TECHNICAL FIELD

The present invention relates to a mobile personnel elevator.

BACKGROUND

Such an elevator may be used by personnel for resettling items, typically lighter items, from or to an elevated level in a warehouse, a grocery store, or the like. DE202018105169 U1 discloses a hand-driven personnel lift.

SUMMARY

It is an object of the invention to provide an improved mobile personnel elevator. To this end, there is provided a mobile personnel elevator, comprising a vertically fixed section, one or more flexible driving elements each arranged, at the vertically fixed section, to run in a continuous loop, a cage for carrying a person, where the cage is fixed to each of the one or more flexible driving elements, and a motor configured to drive each of the one or more flexible driving elements for raising or lowering the cage.

This may provide vertical hoisting of at least one person including additional cargo in a convenient, safe, and fast manner in relatively confined spaces.

The flexible driving element may be any elongate object capable of carrying a tension force in a longitudinal direction, and flexible in a transversal direction, such as a such as a rope, belt with or without cogs, a wire or the like. In the case of a belt with cogs, wheels pivoted at the vertically fixed section may have corresponding cogs.

The term “continuous loop” as used throughout this disclosure should be understood as including the case of the one or more flexible driving element being connected to an object which it drives at two points spaced apart.

The one or more flexible driving being arranged at the vertically fixed section should be understood as the one or more flexible driving elements being arranged directly at the vertically fixed section, for example through wheels, bearings or the like, pivoted at the vertically fixed section. The cage being fixed to each of the one or more driving elements should be understood as the cage being geometrically stationary with respect to one or more attachment points at the flexible driving elements and include the case of the cage being indirectly fixed to the one or more flexible driving elements, for example through a sled.

The one or more flexible driving elements may comprise one or more chains. This allows for rigid and secure holding of a heavy load and allows for particularly safe and precise operation the mobile personnel elevator.

The one or more chains may be manufactured from stainless steel or other essentially non-elastic and durable materials.

The one or more flexible driving elements may comprise a plurality of chains. This provides redundancy should one of the chains fail, increasing safety.

Each of the continuous loops may run between a lower wheel located towards a base of the vertically fixed section and an upper wheel located towards the top of the vertically fixed section.

Since the movement of the cage of the mobile personnel elevator thereby may take place essentially vertically, the vertical alignment of the flexible driving elements ensures a high degree of power transmission in order for the cage with cargo to be elevated vertically. In respect to this, the motor consumes a minimal amount of electric power.

The motor may be configured to drive the lower wheel. This allows the motor to be easily placed close to the base of the elevator without an additional transmission mechanism, lowering the center of gravity of the elevator, improving stability.

Each of the one or more flexible driving elements may run in a plane whose normal direction points towards the cage, or, alternatively expressed, towards a front side of the vertically fixed section. This is a particularly compact way of arranging the mobile personnel elevator.

The one or more flexible driving elements may be located inside the vertically fixed section.

By confining the one or more flexible driving elements inside the vertically fixed section, wear is reduced and thereby maintenance by lubrication means, cleaning and the like. Further, safety is increased as the flexible driving elements are inaccessible to a user. The cage of the mobile personnel elevator may be fixed to each of the one or more flexible driving elements through a sled comprising a plurality of wheels configured to roll against said vertically fixed section.

As the sled is attached to the flexible driving elements, the sled may move along the vertically fixed section whenever the motor runs. The sled rolling against the vertically fixed section minimizes the exposed torque on the flexible driving elements, in that the torque from the load of the cage is taken up by the sled and transferred to the vertically fixed section, so that essentially only vertical tension is introduced on the flexible driving elements. At the same time, the wheels reduce friction between the sled and the vertically fixed section.

The sled is may be fixed to the one or more flexible driving elements through one or more flanges that protrude from the interior of the sled.

The vertically fixed section may comprise a C-shaped profile. This allows for a particularly stiff and strong vertically fixed section further enabling the vertically fixed section to resist a high torque caused by a significant laterally separated external load of the cage.

The C-shaped profile may be a metal profile manufactured by a durable metal alloy, such as stainless steel, and has preferably a thickness of at least five millimeters.

The C-shaped profile may further have an open end that enables convenient mounting and maintenance of the components of the interior of the C- shaped profile.

Further, the sled may comprise a first U-shaped profile oriented oppositely to said C-shaped profile. This is a particularly compact way of arranging the vertically fixed section.

The wheels may be located on the outside of the prongs of the first U- shaped profile and rolling against flanges located at the ends of the prongs of the C-shaped profile. This also allows for a particularly compact vertically fixed section.

