central area and the struts, the struts being attached to the central area by welded connections or screw connections.

In the case of a multi-piece cross member, the central area can be designed as a forged component or as a cast steel component.

The four struts can each be formed from a single component that is attached to the central area. Advantages in terms of cheap production arise when the first strut and the second strut are formed by a first shaped sheet metal part and the third strut and the fourth strut are formed by a second shaped sheet metal part, the two shaped sheet metal parts being attached to the central area by welded connections or screw connections. The shaped sheet metal parts can be produced from a steel plate by cutting out, for example laser cutting or flame cutting.

According to an advantageous embodiment of the invention, the load handling device is designed as a load fork with two fork prongs, the viewing openings on the cross member allowing an operator located in a driver's workplace of the industrial truck to see the fork prong tips of the fork prongs in the fully lowered position of the load handling device.

The lifting mast according to the invention can be designed as a standing mast of a single-section lifting frame.

Alternatively, the lifting mast according to the invention can be designed as an extending mast of a multi-section lifting frame. The X-shaped cross member on a lifting mast designed as an extendable mast enables an operator of the industrial truck to have an improved view of the load handling device at different lift heights of the extendable mast and thus of the load handling device.

Figur 1

einen Ausschnitt eines Hubmastes des Standes der Technik,

Figur 2

einen Ausschnitt eines Hubmastes des Standes der Technik, bei dem der Querträger mit Durchsichtöffnungen versehen ist,

Figur 3

den Hubmast der Figur 1 mit einem Blick einer Bedienperson des Flurförderzeugs auf das vollständig abgesenkte Lastaufnahmemittel,

Figur 4

einen Ausschnitt eines erfindungsgemäßen Hubmastes,

Figur 5

den Hubmast der Figur 4 mit einem Blick einer Bedienperson des Flurförderzeugs auf das vollständig abgesenkte Lastaufnahmemittel und

Figur 6

eine perspektivische Darstellung einer alternativen Ausführungsform eines erfindungsgemäßen Hubmastes.

Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiments shown in the schematic figures. Here shows

Figure 1

a section of a prior art lifting mast,

Figure 2

a section of a lifting mast of the prior art, in which the cross member is provided with see-through openings,

Figure 3

the mast of the Figure 1 at a glance of an operator of the industrial truck on the completely lowered load handler,

Figure 4

a section of a mast according to the invention,

Figure 5

the mast of the Figure 4 at a glance of an operator of the industrial truck on the completely lowered load handling device and

Figure 6

a perspective view of an alternative embodiment of a lifting mast according to the invention.

In the Figures 1 to 3 each shows a mast 1 of a mast of an industrial truck of the prior art. In the Figures 1 to 3 the lifting mast 1 is designed as an extending mast, for example an inner mast, of a multi-section lifting frame, for example a duplex lifting frame or a triplex lifting frame.

The mast 1 of the Figures 1 to 3 has two laterally spaced profile rails 2a, 2b in the transverse direction QR of the lifting mast 1. The two profile rails 2a, 2b are connected to one another by means of several cross members 3. In the Figures 1 to 3 a vertically central area of the lifting mast 1 is shown in each case. A lower cross member, not shown in detail, is arranged in the vertically lower foot area of the two profile rails 2a, 2b and is designed as a foot cross member. The cross member 3 shown is spaced from the foot cross member in the vertical direction VR of the lifting mast 1 and is designed as a central cross member 3a. Not shown in detail is an upper cross member which is arranged in the vertically upper head area of the two profile rails 2a, 2b and is designed as a head cross member. The cross member 3 is preferably connected to the profile rails 2a, 2b by welded connections.

In the two profile rails 2a, 2b, a lifting carriage, not shown, is arranged to be longitudinally displaceable, i.e. can be raised and lowered. The lifting carriage is provided with a load handling device, which is formed, for example, by a load fork with two fork prongs.

