TECHNCAL FIELD

The present invention refers to a stairlift device for carrying out at least one motion or actuation for arranging a chair or seat of the stairlift device for a de-/boarding process, the stairlift device exhibiting: a drive unit comprising a first drive configured for driving and positioning the stairlift device along a rail and comprising at least one further drive configured for actuating/rotating the chair or seat around at least two spatial directions/axes. Furthermore, the present invention refers to methods for controlling de-/boarding kinematics of such stairlift devices. In particular, the present invention refers to devices and methods according to the respective present independent claim.

BACKGROUND

Stairlifts for individuals are commonly used e.g. in private houses, especially also in context with passenger transportation of physically hampered persons. Stairlifts are commonly used by elderly people getting more and more difficulties in walking stairs. One of more specific difficulties faced by some individuals is a limitation in knee flexion; in particular, for some individuals, getting seated and/or standing up from a seated position becomes more and more difficult especially for elderly individuals. In that context, stairlifts according to prior art may exhibit a seat being adjustable in height, and/or the stairlift’s armrests can be engineered/designed for leaning on (absorbing/transmitting the user’s weight) while getting seated or rising from the seat.

EP 1 197 465 Bl describes a seat capable of being pivoted up and downward on a substantially horizontal pivot axis. Also, the following publications describe means and methods for facilitating comfortable use of stairlift devices: US 2021/163263 Al, US 2017/001837 Al, US 5 533 594 A.

Previously known mechanisms do not yet allow for a very user-friendly de-/boarding process with the chair being arranged in optimized ergonomic position. SUMMARY

It is an object of the present invention to provide for means and methods for enhanced de- /boarding possibilities in context with stairlift devices, especially in view of high user comfort and high security. In particular, a/the object of the present invention is to provide for a concept allowing for implementing a favourable de-/boarding process for a broad spectrum of stairlifts.

The object of the invention is solved by the features of the independent main claims. Advantageous features are indicated in the subclaims. The features of the subclaims can be combined with the features of the main claims and further subclaims.

In particular, the object is therefore solved by a stairlift device configured for carrying out at least one motion or actuation for arranging a chair or seat of the stairlift device for a de- /boarding process, the stairlift device exhibiting: a drive unit exhibiting a first drive configured for driving and positioning the stairlift device along a rail (in order to overcome a/the stair) and exhibiting at least one further drive configured for actuating/rotating the chair or seat around at least two spatial directions/axes; wherein the drive unit is configured for swivelling the chair or seat around a swivel axis and for tilting the chair or seat around a tilting axis in such a manner that in a landing area the seating area/plane of the chair or seat can be arranged in inclined manner for a (de-)boarding user, especially with the seating area/plane inclined by at least 10° or 15° or 20° with respect to a horizontal plane. These swivelling and tilting kinematics provide for a favourable de-/boarding process with increased comfort and security, especially based on predefined angles of rotation and optionally also based on at least one (pre-)condition, e.g. based on momentary sensor data. A user may sit down in the chair in quite comfortable manner, especially depending on his/her physical abilities. Also, getting up (getting out of the chair) is sensibly facilitated for users.

In other words: The above mentioned object can be solved by using swivelling and tilting/levelling (and optionally also lifting) kinematics for arranging the chair in a boarding arrangement, e.g. by swivelling the chair by e.g. 90 degrees (in at least one swivelling direction, e.g., the stairlift device preferably is configured for swivelling in two opposite swivelling direction resp. swivel positions), especially away from the stairs (depending on momentary configuration and relative positions), and then tilting the chair resp. seat, especially by using a tilting/levelling drive. Further, a lifting process can be carried out in order to further facilitate getting out of the chair, wherein at least the armrests and optionally also the backrest can be lifted. Optionally, detection of the swivel angle (especially 90°) can be defined as a pre-condition for defining a starting point for tilting the chair. Optionally, the tilting process (or tilting feature per se) can be activated by a user resp. by a user control.

Preferably, the whole chair is movably arranged according to the degrees of freedom mentioned above (two axes of rotation, optionally also translational motion for lifting of armrest).

The present invention is also based on the finding that a (small) tilted seat angle provided for increased comfort during the ride makes it harder to get out of the chair.