The C-shaped profile may be formed such that the wheels of the sled roll at the interior of the C-shaped profile.

The C-shaped profile may be comprised of two parts. This enables saving of building material as well as a slightly lighter and more durable mobile personnel elevator, while retaining structural strength. The vertically fixed section may further comprise a lid located between the one or more flexible driving elements and a cage-facing side of the C-shaped profile, or, alternatively expressed, towards a front side of the vertically faced section. This provides enhanced user safety as well as enhanced lateral and vertical stiffness of the vertically fixed section.

The wheels may roll on an internal surface of the vertically fixed section.

Alternatively, the wheels may roll on an outer surface of the vertically fixed section.

The vertically fixed section may be a vertical column, or comprised in a vertical column. For example, the vertical column may enclose the vertically fixed section, being directly or indirectly attached to the sled of the vertically fixed section.

The top of the vertical column may include storage means attached to the vertical column to hold smaller hand-held tools and the like.

In proximity of the top of the vertical column there may be a control unit that is electrically connected to the motor, for fast and convenient vertical raising or lowering of the cage.

The term “front side” as used herein is referred to the side of the vertically fixed section at which the cage is attached, i.e. the cage side. Occasionally the term “front side” will be interchangeably used as “cage side” in the forthcoming text. The term “rear side” is conversely referred to as the opposite side of the vertically fixed section.

The cage may comprise a standing platform that may include vertical safety railings at a front side, and horizontal safety railings that at least partly extend along the sides of the cage of the mobile personnel elevator.

The front side of the cage may further comprise pivotable safety railings which may be attached to the horizontal railings by hinges or the like.

A floor of the standing platform may comprise an uneven surface ensuring increased friction between a user and the uneven surface, thereby enhancing user safety.

An underside of a base of the mobile personnel elevator may comprise four wheels attached to laterally protruding portions of the base. The front-side wheels are preferably horizontally pivotable for convenient horizontal steering of the mobile personnel elevator. The rear-side wheels are preferably fixed in that the rotational axes of the back wheels are perpendicular to the direction of motion of the mobile personnel elevator whenever it is laterally moved forward or backwards.

A plurality of the wheels may comprise locking means in that the mobile personnel elevator may be locked in lateral direction, which enhances user safety when in use.

The motor may comprise a worm gear that provides silent operation, a compact design, as well as high efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, some non-limiting embodiments, and further advantages of the invention will now be described with reference to the drawings in which:

Fig. 1 illustrates a mobile personnel elevator,

Fig. 2 is a perspective view of a fixed vertical section of a first embodiment,

Fig. 3 is a perspective view of a fixed vertical section of a third embodiment,

Fig. 4 is an enlarged view of the surroundings close to a base of a fixed vertical section of a first embodiment,

Fig. 5 shows an enlarged view of a vertically movable sled according to a second embodiment,

Fig. 6 shows a front view of a vertically fixed section of a second embodiment, demonstrating a vertically movable sled, flexible driving elements and a lower and an upper wheel, and Figs 7, 8, and 9 show a cross section profile of an interior of a vertical fixed column according to, respectively, the first, the second and the third embodiment.

DETAILED DESCRIPTION

Fig. 1 shows a mobile personnel elevator 10.

The mobile personnel elevator 10 comprises a cage 90 that may be raised and lowered during operation of the mobile personnel elevator 10.

The cage 90 may comprise, as shown, a standing platform 11 , vertical safety railings 12 at a front side, and horizontal safety railings 13 that at least partly extend along the sides of the cage of the mobile personnel elevator. The front side of the cage may further comprise pivotable safety railings 14 which may be attached to the horizontal railings by hinges or the like. The safety railings 14 may be lockable when the mobile personnel elevator 10 is in use.

The mobile personnel elevator 10 further comprises a vertical column 20.

The vertical column comprises a vertically fixed section (of. Fig. 2).

In proximity of the top of the vertical column there may be storage means in the form of a shelf 15 attached to the vertical column 20 to hold smaller hand-held tools and the like.

In proximity of the top of the vertical column, the mobile personnel elevator 10 may comprise a control unit 16 electrically connected to a motor (see below), for convenient and fast vertical raising or lowering of the cage.

Parts of the vertical column 20 may move vertically. The cage 90, the shelf 15 and the control unit 16 may be stationary with respect to the movable parts of the vertical column 20.