The lifting mast 1 is provided with a lifting cylinder device 5 for raising and lowering the lifting carriage. In the illustrated embodiment, the lifting cylinder device 5 is formed by a single lifting cylinder 5a, which has a cylinder housing 6, which is attached to the lifting mast 1, and an extendable and retractable one Has piston rod 7. The lifting cylinder 5a is arranged vertically and in the illustrated embodiment in the transverse direction QR of the lifting mast 1 between the two profile rails 2a, 2b, preferably essentially centrally between the two profile rails 2a, 2b. The lifting cylinder 5a is supported with the cylinder housing 6 on the foot cross member in a manner not shown in more detail in the vertical direction.

The lifting cylinder device 5 is in operative connection with a lifting means 10. The lifting means 10 is designed as a lifting chain 11 in the illustrated embodiment. The lifting means 10 is fastened with a first end to the lifting carriage in a manner not shown in detail. The lifting means 10 is fastened to the central cross member 3a of the lifting mast 1 by a second end 10b. In the Figures 1 to 3 the lifting means 10 designed as a lifting chain 11 is provided at the second end 10b with a chain anchor 12, which is guided through a receiving bore in the central cross member 3a and is attached to the central cross member 3a via a fastening means 13, in the illustrated embodiment a screw connection.

The lifting means 10 is deflected between the two ends 10a, 10b on the lifting cylinder device 5. For this purpose, the extending or retracting piston rod 7 of the lifting cylinder 5a is provided with a deflection roller 15 which is rotatably mounted about an axis of rotation 16 running in the transverse direction QR of the lifting mast 1. The lifting means 10 is guided over the deflection roller 15 for deflection.

The central cross member 3a also forms an upper support for the lifting cylinder device 5. The lifting cylinder device 5 is attached to the central cross member 3a, for example with a clamp 20 that encompasses the cylinder housing 6 or a cylinder head of the cylinder housing, as in FIG Figure 3 is shown in more detail. The central cross member 3a thus continues to have the function of a further fastening point of the lifting cylinder device 5 and the function of securing the lifting cylinder device 5 from buckling.

The mast 1 of the Figures 1 to 3 Thus, the cross member 3 designed as a central cross member 3a takes over the function of an abutment to the chain anchor 12 for fastening the lifting means 10 and as a buckling protection of the lifting cylinder device 5.

The lifting cylinder device 5 is in the Figures 1 to 3 thus designed as a free lift cylinder, with which the load handling device in the lifting mast 1, which is designed as an extendable mast, can be completely raised before the lifting mast, which is designed as an extending mast, is raised in a stationary mast of a duplex mast or a further extending mast of a triplex mast.

The area between the profile rails 2a, 3b forms a see-through area 25 of the lifting mast 1 through which an operator located in a driver's workstation of the industrial truck, for example a counterbalanced forklift, can see the load handling device.

In the Figures 1 to 3 the cross member is designed as a solid, plate-shaped component, which is fastened at the two outer ends to the profile rails 2a, 2b of the lifting mast 1 by a welded connection. The forces exerted by the lifting means 10 on the cross member 3 are introduced into the profile rails 2a, 2b via the cross member 3 and the weld seams of the welded connections. The shape of the cross member 3 depends on the component stresses and the stresses in the weld seams with which the cross member 3 is welded to the profile rails 2a, 2b in order to achieve the required fatigue strength.

In the Figure 2 a cross member 3 of a lifting mast 1 of the prior art, which is designed as a central cross member 3a, is shown, which is also formed as a solid, plate-shaped component and is provided with small see-through windows 26a, 26b at points that are little loaded by the flow of force in the cross member 3. The see-through windows 26a, 26b are formed by recesses in the massive and plate-like cross member 3, which in the Figure 2 are indicated by hatching. With the see-through windows 26a, 26b in the solid and plate-like cross member 3, the view through the cross member 3 can be improved.

In a lifting mast 1 of the prior art with cross members 3 of the Figures 1 and 2 However, it is disadvantageous that an operator located on the driver's workstation of the industrial truck at different lift heights of the mast 1 and thus of the load handling device, the fork tips of the fork prongs of a load handling device designed as a load fork in normal posture and with normal Can not see the direction of view, since the fork prong tips of the fork prongs are covered by the massive and plate-shaped cross member 3.