In the following, procedural aspects of the present invention are referred to in more detail, especially by referring to nine different stages/conditions: A user calls the stairlift device, e.g. by using a remote control, and the stairlift device rides up or down to a boarding position where the user is (momentarily) located. Optionally, the stairlift device already resides within the boarding position (neutral position). For arranging the chair/seat in a first arrangement, the stairlift device, especially its chair, swivels towards the user (especially by/around an angle of 90° with respect to its neutral boarding position, especially based on first sensor data provided by a first angle rate sensor). In the following, it is ensured that the seat is unfolded and the footrest is folded, which can be done by the user and/or the stairlift device itself (by means of optional actuators or motors controlling the respective position or actuating the respective component). Then, for arranging the chair/seat in a second arrangement, the tilting/levelling drive of the stairlift tilts the chair forward (especially only in case a pre-condition of standing still at the boarding position and the new/additional condition of being swivelled to the first arrangement are met, especially based on second sensor data provided by at least one second angle rate sensor resp. by a set of sensors). The user may now get seated on the seat tilted forward; during or for that procedure, the stairlift device optionally lifts the armrests. In the following, the stairlift’s tilting/levelling drive moves the chair back to its levelled position (first arrangement). The user (and/or the stairlift device itself) may now unfold the footrest, and the user may put his/her feet on the footrest. Then, the stairlift device swivels towards a/the swivel arrangement programmed for riding along the stairs, wherein the corresponding programmed swivel angle is dependent on the staircase situation. In other words: Then, the stairlift device swivels towards the swivel position which is suitable for riding from the boarding position; the stairlift is now ready to ride to another boarding position resp. rail position, especially in case all pre-conditions for riding are met (like e.g. fastening the seatbelt or any further individual condition being definable according to individual applications). It should be noted that the chair may also swivel towards an arrangement in different swivel angle (even by 90° swivel angle), especially in case of small stairs, in order to prevent collision with the opposite wall and/or the steps of the stairs. In other words: The stairlift device optionally swivels to another swivel position, depending on the staircase situation. During the ride, according to one mode of operation, the stairlift device continuously levels the chair horizontally, in order to align the user resp. the seating area/plane within the horizontal plane, irrespective of momentary slope/gradient of the rail. When arriving at the new boarding position (target position, e.g. upper landing area), the process resp. sequence described above can be carried out in opposite succession. Also, the stairlift device may (optionally) swivel the chair to narrow staircases, in order to prevent collisions.

Preferably, as far as the boarding/unboarding behaviour is concerned, each rotating motion is carried out subsequently within individual time slots, i.e., not at the same time. During the ride, the motions described herein (especially three motions) preferably occur in parallel (e.g., while driving, the chair is being levelled and optionally swivelled at the same time)

According to the present disclosure, when referring to “boarding”, it can also be referred to a deboarding process likewise, and vice versa. According to the present disclosure, when referring to “de-/boarding”, it is referred to at least one of a boarding or deboarding process. A respective sequence of process steps can be inverted. When referring to “(de-)boarding user”, it is referred to a personal/human action of a user; according to the present disclosure, this user action is differentiated from any de-/boarding process of the stairlift by referring to the different spelling “(de-)”. According to the present disclosure, when referring to “drive”, it is referred to a motor or actuator configured for carrying out at least one motion of the stairlift device or of the stairlift’s chair or seat.

According to the present disclosure, when referring to “chair or seat”, depending on individual configurations of respective stairlift devices, it is likewise (analogously) referred to either the seat itself (structural component) or to the complete chair; depending on individual configurations of respective stairlift devices, the skilled person may decide if the complete chair should be moved in order to tilt/incline the seating plane (which in several configurations could be preferred, in order to at least partially use already installed motors/actuators), or if only the seat should be moved.

According to the present disclosure, when referring to a boarding “position”, said boarding position designates the absolute position of the stairlift device resp. the position of the stairlift device with respect to the rail.

According to the present disclosure, when referring to a boarding “arrangement”, said (spatial) boarding arrangement designates the (relative) position and orientation of the seat of the stairlift device while the stairlift device remains/resides in the boarding position (resp. rail position). According to preferred embodiments, the boarding arrangement may comprise at least two different relative (spatial) arrangements of the seat with respect to the ground (e.g. the chair being rotated around its vertical axis / in its neutral position). Also, the boarding arrangement may designate a specific situation of the chair being folded/unfolded.

