[0001] The invention relates to a lift assembly comprising a rail system and a lift being
capable of movement along said rail system, for example a chair lift for a disabled
person, whereby said lift can move upwards at an angle, at least along part of its
path, said rail system comprising two guides, one being provided substantially above
the other, whereby the spacing between said guides depends on the angle of inclination
of said guides and whereby supporting elements interconnect said two guides.
[0002] This type of lift may be used to convey a disabled person, who is unable to use the
staircase, upwards or downwards along said staircase. The rail system is thereby mounted
along the staircase in such a manner that a lift can move along the staircase, said
lift being positioned above said staircase during said movement. The rail along which
the lift moves may for example be secured to a wall along the staircase, but it may
also be mounted on supports which are secured to the steps on one side of the staircase.
The lift may be in the form of a chair, in which a person may be seated, or consist
of a platform onto which a wheelchair can be moved. Also other lift forms are possible.
[0003] In case of a straight staircase the rail system may consist of a straight assembly
of sections, which is mounted at the same angle as the staircase. The lift is connected
to the rail system in that it engages the upper and lower guides of the rail system
via guide units mounted on the lift, whereby the lift takes up a substantially straight
position at all times, that is, at an angle with respect to the rail system. The rail
system may furthermore be provided with a rack, which is capable of cooperating with
a gear connected to the lift, so that when the gear is driven by means of an electromotor
provided in the lift, the lift is moved along the rail system.
[0004] Usually a staircase does not consist of a single straight part, by it may comprise
different angles of inclination at different places, it may comprise a horizontal
part and it may make one or more bends. In all these cases the rail system must be
provided along the staircase in such a manner that the lift will take up a straight
position at all times during its movement along the rail system. The position of the
lift with respect to the rail system is determined by the spacing between the guides.
Consequently said spacing must vary such that the lift will remain in a straight position
at all times, irrespective of the angle of inclination of the rail system. That is,
the two guides will be spaced less far apart when the staircase, and thus the rail
system, is inclined at a steeper angle.
[0005] In most cases a lift is not provided with two guide units positioned directly above
each other, because this will present problems when the rail system comprises a horizontal
part. In order to make the lift sufficiently stable at such a horizontal part two
guide units are secured to the lift, one guide unit being positioned obliquely above
the other.
[0006] When a lift assembly is to be installed along a certain staircase, said staircase
must be measured very precisely beforehand, after which the shape and the construction
of the rail system can be computed on the basis of said measurement. Generally the
shape and the dimensions of the rail system will thereby vary along its length. In
fact the rail system is assembled and made to size as a whole at the factory, or in
parts if it should become too voluminous to transport, transported to the staircase
in question and installed along the staircase there. In practice the rail system is
always assembled at the factory by means of welded joints, partly because it is thus
ensured that all dimensions of the rail system remain unchanged at all times.
[0007] Drawbacks of known lift assemblies are the fact that they must be made precisely
to size on the basis of complicated calculations, requiring error-free measuring of
the staircase, and that reuse of the system for another lift assembly is hardly possible,
if at all, in the event that a rail system has to be removed from a house.
[0008] The object of the invention is to provide a lift assembly enabling reuse of the rail
system, at least to a large extent. Particularly because of the fact that in some
cases a lift assembly will be present in a house for a short time only, after which
it must be removed again, the possibility of reusing a considerable part of such a
lift assembly offers major advantages.
[0009] According to one aspect of the invention the rail system of the lift assembly is
provided with two guides, which are each detachably connected to the supporting elements
of said guides. Said guides preferably consist of a number of tube sections, for example
having a round cross-section, which are detachably interconnected. Such a detachable
interconnection may be effected by interposing a coupling element, which is slid into
one end of each tube section, after which a fixation may take place in that screws
are passed through the tube sections into the coupling element. The coupling elements
may also be secured in the tube sections by means of a clamped fit.