In the Figure 3 is this on the mast 1 of the Figure 1 made clear. In the Figure 3 the mast 1 is shown with the load handling device fully lowered. The load handling device is designed as a load fork with two fork prongs, one of which is in the Figure 3 a right fork prong 30 is shown. In the Figure 3 the field of view of an operator located at the driver's workstation of the industrial truck with a normal posture and with a normal viewing direction at the fork prong 30 is shown. In this lifting position of the load suspension device, the fork prong tip of the fork prong 30 is covered by the cross member 3 so that the operator cannot see the fork prong tip with a normal posture and normal viewing direction. Even with an embodiment of the cross member 3 of the Figure 2 with see-through windows 26a, 26b there is likewise no significant improvement in the view of the operator of the industrial truck on the fork prongs and the fork prong tips. In a lifting mast 1 of the prior art, the operator must move the head and / or the upper body correspondingly strong in order to get a view of the fork prong tip of the fork prong 30 over the cross member 3 or under the cross member 3. However, this leads to poor ergonomics for the operator of the industrial truck.

For the orientation of the operator of the industrial truck, however, the fork prong tips of the fork prongs 30 are an essential factor.

In the Figures 4 to 6 an inventive mast 1 of a mast of an industrial truck is shown in each case. With the Figures 1 to 3 the same components are provided with the same reference numbers. the Figure 4 branches a first embodiment and the Figure 6 a second embodiment of a lifting mast 1 according to the invention.

In the Figures 4 to 6 the lifting mast 1 is designed as an extending mast, for example an inner mast, of a multi-section lifting frame, for example a duplex lifting frame or a triplex lifting frame.

The mast 1 of the invention Figures 4 to 6 has two laterally spaced profile rails 2a, 2b in the transverse direction QR of the lifting mast 1. The two Profile rails 2a, 2b are connected to one another by means of several cross members 3. In the Figures 4 and 5 a vertically central area of a lifting mast 1 according to the invention is shown in each case. the Figure 6 shows the lower and middle area of a lifting mast 1 according to the invention Figure 6 The lower cross member 4 shown is arranged in the vertically lower foot area of the two profile rails 2a, 2b and is designed as a foot cross member 4a. The one in the Figures 4 to 6 The cross member 3 shown is spaced from the foot cross member 4a in the vertical direction VR of the lifting mast 1 and is designed as a central cross member 3a. Not shown in detail is an upper cross member which is arranged in the vertically upper head area of the two profile rails 2a, 2b and is designed as a head cross member. The cross member 3 and the cross member 4 are preferably connected to the profile rails 2a, 2b by welded connections.

In the two profile rails 2a, 2b, a lifting carriage, not shown, is arranged to be longitudinally displaceable, i.e. can be raised and lowered. The lifting carriage is provided with a load handling device, which is formed, for example, by a load fork with two fork prongs.

The lifting mast 1 is provided with a lifting cylinder device 5 for raising and lowering the lifting carriage. In the exemplary embodiment shown, the lifting cylinder device 5 is formed by a single lifting cylinder 5 a, which has a cylinder housing 6 that is fastened to the lifting mast 1 and an extendable and retractable piston rod 7. The lifting cylinder 5a is arranged vertically and in the illustrated embodiment in the transverse direction QR of the lifting mast 1 between the two profile rails 2a, 2b, preferably essentially centrally between the two profile rails 2a, 2b. The lifting cylinder 5a is - as in the Figure 6 is shown in more detail - supported with the cylinder housing 6 on the foot cross member 4 in the vertical direction.

The lifting cylinder device 5 is in operative connection with a lifting means 10. The lifting means 10 is designed as a lifting chain 11 in the illustrated embodiment. The lifting means 10 is attached to the lifting slide with a first end 10a in a manner not shown in detail. The lifting means 10 is fastened to the central cross member 3a of the lifting mast 1 by a second end 10b. In the Figures 4 to 6 is designed as a lifting chain 11 lifting means 10 at the second end 10b with a Chain anchor 12 is provided, which is guided through a receiving bore in the central cross member 3a and is fastened to the central cross member 3a via a fastening means 13, in the illustrated embodiment a screw connection.