An underside of a base 17 of said mobile personnel elevator may preferably comprise four wheels, comprising two front-side wheels 117a and two rear-side wheels 117b, with each of the wheels 117a, 117b attached to a respective protruding portion 19 of the base.

The front-side wheels 117a may preferably be pivotable around a respective vertical axis.

The rear-side wheels 117b may preferably each have a respective fixed rotational axis perpendicular to the direction of motion of the mobile personnel elevator whenever it is moved forward or backwards.

Each rear-side wheel may preferably comprise locking means blocking rotation of the respective wheel. Whenever the mobile personnel elevator is laterally anchored by the locking means, the vertical column, the cage, the control unit and the storage means may move essentially vertically.

Typical, non-limiting, dimensions of the mobile personnel elevator 10 may be as follows. A nearest lateral distance between an imaginary wheel axis spanned by a front pair of wheels 117a and a rear pair of wheels 117b, may be between 70 and 90 cm. A lateral dimension between a left wheel and a right wheel may be between 50 and 70 cm. A vertical height, i.e. a vertical distance between the plane spanned by the wheels 117a, 117b and the top of the storage means 15, with the mobile personnel elevator in its most compact state, may be between 140 and 160 cm. The relatively compact lateral size allows for a small turning radius, which further allows operation of the mobile personnel elevator in limited spaces.

Fig. 2 is a perspective view of a vertically fixed section 120 comprised in the vertical column 20 a mobile personnel elevator 10 (of. Fig. 1) according to a first embodiment or a second embodiment. The vertically fixed section 120 has a housing in the form of a first C-shaped profile 22 (of. Figs 4-6 and see below).

Further, still with reference to Fig. 2, the vertically fixed section may comprise a motor 25 located in proximity to a base 17 of the vertically fixed section 120.

The motor 25 may comprise a worm gear (not shown).

The motor may, as shown, be encased by a U-shaped motor enclosure 26 which has a vertical extent that is preferably, as shown, may be significantly smaller than that of the first C-shaped profile 22.

Further, the open portions of the first C-shaped profile 22 and the U-shaped motor enclosure 26 may point in opposite directions. The first C-shaped profile and the U-shaped motor enclosure may be attached to each other by fastening means, such as screws of dimensions M6x10. The fastening means may be manufactured by a durable metal alloy such stainless steel or the like. The screws may be fitted in pre-drilled threads in the goods or nut plates. Pre-drilled holes and nuts are for instance also possible.

The first C-shaped profile 22 and the U-shaped motor enclosure 26 are further attached by a first 24a and a second 24b angle iron, each mounted laterally external to the first C-shaped profile 22 and the U-shaped motor enclosure 26 and each comprised of a base and two flanges, each of the two flanges being perpendicular to the base.

With reference to Fig. 4, the motor 25 comprises a driving shaft 34 having a rotational axis that is directed perpendicular to a base 22a (of. Fig. 7) of the first C- shaped profile 22, and extending through the base 22a into the interior 22b (of.

Fig. 7) of the first C-shaped profile 22, via aligned preferably circular holes in the first C-shaped profile 22 and the U-shaped motor enclosure 26. The driving shaft may extend at least two centimeters, preferably at least three centimeters, and most preferably at least four centimeters into the interior 22b of the first C-shaped profile 22. The driving shaft 34 may comprise a first set of sprocket wheels 32 or the like, preferably comprising a rear, an intermediate, and a front sprocket wheel. A different number of sprocket wheels is also possible. The first set of sprocket wheels 32 may be fitted on the driving shaft such that all cogs of each one of the first set of sprocket wheels essentially traverse the same path upon axial rotation of the driving shaft, i.e. the plane of a mounted sprocket wheel is perpendicular to the rotational axis of the driving shaft.

With reference to Fig. 6, at a top of the first C-shaped profile 22 a first top plate 28 that is attached by fastening means to the first C-shaped profile 22. An upper shaft 35 is attached beneath the first top plate 28, i.e. inside the first C- shaped profile 22, wherein the direction of the rotational axis of the upper shaft 35 essentially corresponds to the direction of the rotational axis of the driving shaft 34.

Between the first top plate 28 and the upper shaft, a third angle iron 27 is attached by fastening means to the first top plate 28 and the first C-shaped profile 22. The first top plate 22 preferably has similar dimensions as the outer edge of the first C-shaped profile 22.

The upper shaft 35 comprises a second set of sprocket wheels 36, which may comprise a rear sprocket wheel and a front sprocket wheel. The rear sprocket wheel and the front sprocket wheel of the second set of sprocket wheels 36 may be located right above, respectively, the rear and front sprocket wheel of the first set of sprocket wheels 32.