[0010] The tube sections may consist of straight tube sections and bent tube sections, which
are detachably interconnected by said coupling elements and which are likewise detachably
connected to the supporting elements. Because straight and bent tube sections are
utilized, each tube section may be used to form another rail system after the rail
system has been dismantled, possibly in combination with tube sections from other
rail systems that have been used before. Furthermore all components of the lift assembly
can be made to size in situ, using simple hand-operated tools.
[0011] According to a further aspect of the invention a supporting element for attaching
each of the two guides at a fixed location may be provided with a securing element,
by means of which the guide can be connected to the supporting element at a desired
angle, and that in such a manner that with every desired angle a predetermined spacing
between the guides is adjusted automatically. Such an automatic adjustment of the
spacing between the guides may for example be achieved in that each of the two securing
elements can rotate about a substantially horizontal axis of rotation with respect
to the supporting element, whereby the guide can be fixed to the supporting element
in a random angular position. The axes of rotation of two securing elements of a supporting
element may thereby lie in different, spaced-apart vertical planes, and at least one
of said securing elements may be designed such that its axis of rotation crosses the
central axis of the guide fastened therewith at some distance therefrom. When the
axes of rotation of the securing elements lie in different, spaced-apart vertical
planes, this means that one is not positioned directly above the other, which makes
it possible to vary the relation between the spacing between the guides and the angle
of inclination. Such a variation may also be effected in that the axis of rotation
of a securing element does not intersect the central axis of the guide fastened therewith,
but crosses it at some distance therefrom. All this will be explained in more detail
by means of an embodiment.
[0012] According to another aspect of the invention the supporting element may be provided
with two downwardly extending legs, which may each be secured to the floor and/or
a staircase, for example each leg to a different step of the staircase. Preferably
the length of each leg can be adjusted independently of the other leg.
[0013] According to another aspect of the invention a rack may be detachably secured to
the supporting elements, and that near the lower guide. The rack and/or gear meshing
therewith referred to herein may comprise teeth of any desired shape. In particular
a gear is meant comprising teeth in the shape of axial pins, which mesh with correspondingly
shaped teeth of the rack.
[0014] Preferably the location of the axes of rotation of the securing elements on the supporting
element is such that it corresponds with the location of guide units mounted on the
lift, which are likewise capable of rotating movement about a horizontal axis of rotation.
This means that when the lift occupies a certain position on the rail system, the
axes of rotation of the securing elements will coincide with the axes of rotation
of guide units, which are provided with guide wheels engaging the two guides. This
will be explained in more detail in the description of the embodiment.
[0015] Furthermore a third guide unit may be present, which engages one of the guides, for
example the upper guide. This guide assists in providing a stable support of the lift.
According to the invention said third guide unit may be secured to the lift in such
a manner that a substantially vertical movement with respect to the lift is possible.
[0016] When the two guide units are not positioned directly above each other, the lift will
not remain in a straight position when the rail system makes a lateral bend. That
is why the rail system is preferably constructed such that, seen in vertical projection,
the upper guide makes a larger (wider) curve in a bend than does the lower guide.
When the dimensions are correct the lift will maintain its straight position at all
times thereby.
[0017] The invention furthermore relates to a method for installing a rail system as defined
in the claims.
[0018] Further aspects of the invention, which may be used separately as well as in combination
with each other, will be described by means of an embodiment and are referred to in
the claims.
[0019] Hereafter an embodiment of a lift assembly according to the invention will be described
by way of illustration with reference to the schematic drawing.
Figure 1 is a perspective view of a rail system of a lift assembly, and also an exploded
view thereof;
Figure 2 is a view of a lift assembly;
Figure 3 is a view of an alternative embodiment of the lift;
Figure 4 is a partial cross-section of a rail system and a lift;
Figure 5 is a partial cross-section of a supporting element and rails; and
Figure 6 is a view, corresponding with Figure 3, of another embodiment.
[0020] The Figures are only diagrammatic view of the embodiment, wherein like parts are
numbered alike in the various Figures.