According to the present disclosure, when referring to a “landing area”, it is likewise referred to any boarding area (not only at the lower/upper end of the stairs, but also at any intermediate plateau; thus, the tilting chair behaviour can be applied at each individual boarding position.

The stairlift device is configured for carrying out the tilting of the seat or chair depending on at least one (pre-)condition (first condition) depending on a folded/unfolded state of the seat of the stairlift device and/or depending on a folded/unfolded state of an armrest of the stairlift device and/or depending on the stairlift device residing in a/the boarding position. In other words: The stairlift device is configured for carrying out the tilting of the seat or chair depending on at least one (pre-)condition (first condition) out of the following group: a folded/unfolded state of the seat, a folded/unfolded state of an armrest of the stairlift device, the stairlift device residing (resp. being located) in a/the boarding position.

According to one embodiment the drive unit is configured for at least two steps or motions for rotational actuation of the chair or seat for arranging the seating area/plane in said inclined de- /boarding arrangement, thereby providing for de-/boarding kinematics which can be implemented irrespective of any user being arranged on the seat. This kinematic concept also facilitates implementation of the inventive process in already installed (resp. built-in) stairlifts.

According to one embodiment the drive unit provides for de-/boarding kinematics for arranging the seating area/plane in said inclined de-/boarding arrangement based on a/the swivelling drive or actuator of the stairlift device and a/the tilting drive or actuator of the stairlift device. This kind of implementation also facilitates realization of the inventive concept in a plurality of different kinds of stairlifts, especially without the need of provision of any supplemental drive or actuator.

According to one embodiment the stairlift device exhibits a control unit configured to coordinate the actuation/rotation of the chair or seat around the at least two spatial directions/axes, especially depending on at least one (pre-)condition relating to a relative position or arrangement of the chair or relating to a state of motion. The control unit can also facilitate individualization of movement patterns, if desired.

According to one embodiment a/the control unit of the stairlift device is configured to evaluate sensor data provided by a sensing unit of the stairlift device, especially first sensor data provided by a first angle rate sensor (especially referring to the swivel axis) and second sensor data provided by a second angle rate sensor (especially referring to the tilting axis) and third sensor data provided by a third sensor (especially referring to the absolute position of the stairlift device and/or a momentary condition of motion/movement of the stairlift device or of at least one component of the chair). This kind of evaluation also provides for a robust and secure process. According to one embodiment the drive unit exhibits a further drive configured for lifting at least a/the armrest(s) of the stairlift device and optionally also a/the backrest, especially by an individual translational motion. The optional motion of these components may also further increase comfort and security.

According to one embodiment, for positioning in the de-/boarding position, the chair or seat is movably arranged according to at least the following degrees of freedom: two axes of rotation, namely swivel axis and tilting axis, and optionally also a translational motion for lifting at least a/the armrest(s) of the stairlift device.

According to one embodiment the drive unit exhibits at least three or four drives: the first drive for driving and positioning the stairlift device along a/the rail, a swivelling drive, a tilting drive (resp. levelling drive), and optionally also a lifting drive. This kind of differentiation with regard to drive types and movement axes not least also enables comparatively flexible process control.

According to one embodiment the stairlift device exhibits a sensing unit coupled to a/the control unit of the stairlift device, wherein the sensing unit preferably comprises at least three sensors: a first angle rate sensor referring to the swivel axis (i.e. referring to relative swivelling motion of the chair/seat), a second angle rate sensor referring to the tilting axis (i.e. referring to relative tilting motion of the chair/seat), and at least one third sensor configured for detecting the absolute position of the stairlift device (especially also with respect to a relative position along a/the rail) and/or a momentary condition of motion/movement of the stairlift device or of at least one component of the chair. This type of sensory equipment also enables a very well-founded analysis of a momentary state and a corresponding consideration in the control/regulation of the kinematics. The skilled person may individually decide, in/for each individual application, which kind of sensory equipment be appropriate.