A first chain 30a (cf. Fig. 4) runs over the rear sprocket wheel of the first set of sprocket wheels 32 and over the rear sprocket wheel of the second set of sprocket wheels 36.

A second chain 30b (cf. Fig. 4) runs over the front sprocket wheel of the first set of sprocket wheels 32 and the front sprocket wheel of second set of sprocket wheels 36.

The first chain 30a and the second chain 30b thus function as flexible driving elements arranged at the vertically fixed section 120 and running in a continuous loop inside the vertically fixed section 120.

Alternatively (not shown), there may be only one flexible driving element 30 in the form of one chain, running between a lower sprocket wheel and an upper sprocket wheel. The first 30a and the second 30b chain may, as shown, run in a plane whose normal direction points towards (or in the opposite direction of) the cage 90.

Whenever the motor 25 runs, the driving shaft 34, and thereby the first set of sprocket wheels 32, rotate, which in turn drives the continuous loop of flexible driving elements 30, i.e. , the first chain 30a and the second chain 30b, over the second set of sprocket wheels 36.

Still with reference to Fig. 6, the upper shaft 35 is attached to, but vertically separated from, the first top plate 28. The vertical separation between the upper wheel shaft 35 and the first top plate may be achieved by two vertically aligned rods (not shown) that have pre-drilled threads at the top and external threads at the bottom. The vertically aligned rods may be attached to the first top plate 28 by appropriate screws that fit the pre-drilled threads. The external threads at the bottom of respective vertically aligned rod may be comprised by nuts that allow adjustment of the tension of the flexible driving elements 30. The second set of sprocket wheels 36 may rotate about the upper wheel shaft by intermediate ball bearings (not shown), while the upper shaft 35 may be fixed.

Fig. 5 shows a perspective view of a sled 40 comprising a first U-shaped profile comprising a base and two prongs, where the first U-shaped profile is oriented oppositely to the first C-shaped profile (cf. Fig. 7). The sled 40 is attached to the first and the second chain 30a, 30b by at least one flange 44 that is attached by fastening means at the interior of one of the flanges of the first U-shaped profile. The sled 40 further preferably comprises four wheels 42 that are externally located in proximity of the corners of the prongs of the first U-shaped profile. The four wheels 42 may then roll at the interior of the first C-shaped profile 22 (cf. Fig. 7), at flanges 22c the ends of the prongs of the first C-shaped profile 22 and thus against an internal surface of the vertically fixed section 120, in that the sled 40 may move vertically while the motor 25 runs, which assures reduced friction and minimal lateral play. The sled 40 further preferably comprises a plurality of adjustable feet 46 in proximity of the wheels 42, where respective screw head is externally located on the sled 40. The adjustable feet 46 further minimize lateral displacement of the sled 40.

The lateral sideway separation between the protruding one or more flanges of the sled, and the side at which the flexible driving elements which the one or more flanges are attached to, may be relatively small in order to reduce unnecessary asymmetric load and wear of the wheels of the sled, although without compromising with the overall lateral stability of the vertically fixed section. This lateral sideway separation may be approximately 30 mm.

The vertical length of the sled is preferably may be at least 30 centimeters, and the vertical distance between the axes of the wheel pairs may be at least 20 centimeters.

The vertical separation of the wheels of the sled may further reduce the stress and the strain of the C-shaped profile.

The cage 90 (cf. Fig. 1) is mechanically fixed to the sled, either directly or indirectly. Thus, in turn, the cage 90 is fixed to the flexible driving elements 30 in the form of the chains 30a, 30b through the sled 40. Further, with the motor 25 driving the first set of sprocket wheels 36 through the shaft 34, running the motor 25 may raise or lower the cage.

The vertically fixed section may further comprise a microswitch assembly (not shown) comprising a microswitch. The microswitch assembly is internally attached to the first C-shaped profile, wherein the microswitch is mounted such that it turns off an electrical current that drives the motor, as soon as the sled 40 reaches a specific vertical distance, e.g. in proximity of the top of the first C- shaped profile.

Fig. 7 shows a lateral cross section of the first C-shaped profile 22, the sled 40 and a U-shaped lid 80 comprised in the vertically fixed section.

The fit of the wheels 42 inside the C-shaped profile is preferably such that there is less than two millimeters of space between the wheel and the portion of the C-shaped profile that the wheels do not roll against, i.e. the opposite side of the contact point between the wheels and the C-shaped profile.