[0021] Figure 1 is a perspective and schematic view of a rail system and also an exploded
view showing the parts of said rail system. A number of supporting elements 2 are
mounted on a staircase 1. Each of said supporting elements 2 comprises two legs 3,
4, said legs at their downwardly extending ends being provided with bases 5, which
may be secured to the steps of a staircase, for example by means of screws. The legs
3, 4 may thereby be provided with an additional tube section 46 for adjusting the
length of the leg. This will be explained in more detail with reference to Figure
5.
[0022] Each supporting element 2 is secured to two successive steps, whereby a plate-shaped
intermediate piece 6 is placed under the base 5 of the shorter leg 4, said intermediate
piece 6 engaging around the longer leg 3 with one end. In this manner the attachment
of the supporting element 2 is strenghtened. A supporting element 2 is placed on the
horizontal floor 7 as well, whereby the two legs of said element have the same length.
[0023] Each supporting element 2 is provided with two securing points 8, 9, to which the
lower guide 12 and the upper guide 13 can be secured by means of securing elements
10, 11. The position of the securing points 8 and 9 is the same for all supporting
elements 2. It will be apparent that this location and also the shape of the securing
elements 10 and 11 determine the relation between the spacing between the guides 12,
13 and the angle of inclination of said guides. This spacing between the guides 12,
13 must be attuned to the construction of the lift to be moved along the rail system,
such that said lift will remain in a straight position while moving along its path.
At the bottom side of the staircase the rail system according to Figure 1 is connected
to the floor 15. At the upper side of the staircase 1 the rail system extends beyond
the floor 7.
[0024] In the exploded view of the rail system shown in Figure 1 a number of parts thereof
are illustrated in detached relationship. Each guide 12, 13 is thereby shown to be
assembled from a number of straight tube sections and a number of bent tube sections.
Said tube sections are interconnected by coupling elements 16, which may be slid into
the ends of two tube sections connecting to each other. The interconnection of the
tube sections may be strong enough per se, because the coupling elements are provided
with a clamped fit, it is also possible, however, to secure the ends of the tube sections
to the coupling elements by means of screws.
[0025] Figure 2 is a view of a lift assembly provided on a staircase 1, whereby the rail
system of said assembly corresponds with the rail system described with reference
to Figure 1. As already described before, the supporting elements 2 are secured to
successive steps of the staircase 1. Furthermore a supporting element 2 is provided
on the horizontal part 17. Also Figure 2 shows how the spacing between the guides
12, 13 changes in dependence on the inclination of said guides. This dependence is
determined by the position of the securing points 8 and 9 of the supporting elements
2 and by the shape of the securing elements, of which only securing element 10 is
shown in Figure 2.
[0026] Upper guide 13 is secured to supporting element 2 in such a manner, that the central
axis of guide 13 intersects the central axis of securing point 9. To this end the
securing element 11, which is not shown in Figure 2, is capable of rotating movement
about a horizontal axis of rotation through securing point 9, to which securing element
11 the upper guide 13 can be secured.
[0027] The lower securing element 10, which is capable of rotating movement about a horizontal
axis of rotation through securing point 8, is shown in Figure 2. The lower guide 12
is secured to said securing element 10 in such a manner, that the central axis of
said lower guide 12 crosses the horizontal axis of rotation through securing point
8 at some distance therefrom. It will be apparent that the position of securing points
8, 9 and the shape of the securing elements 10, 11 effect a certain relation between
the spacing between the two guides 12, 13 on the one hand and the angle of inclination
of said guides on the other hand.
[0028] Figure 2 shows a lift, on which a chair is placed in order to be able to move a handicapped
person along the staircase in seated position. The lift, which is shown in rear view,
is provided with a back support 18, two arm supports 19 and a seat 20.
[0029] The lift is provided with a frame 21, to which two guide units are secured, which
are capable of rotating movement about a horizontal axis with respect to frame 21.