In particular, in case the stairlift device be equipped with appropriate drives/actuators for realizing resp. carrying out de-/boarding kinematics, the above mentioned object can also be solved by a stairlift control unit configured for controlling de-/boarding kinematics of a stairlift device, especially in a stairlift device as described above, wherein the stairlift control unit is configured for evaluating at least three different kinds of sensor data, namely first sensor data provided by a first angle rate sensor referring to a swivel axis, second sensor data provided by a second angle rate sensor referring to a tilting axis, and third sensor data provided by at least one third sensor and referring to the absolute position of the stairlift device (or its relative position along a/the rail) and/or to a momentary condition of motion/movement of the stairlift device or of at least one component of the chair. This kind of implementation also allows for minimum effort as to any modifications of the stairlift. Thus, the present invention also provides for a concept of motion which can be implemented by referring to the manner of controlling the drive unit(s) of the stairlift device.

In particular, the above mentioned object is therefore also solved by a method for controlling de-/boarding kinematics of a stairlift device for a de-/boarding process, the method comprising: controlling a drive unit of the stairlift device for carrying out at least one motion or actuation for arranging a chair or seat of the stairlift device in a de-/boarding arrangement, especially controlling in a first step a first drive for driving the stairlift device along a rail and positioning the stairlift device in a boarding position in a landing area, the method further comprising controlling at least one further drive for actuating/rotating the chair or seat around at least two spatial directions/axes, namely for a first rotation for swivelling the chair or seat around a swivel axis and for a second rotation for tilting the chair or seat around a tilting axis in such a manner that the seating area/plane of the chair or seat is arranged in inclined manner for a (de-)boarding user, especially with the seating area/plane inclined by at least 10° or 15° or 20° with respect to a horizontal plane, wherein the second rotation is carried out depending on at least one (pre-)condition depending on a folded/unfolded state of the seat and/or an armrest of the stairlift device and/or depending on the stairlift device residing in a/the boarding position (which may imply at least one further drive being actuated for positioning the stairlift device in a boarding position). This method also provides for above mentioned advantages. Such a method can be carried out, e.g., in/with a stairlift device as described above. The method may also comprise controlling levelling and swivelling motions to be performed while riding along the rail, depending on the rail path (including inclination angles) and available space in the stairwell. According to one embodiment the first rotation for swivelling the chair or seat around a swivel axis is a rotary motion of about 90°, especially with respect to the neutral swivel position of the chair. According to one embodiment the second rotation for tilting the chair or seat around a tilting axis is a rotary motion of the seating area/plane of the chair or seat by at least 10° or 15° or 20° with respect to a horizontal plane. These angles of rotation also provide for favourable access.

According to one embodiment the first and/or second rotation is to be activated manually or based on at least one predefined condition, especially based on a de-/activation process implemented in a/the control unit being in communication with a user control. This also facilitates user interaction, e.g. in context with unfolding of the seat and/or folding of the footrest.

According to one embodiment the first and/or second rotation is carried out depending on at least one (pre-)condition depending on a state of motion/movement of the chair (second condition) and/or a predefined swivel and/or tilting position (third condition) and/or a seat contact activation (fourth condition) and/or a safety belt activation (fifth condition), especially according to respective sensor data provided to a/the control unit of the stairlift device. This kind of control or processing based on preconditions also facilitates implementation of a secure and user-friendly process (and potentially also user-interactive process).

According to one embodiment the method is a computer-implemented method providing program instructions to a/the control unit of the stairlift device.

In particular, the above mentioned object is therefore also solved by a computer program comprising instructions which, when the program is executed by a computer, cause the computer to execute the steps of the method as described above. For example, such computer program can be implemented to provide for control via a (remote) user control. In other words: The present invention can also be provided for already installed (resp. built-in) stairlift systems exhibiting at least the swivelling and tilting drives/actuators, by implementing corresponding control functions. In particular, the above mentioned object is therefore also solved by use of a drive unit of a stairlift device for carrying out, especially controlling, at least two motions or actuations for arranging a chair or seat of the stairlift device for a de-/boarding process in a landing area, wherein at least one drive of the stairlift device is controlled for rotating the chair or seat around a swivel axis and for tilting the chair or seat around a tilting axis, especially sequently, such that a/the seating area of the chair or seat is arranged in inclined manner for a (de- jboarding user accessing the stairlift device, especially with an tilting angle (angle of inclination) of at least 10° or 15° or 20° with respect to a horizontal plane, especially use of at least three or four drives, especially a first drive for driving and positioning the stairlift device along a/the rail and a swivelling drive and a tilting drive and optionally also a lifting drive, of a/the stairlift device as described above for carrying out the at least two motions for arranging the chair or seat in said de-/boarding arrangement. This kind of implementation also provides for above mentioned advantages especially in context with already installed (resp. built-in) stairlifts. In particular, control of the drive unit resp. of the drives can be carried out by means of a/the control unit as described above.