A base of the U-shaped lid may extend along the ends of the first C-shaped profile such that the open ends of the U-shaped lid 80 and the first C-shaped profile are directed in opposite directions. The U-shaped lid 80 extends preferably at least partly over the full vertical length, and more preferably over the full vertical length of the first C-shaped profile 22.

Thus, the lid has a lateral U-shaped cross section and is assembled with the vertically fixed section in that the open portions of the profile of respective embodiment and the lid are pointing in opposite direction towards each other. The mounted U-shaped lid leaves two vertically oriented tracks 52 between the prongs of the first C-shaped profile and the lid such that the base of the sled 40 may run vertically outside the lid in that the prongs of the sled 40 is not necessarily in direct contact with either the first C-shaped profile 22 nor the lid.

The lateral space of respective vertically oriented track 52 is preferably, but not limited to, at least 10 m.

Fig. 8 illustrates the second embodiment of the vertically fixed section 120 comprising a housing in the form of a second C-shaped profile 62a, 62b. The second C-shaped profile comprises a left 62b and a right part 62a wherein the left and right parts both are respective U-shaped profiles, mounted such that their openings point in opposite directions towards each other. These left 62b and right 62a parts are attached to each other by a frontal plate 64, so that the frontal plate 64 abuts a frontal prong of respective left and right part to form the second C- shaped profile. As the frontal plate 64 is structurally significantly less exposed of the torque of the load of the cage, it may be made from relatively thin plate, such as at least 1 mm thick metal plate, whereas the left part 62b and right part 61 may have a thickness of preferably at least five millimeters. Towards the base of the second C-shaped profile, the C-shaped profile may comprise further portions 66a, 66b, 67a, and 67b for further stability Remaining external and internal parts of the second embodiment are essentially similar to the external and internal parts of the first embodiment.

Thus, in the third embodiment, the C-shaped profile into two pieces, where the flanges of the C-shaped profile consist of two smaller oppositely oriented U- shaped profiles having their respective open portion directed towards each other. These two smaller oppositely oriented U-shaped profiles may by connected through a plate which may be an essentially rectangular plate. The third plate may be assembled to the two smaller U-shaped profiles by fastening means to respective flange of these U-shaped profiles.

The smaller thickness of the plate enables saving of building material as well as a slightly lighter and more durable mobile personnel elevator, while retaining the structural advantages of the first preferred embodiment.

Fig. 3 shows a perspective view of the third embodiment of a vertically fixed section (170). In the third embodiment the vertically fixed section comprises a housing 70 that has a lateral cross section (of. Fig. 9) that deviates from a U- shaped profile in that each of its the prongs are bent to form additional flanges 78a and 78b that protrudes from respective prong. The respective flange 78a and 78b preferably has a U-shaped profile, and the open portions of these flanges essentially point towards each other. The third housing 70 comprises an externally mounted second sled 72. The second sled 72 has a lateral cross section that has a U-shaped profile and preferably comprises four wheels 74 on respective prong, the four wheels mounted on respective corner of an interior of the respective prong of the second sled 72. The wheels 74 preferably roll on the exterior of the flanges 78a and 78b of the third housing 70 of the vertically fixed section 170, i.e. , on an outer surface of the vertically fixed section 170. The described second sled 72 of the third embodiment thus preferably comprises eight wheels that encloses the housing in that there are two space separated wheels in each space dimension. The third housing 70 further comprises a second top plate 73 located at the top of the third housing, functionally similar to the first and second top plate. The second top plate 73 preferably has similar dimensions as the outer edge of the third housing 70.

Thus, the general structure of the vertically fixed section of the third embodiment is a deformed U-shaped profile, where its respective prong is formed as an additional U-shaped protrusion located essentially at the center of the prong.

The additional U-shaped protrusions are located such that respective open portion points towards each other. This embodiment may use a different vertically movable sled (of. Fig. 3) that embraces the vertically fixed section, that has preferably at least eight wheels that roll vertically against the additional U-shaped protrusions, i.e. the sled has at least two wheels in each space dimension to ensure lateral and vertical stability and stiffness. The third embodiment further allows for a reduced diameter of respective wheel, which further allows respective wheel being located closer to the interior corners of respective prong of a second U-shaped sled, so that the lever arm of the counterweight is increased, which reduces the mechanical pressure, and thereby the wear, of the contacting surface between the wheels and the vertically fixed section.

The embodiments described above and as shown in the figures may be varied in many ways without departing from scope of the claims.