The lifting means 10 is deflected between the two ends 10a, 10b on the lifting cylinder device 5. For this purpose, the extending or retracting piston rod 7 of the lifting cylinder 5a is provided with a deflection roller 15 which is rotatably mounted about an axis of rotation 16 running in the transverse direction QR of the lifting mast 1. The lifting means 10 is guided over the deflection roller 15 for deflection.

The central cross member 3a also forms an upper support for the lifting cylinder device 5. The lifting cylinder device 5 is attached to the central cross member 3a, for example with a clamp 20 that encompasses the cylinder housing 6 or a cylinder head of the cylinder housing, as in FIG Figure 5 is shown in more detail. The central cross member 3a thus continues to have the function of a further fastening point of the lifting cylinder device 5 and the function of securing the lifting cylinder device 5 from buckling.

The mast 1 of the Figures 4 to 6 Thus, the cross member 3 designed as a central cross member 3a takes over the function of an abutment to the chain anchor 12 for fastening the lifting means 10 and as a buckling protection of the lifting cylinder device 5.

The lifting cylinder device 5 is in the Figures 4 to 6 designed as a free-lift cylinder, with which the load-handling device in the lifting mast 1, which is designed as an extendable mast, can be completely raised before the lifting mast, which is designed as an extending mast, is raised in a stationary mast of a duplex mast or a further extending mast of a triplex mast.

The area between the profile rails 2a, 3b forms a see-through area 25 of the lifting mast 1, through which an operator located in a driver's workstation of the industrial truck, for example a counterbalanced forklift, can see the load handling device.

In the mast 1 of the invention Figures 4 to 6 the cross member 3 formed as a central cross member 3a is X-shaped. The cross member 3 having the shape of an X consists of a central area 40 arranged between the profile rails 2a, 2b and struts 41-44 which extend in an X-shape from the central area 40 to the profile rails 2a, 2b and are fastened to the profile rails 2a, 2b. Between the central area 40 and two struts 41, 42 or 43, 44, which extend to one of the two profile rails 2a or 2b, a see-through opening 45a, 45b is formed, which extends in the transverse direction QR of the lifting mast 1 from the central area 40 extends up to the corresponding profile rail 2a, 2b.

The cross member 3 according to the invention has a first strut 41, which rises from the central area 40 in the vertical direction to the first profile rail 2a and is attached to the first profile rail 2a, and a second strut 42, which extends from the central area 40 in the vertical direction slopes down to the first profile rail 2a and is attached to the first profile rail 2a. The see-through opening 45a is formed between the central area 40, the two struts 41, 42 and the profile rail 2a. The cross member 3 according to the invention furthermore has a third strut 43 which rises from the central area 40 in the vertical direction to the second profile rail 2b and is attached to the second profile rail 2b, and a fourth strut 44 which extends from the central area 40 in the vertical direction Direction sloping to the second profile rail 2b and is attached to the second profile rail 2b. The see-through opening 45b is formed between the central area 40, the two struts 43, 44 and the profile rail 2b.

The struts 41-44 extend from the central area 40 outward in the direction of the profile rails 2a, 2b in such a way that the see-through openings 45a, 45b on the central area 40 form a rounded, in particular circular, transition 46a, 46b. Such a transition 46a, 46b has a favorable effect on the component stresses caused by the flow of force in the cross member 3.

In the laterally outer area on the profile rails 2a, 2b, the see-through openings 45a, 45b have a height extension in the vertical direction VR that is greater than the maximum height extension of the central region 40 in the vertical direction VR.

The struts 41-44 are fastened at the outer ends separately from one another on the profile rails 2a, 2b of the lifting mast 1 by means of their own fastening interface BF1-BF4. The struts 41-44 are thus each attached to the profile rails 2a, 2b independently of one another. The struts 41-44 are preferably fastened at the outer ends to the corresponding profile rail 2a or 2b by a welded connection with corresponding welded seams. The cross member 3 according to the invention is thus designed to be open at the outer ends of the struts 41-44. The struts 41 and 42 have no connection to one another at the outer ends. Correspondingly, the struts 43 and 44 have no connection to one another at the outer ends.