[0030] The lower guide unit 22 is provided with a guide wheel 24, which can roll on guide
12 with a concave running surface. The lower guide unit 22 is furthermore provided
with a second guide wheel 25, which can likewise roll on guide 12. The guide wheels
24, 25 are interconnected in such a manner that they can jointly rotate about the
central axis of guide wheel 24.
[0031] The lift drive is not shown in Figure 2. Said drive may consist of a rack, which
may be secured to the securing elements 10 in front of the lower guide 12, seen in
Figure 2, and which may have upwardly directed teeth. Said teeth can mesh with a gear
positioned in front of guide wheel 24, seen in Figure 2, which is driven via a shaft,
about which the lower guide unit 22 can rotate. The drive just described is shown
in Figure 4 and will be explained in more detail with reference to said Figure.
[0032] According to Figure 2 frame 21 is provided with an upper guide unit 23 comprising
guide wheels 26 and 27, which both have a concave running surface and which can roll
on upper guide 13. Guide unit 23 is capable of rotating movement with respect to frame
21 about a substantially horizontal axis, which lies in the same plane as the axes
of guide wheels 26 and 27, said axis of rotation also intersecting the central axis
of upper guide 13.
[0033] In order to keep the lift in its straight position in a stable manner the upper guide
unit 23 is furthermore provided with two guide wheels 48, 49, which are positioned
at some distance from the guide wheels 26 and 27. As a result of this the lift engages
the rail system in three points, which results in an adequate stability.
[0034] As is apparent from Figure 2, the position of the axes of rotation of guide units
22 and 23 on frame 21 is such that when the lift is positioned at a certain location
near the supporting element, said axes of rotation coincide with securing points 8
and 9 of a supporting element. The consequence of this is that with every angle of
inclination of the guides 12, 13 the spacing between said guides is such that the
lift will remain in the same straight position at all times.
[0035] Figure 3 shows an alternative embodiment of the lift, wherein a lower guide unit
22 being identical to the one shown in Figure 2 is secured to frame 21. The upper
guide unit 23 is different from the one shown in Figure 2, however, because the guide
unit 23 of Figure 3 only comprises two guide wheels 26, 27. A third guide unit 28
is provided in order to obtain a stable connection between the lift and the rail system,
which third guide unit engages the upper guide 13. Said third guide unit 28 is capable
of rotating movement with respect to frame 21 about a horizontal axis, which intersects
the central axis of upper guide 13, but in addition to that said third guide is capable
of moving in vertical direction along frame 21, for which purpose guide unit 28 is
mounted in vertical guide means, for example consisting of a vertical bar 29, along
which the guide unit 28 can move.
[0036] The advantage of the construction according to Figure 3 is that the horizontal spacing
between guide units 23 and 28 (seen in plan view, therefore) will remain the same
at all times. This results in a stabler connection between the lift and the rail system.
[0037] Figure 4 shows a detail wherein guide units 22, 23 are illustrated in partial sectional
view, as is part of the rail system.
[0038] As part of the rail system a supporting element 2 is shown, with a lower guide unit
10 and an upper guide unit 11 secured thereto. The Figure shows in sectional view
how lower guide unit 10 is connected to a section 32 of supporting element 2 by means
of a screw 31. Securing element 10 can be fixed in various angular positions with
respect to axis of rotation 33 thereby. Axis of rotation 33 coincides with securing
point 8 according to Figure 2.
[0039] Attached to securing element 10 is lower guide rail 12, on which a guide wheel 24
and a guide wheel 25 can roll. Guide wheel 25 is capable of rotating movement in a
support 34, which support 34 is capable of rotating movement about shaft 35 of electromotor
36, which forms the lift drive. Guide wheel 24 is likewise capable of rotating movement
about shaft 35. Gear 37, in this embodiment consisting of two parallel discs, between
which pins forming the teeth are provided, is fixedly mounted on shaft 35, so that
said gear 37 can be driven by electromotor 36. Gear 37 thereby engages in a teeth
rack 38, which is connected to securing portion 39 of securing element 10 by means
of screws.