SHORT DESCRIPTION OF FIGURES

These and other aspects of the present invention will also be apparent from and elucidated with reference to the embodiments described hereinafter. Individual features disclosed in the embodiments can constitute alone or in combination an aspect of the present invention. Features of the different embodiments can be carried over from one embodiment to another embodiment. The drawings show, respectively in schematic illustration:

Figures 1 (Fig. 1 A to Fig. 1 J) respectively in a side view a stairlift device according to one embodiment and use of de-/boarding kinematics for positioning the chair/ seat in a favourable de-/boarding arrangement;

Figure 2 steps of a method including de-/boarding kinematics according to embodiments;

Figure 3 in a side view a stairlift device arrangement according to embodiments;

DETAILED DESCRIPTION OF FIGURES First, the reference signs are described in general terms; individual reference is made in connection with respective figures.

The present invention provides for a stairlift device 10 having a drive unit 11 exhibiting (not only) a first (main) drive 11.1 and (also) a swivelling drive or actuator 11.2 (further drive, especially second drive) and (as customary) a tilting/levelling drive or actuator 11.3 (further drive, especially third drive) and optionally also a lifting drive or actuator 11.4 (further drive, especially fourth drive). Usually, the stairlift device 10 exhibits at least the following structural components: footrest 15, chair 17 resp. seat, seating area/plane 17.1, seat back 17.3, armrests 17.5.

Usually, the stairlift device 10 travel s/drives along a rail 3 between a lower level (e.g. floor) la and an upper level lb. A user 5 may get on/off the chair in a respective landing area 7, therein the stairlift is arranged in a (neutral) boarding position PB.

According to the present invention, the stairlift device 10 provides for enhanced de-/boarding kinematics 20 based on additional actuation of the chair configured for arranging the chair/seat in a final de-/boarding arrangement PB17. A control unit 19 is in communication with the drive unit 11, thereby ensuring appropriate processing of de-/boarding kinematics 20. Optionally, a user 5 may manipulate resp. individualize the manner of control by means of a user control 19.1 (e.g. remote control). E.g., the user 5 may call a/the stairlift device 10 being arranged in an intermediate position Pi (in height) between two levels or floors by means of the remote control.

The stairlift device 10 further exhibits a sensing unit 13 comprising a first angle rate sensor 13.1 (referring to a swivel angle) and a second angle rate sensor 13.2 (referring to tilting angle) and at least one third sensor 13.3 (especially referring to at least one absolute and/or relative position or motion of at least one component of the stairlift device 10; the position of the at least one third sensor 13.3 can be chosen individually according to individual requirements in each individual stairlift system). Thus, controlling said enhanced de-/boarding kinematics 20 can also be carried out based on (momentary) sensor data. In the following, steps of the de-/boarding kinematics 20 according to the present invention allowing for arranging the chair/ seat at least in a first arrangement Pl (especially swivel position, preferably 90° swivel position) and in a second arrangement P2 (especially tilted position), are described in more detail:

In a step SO, moving/calling the stairlift device to the de-/boarding position can be carried out. As a first step SI of actuation, the chair can be swivelled to the first arrangement Pl. As a second step S2 of actuation, the chair can be tilted to the second arrangement P2, thereby arranging the chair/seat in a favourable de-/boarding arrangement. Optionally, lifting of the chair/seat or of at least the chair’s armrests (step S5) can be carried out while being/remaining arranged in the second arrangement P2. Once the user 5 has come on board, the chair can tilt (back) to the first arrangement Pl (step S3) and can swivel (step S4) to the neutral boarding position PB. In other words: the chair swivels to a swivel position which is suitable for driving from the boarding position. Achieving the neutral boarding position PB can be defined as initial starting point for initiating the driving motion (step S4a). During the process, a step S6 of checking at least one pre-condition can be carried out (especially continuously).

According to the present disclosure, the individual steps and arrangements/positions of the de- /boarding kinematics 20 are mainly described as being sequential (one after another).

Nonetheless, the skilled person understands that the individual steps and arrangements/positions may also be realized simultaneously, at least partly. The skilled person may decide for each appliance how to individually optimize the sequence.