The struts 41-44 are arranged inclined upwards or downwards in such a way that the cross member 3 according to the invention compared to a cross member 3 of the prior art at the outer areas where the cross member 3 is connected to the profile rails 2a, 2b, a has increased height H in the vertical direction. The cross member 3 according to the invention preferably has a ratio H / B of the height H to the lateral distance B of the two profile rails of greater than or equal to 0.65. By increasing the height H at the outer ends of the cross member 3, two narrow struts 41, 42 and 42, 43 can be placed on each side of the cross member 3 according to the invention instead of a solid web of the cross member 3 of the prior art ( Figures 1 to 3 ) are used, so that two correspondingly large see-through openings 45a, 45b are created, which result in an improved view through the cross member 3 according to the invention.

In the embodiment of Figures 4 and 5 An upper side 50 of the struts 41-44 is at least partially designed to rise from the side of the lifting mast 1 facing away from the load to the side of the lifting mast 1 facing the load, and an underside 51 of the struts 41-44 at least partially from the side of the lifting mast 1 facing away from the load to the side of the lifting mast 1 facing the load arranged sloping. The struts 41-44 thus have at least partially on the front side 52 of the struts 41-44 facing away from the load in the vertical direction VR a lower height HV (thickness of the struts 41-44) than the height HH (thickness of the struts 41-44) on the rear side 53 of the struts 41-44 facing the load.

In the lifting mast 1 according to the invention, the lifting cylinder device 5 is supported on the central region 40 of the cross member 3 and the lifting means 10 is fastened to the central region 40 of the cross member 3. For this purpose, the lifting cylinder device 5 is fastened to the central region 40, for example with the clamp 20 which encompasses the cylinder housing 6 or a cylinder head of the cylinder housing 6, as in FIG Figure 5 is shown in more detail. The lifting means 10 designed as a lifting chain 11 is provided with a chain anchor 12 at the second end 10b, which is guided through a receiving bore in the central region 40 and is fastened to the central region 40 via a fastening means 13, in the illustrated embodiment a screw connection.

In the embodiment of Figures 4 and 5 the cross member 4 according to the invention is formed in one piece. The cross member 3 consisting of the central area 40 and the four struts 41-44 is preferably designed as a forged component or as a cast steel component. The struts 41-44 are preferably each fastened to the profile rails 2a, 2b of the lifting mast 1 by a welded connection.

In the embodiment of Figure 6 , in which a further embodiment of the invention is shown, cross member 3 is formed in several pieces. The cross member 3 of the Figure 6 is composed of a component that forms the central area 40, and further components that form the struts 41-44. The components forming the struts 41-44 can be attached to the component forming the central area 40 by welded connections or screw connections.

The component forming the central region 40 is preferably designed as a forged component or as a cast steel component.

In the Figure 6 the first strut 41 and the second strut 42 are formed by a first shaped sheet metal part 60. The third strut 43 and the fourth strut 44 are formed by a second shaped sheet metal part 61. The two shaped sheet metal parts 60, 61 are fastened to the component that forms the central region 40 by welded connections or screw connections. The shaped sheet metal parts 60, 61 are preferably designed as shaped sheet metal parts which are produced from a steel plate by cutting out, for example laser cutting or flame cutting.

In a mast 1 according to the invention with the X-shaped cross member 3 of the Figures 4 to 6 the inspection openings 45a, 45b provide an improved view through the mast 1 for an operator located on the driver's workstation of the industrial truck at different lifting heights of the mast 1 and thus of the load suspension device, since the inspection openings 45a, 45b are the fork tips of the fork tines of a load suspension device designed as load forks can see in a normal posture and with a normal viewing direction, since the fork prong tips of the fork prongs can be seen through the see-through openings 45a, 45b of the cross member 3 according to the invention.