In the figures, (a) designates a tilting angle (inclination), and (x) designates the travel direction resp. the path of motion of the stairlift device (along the rail), and (y) designates the cross direction, and (xy) designates a horizontal plane, and (z) designates the vertical direction or direction orthogonal to travel direction and cross direction, and (Yl) designates a/the tilting axis and (Zl) designates a/the swivel axis.

In Figures 1 steps of a method/process implying de-/boarding kinematics 20 are shown in detail. In particular, Fig. 1A shows the stairlift device in a (neutral) boarding position PB; Fig. IB shows the chair being swivelled for about 90° (first arrangement Pl); Fig. 1C shows the stairlift’s seat and pedestal and armrests being unfolded (which can be done manually or via actuation); Fig. ID shows the chair being tilted by about 20° or 25° (second arrangement P2 which may correspond to final de-/boarding arrangement PB17, e.g. if no lifting of the armrests or no other actuation is desired); Fig. IE shows a user in a boarding situation; Fig. IF shows the user being seated; Fig. 1G shows the chair having tilted back to the first arrangement Pl; Fig. 1H shows the footrest 15 in an unfolded situation; Fig. 1J shows the chair having swivelled back to the (neutral) boarding position PB.

In Figures 1, step SI (swivelling to de-/boarding arrangement) is illustrated by figures 1A and IB, and step S2 (tilting to boarding arrangement) is illustrated by figures 1C and ID, and step S3 (tilting back to driving position) is illustrated by figures IF and 1G, and step S4 (swivelling back to neutral position) and step S4a (initiating driving motion) are illustrated by figures 1H and 1 J.

In the figures, the at least one further drive 11.2, 11.3, 11.4 is shown in respective context of the respective actuation/motion of the seat.

In Fig. 2 steps SO to S6 are illustrated, wherein SO designates a step of moving/ calling the stairlift device to the de-/boarding position PB, and SI designates a swivelling motion towards the first arrangement Pl, and S2 designates a tilting motion towards the second arrangement P2, and S3 designates a tilting motion (back) to the first arrangement Pl, and S4 designates a swivelling motion back to the neutral position, and S4a designates initiation of a/the main driving motion of the stairlift device along the rail, and S5 designates an optional lifting (or other kind of supplemental actuation) of any component of the chair/seat, and S6 designates the process of checking at least one pre-condition, e.g. a condition (or position) of at least one of the chair’s components.

Fig. 3 illustrates different positions/arrangements, especially the neutral position PB and the final de-/boarding arrangement P2, PB17 (wherein the stairlift’s positions may remain within the neutral position PB). List of reference signs la, lb level, e.g. floor

3 rail

5 user

7 landing area

10 stairlift device

11 drive unit

11.1 first drive

11.2 swivelling drive or actuator (further drive, especially second drive)

11.3 tilting/levelling drive or actuator (further drive, especially third drive)

11.4 lifting drive or actuator (further drive, especially fourth drive)

13 sensing unit

13.1 first angle rate sensor

13.2 second angle rate sensor

13.3 third sensor, especially referring to absolute and/or relative position or motion

15 footrest

17 seat / chair

17.1 seating area/plane

17.3 seat back

17.5 armrest

19 control unit

19.1 user control, e.g. remote control

20 de-/boarding kinematics

PB (neutral) boarding position of the stairlift device

PB17 final de-/boarding arrangement of the chair/seat

Pi intermediate position (in height) between two levels or floors

Pl first arrangement (especially swivel position, preferably 90° swivel position)

P2 second arrangement (especially tilted position)

50 moving/calling the stairlift device to de-/boarding position

51 swivelling to first arrangement, especially first step of actuation of chair/seat

52 tilting to second arrangement, especially second step of actuation of chair/seat 53 tilting (back) to first arrangement, especially third step of actuation of chair/seat

54 swivelling (back) to neutral position, especially fourth step of actuation of chair/seat

S4a initiating driving motion of the stairlift device

55 lifting of chair/seat, especially at least of the chair’s armrests, especially fifth step S6 checking at least one pre-condition a tilting angle (inclination) x travel direction resp. path of motion y cross direction xy horizontal plane Y1 tilting axis z vertical direction or direction orthogonal to travel direction and cross direction

Z1 swivel axis