In the Figure 5 is this on the mast 1 of the Figure 4 made clear. In the Figure 5 the mast 1 is shown with the load handling device fully lowered. The load handling device is designed as a load fork with two fork prongs, one of which is in the Figure 5 a right fork prong 30 is shown. In the Figure 5 the field of view of an operator located at the driver's workstation of the industrial truck with a normal posture and with a normal viewing direction at the fork prong 30 is shown. In this lifting position of the load handling device, the fork prong tip 30a of the fork prong 30 is not covered by the cross member 3, but can be seen through the transparent opening 45b of the cross member 3 so that the operator can see the fork prong tip 30a with a normal posture and normal viewing direction.

In the cross member 3 according to the invention, the optimized height H at the outer ends of the cross member 3, the optimized height H leading to lower bending stresses in the cross member 3, which result from the forces from the attachment of the lifting means 10, the mass of the four Web 41-44 and their cross-section are reduced, so that large see-through openings 45a, 45b are achieved in the cross member 3. The cross member 3 according to the invention has a maximum field of vision and an improved view of the fork prongs 30a of the fork prongs 30 for the operator located at the driver's workstation of the industrial truck due to the shape and X-shaped shape. Due to the large see-through openings 45a, 45b of the cross member 3 according to the invention, compared to the prior art, there is a significantly improved view of the operator of the industrial truck located in the driver's workplace through the lifting mast 3 of the fork tips 30a of the fork prongs 30, one as a load fork with two Fork tines trained load handling device. The improved and optimized view of the fork prong tips 30a of the fork prongs 30 leads to an improved orientation of the operator of the industrial truck who is at the driver's workstation of the industrial truck. In addition, the cross member 3 according to the invention leads to improved ergonomics for the operator located in the driver's workstation of the industrial truck, since the operator has a view of the fork tips 30a with a normal posture and normal viewing direction, so that no change in posture and / or viewing direction is necessary to get a view of the fork tips 30a.

In the case of the cross member 3 according to the invention, the increased and optimized height H at the outer ends of the cross member 3 also results in reduced bending stresses and torsional stresses in the cross member 3 due to the forces introduced from the fastening of the lifting means 10 and the lifting cylinder device 5. When the cross member 3 is connected to the profile rails 3a, 3b by welded joints, the enlarged and optimized height H at the outer ends of the cross member 3 also results in lower stresses in the weld seams of the welded joints. This has a favorable effect on the fatigue strength of the cross member 3 according to the invention.

The invention is not limited to that in the Figures 4 and 5 illustrated embodiment with an embodiment of the one-piece cross member 3 as a forged component or as a cast steel component. Alternatively, the one-piece cross member 3 of the Figures 4 and 5 be designed as a sheet metal part and made from a steel plate by bending, for example pressing, or cutting, for example laser cutting or flame cutting.

The invention is also not limited to that in US Pat Figure 6 illustrated embodiment with a multi-part cross member 3 is limited. A multi-part cross member 3 can alternatively be formed as a welded assembly, one of the Figure 4 or the Figure 6 has a comparable shape.

Instead of the design of the lifting cylinder device 5 with a single lifting cylinder 5a and a single lifting means 10, the lifting cylinder device 5 can be formed by several lifting cylinders and several lifting means 10.

As an alternative to being designed as a lifting chain, the lifting means 10 can also be designed as a lifting belt or as a lifting rope.

The mast 1 according to the invention can be designed as a standing mast of a single-section mast (simplex mast) or as an extending mast of a multi-section mast, for example a duplex mast or a triplex mast.

Claims (16)

1. Industrial truck with a lifting frame which comprises a lifting mast (1), wherein the lifting frame is provided with a load suspension means which can be raised and lowered, and the lifting mast (1) has two profile rails (2a, 2b) which are spaced apart laterally and are connected to one another by means of at least one crossmember (3), wherein the crossmember (3) is X-shaped and consists of a central region (40), which is arranged between the profile rails (2a, 2b), and struts (41-44), which are fastened to the profile rails (2a, 2b) and extend in an X-shaped manner from the central region (40) to the profile rails (2a, 2b), wherein in each case one viewing opening (45a; 45b) is formed between the central region (40) and two struts (41, 42; 43, 44) which extend to one of the two profile rails (2a; 2b), which viewing opening (45a; 45b) extends as far as one of the two profile rails (2a; 2b), wherein a lifting carriage which is provided with the load suspension means is arranged such that it can be displaced longitudinally in the profile rails (2a, 2b), characterized in that the lifting mast (1) is provided with a lifting cylinder device (5) for raising and lowering the lifting carriage in the profile rails (2a, 2b), wherein the lifting cylinder device (5) is operatively connected to a lifting means (10) which is fastened by way of a first end to the lifting carriage and is fastened by way of a second end (10b) to the lifting mast (1) and is deflected on the lifting cylinder device (5), wherein the lifting cylinder device (5) is supported on the X-shaped crossmember (3).
2. Industrial truck according to Claim 1, characterized in that the crossmember (3) has a first strut (41) which runs in a manner which rises in the vertical direction from the central region (40) to the first profile rail (2a) and is fastened to the first profile rail (2a), has a second strut (42) which runs in a manner which falls in the vertical direction from the central region (40) to the first profile rail (2a) and is fastened to the first profile rail (2a), has a third strut (43) which runs in a manner which rises in the vertical direction from the central region (40) to the second profile rail (2b) and is fastened to the second profile rail (2b), and has a fourth strut (44) which runs in a manner which falls in the vertical direction from the central region (40) to the second profile rail (2b) and is fastened to the second profile rail (2b).
3. Industrial truck according to Claim 1 or 2, characterized in that the struts (41-44) are fastened in each case separately from one another to the profile rails (2a, 2b) by means of dedicated fastening interfaces (BF1-BF4).
4. Industrial truck according to one of Claims 1 to 3, characterized in that an upper side (50) of the struts (41-44) runs in a rising manner at least partially from that side of the lifting mast (1) which faces away from the load to that side of the lifting mast (1) which faces the load, and an underside (51) of the struts (41-44) runs in a falling manner at least partially from that side of the lifting mast (1) which faces away from the load to that side of the lifting mast (1) which faces the load.
5. Industrial truck according to one of Claims 1 to 4, characterized in that the lifting means (10) is fastened to the crossmember (3).
6. Industrial truck according to Claim 5, characterized in that the lifting cylinder device (5) is arranged between the profile rails (2a, 2b), wherein the lifting cylinder device (5) is supported on the central region (40) of the crossmember (3), and/or the lifting means (10) is fastened to the central region (40) of the crossmember (3).
7. Industrial truck according to one of Claims 1 to 6, characterized in that the crossmember (3) is configured in one piece.
8. Industrial truck according to Claim 7, characterized in that the crossmember (3) is configured as a forged component or as a cast steel component.
9. Industrial truck according to Claim 7, characterized in that the crossmember (3) is configured as a shaped sheet-metal part.
10. Industrial truck according to one of Claims 1 to 6, characterized in that the crossmember (3) is configured in multiple pieces.
11. Industrial truck according to Claim 10, characterized in that the crossmember (3) is composed of the central region (40) and the struts (41-44), wherein the struts (41-44) are fastened to the central region (40) by way of welded connections or screwed connections.
12. Industrial truck according to Claim 11, characterized in that the central region (40) is configured as a forged component or as a cast steel component.
13. Industrial truck according to Claim 11 or 12, characterized in that the first strut (41) and the second strut (42) are formed by a first shaped sheet-metal part (60), and the third strut (43) and the fourth strut (44) are formed by a second shaped sheet-metal part (61), wherein the two shaped sheet-metal parts (60, 61) are fastened to the central region (40) by way of welded connections or screwed connections.
14. Industrial truck according to one of Claims 1 to 13, characterized in that the load suspension means is configured as a load fork with two fork arms (30), wherein the viewing openings (45a, 45b) on the crossmember (3) enable a view by an operating person who is situated at a driver workstation of the industrial truck of the fork arm tips (38) of the fork arms (30) in the completely lowered position of the load suspension means.
15. Industrial truck according to one of Claims 1 to 14, characterized in that the lifting mast (1) is configured as a stationary mast of a simplex lifting frame.
16. Industrial truck according to one of Claims 1 to 14, characterized in that the lifting mast (1) is configured as an extendable mast of a multiple-piece lifting frame.

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