[0040] In this embodiment gear 37 is mounted directly on the shaft of electromotor 36, but
it is also possible for the gear 37 to be driven by an electromotor via a reduction
gear.
[0041] Guide 13 is connected to the upper securing element 11, and that in such a manner
that the axis of rotation 40, about which securing element 11 can rotate before being
fixed to supporting element 2, intersects the central axis of guide 13.
[0042] Guide 13 is engaged by two guide wheels 26, 27, which are both rotatably journalled
in guide unit 23, which is freely rotatable about axis of rotation 41.
[0043] Figure 4 shows the situation wherein the position of the lift on the rail system
is such that the axis of rotation 33 of securing element 10 coincides with the axis
of rotation 42 of the lower guide unit, and whereby the axis of rotation 40 of the
upper securing element 11 coincides with the axis of rotation of the upper guide unit
23.
[0044] Figure 5 is a more detailed view of the rail system in assembled condition. The lower
guide 12 is thereby fixed to securing element 10 by means of a bolt 43, because securing
element 10 is provided with a hole, through which bolt 43 may extend, and guide 12
is provided with a threaded hole, into which bolt 43 can be screwed. By securing the
guides 12, 13 to securing elements 10, 11 in this manner the tubes forming the guides
12, 13 can be reused without the threaded holes being objectionable thereby. Said
holes may thereby be covered up by threading a screw therein.
[0045] Figure 6 substantially corresponds with Figure 3, but in this embodiment the third
guide unit 52, which is capable of movement in vertical direction along guide 53,
is positioned in such manner as to engage lower guide 12. An important advantage of
this is that the path of movement of guide unit 53 in Figure 6 is shorter than the
path of movement 28 in Figure 3.
[0046] Supporting element 2 is provided with a section 32, in which the securing element
10 is fixed by means of bolt 31, and that in the desired angular position with respect
to the central axis of bolt 31. Of course said securing may take place in several
other ways in order to achieve the same effect. In a corresponding manner upper guide
13 is secured to supporting element 2. A bolt 44 is screwed into guide 13 thereby,
thus fixing guide 13 to securing element 11 as well as fixing securing element 11
to supporting element 2.
[0047] Figure 5 moreover shows the manner in which the length of leg 3, 4 can be adjusted.
To that end tube end 45 of supporting element 2 is slid into a tube section 46, which
tube section 46 is slid over an upwardly directed stub of base 5. The tube ends 45
of the supporting elements may all have a standard length thereby, whilst the height
of supporting element 2 is determined by the length of tube section 46, which can
readily be cut to the required length. The interconnection between tube end 45 and
tube section 46 may be effected in various ways, for example by passing a bolt through
both sections.
[0048] When the rail system as described above is used it becomes possible to install the
rail system in a relatively fast and simple manner, even without measuring the staircase
precisely beforehand. All tubular elements can be shortened by means of hand-operated
tools and made to size therewith. Any bends in the tubes may be formed at the factory
beforehand, but it is also possible to obtain bends by shortening a circular tube
section to a length such that the required bend is obtained.
[0049] After the supporting elements 2 have been mounted in suitable places on a staircase,
the tube sections may be cut to the required length by means of simple techniques,
which can be carried out with hand-operated tools. Then the tube sections are linked
together by means of coupling elements, which are slid into two abutting tube sections.
When the guides thus formed are then fixed in the correct position with respect to
the supporting elements, the threaded holes for securing the guides may be provided
therein by means of tools, which may be specially adapted to that end, which tools
are supported on the securing elements occupying the correct position. Thus it has
become relatively simple to provide a lift system.
[0050] Also the dismantling of the rail system can take place in a simple manner, such that
the parts can be reused after being disassembled. The used parts may thereby be sorted
and stored until certain parts can be reused. It is also possible, however, to form
another lift assembly based on an existing lift assembly, and that to size for another
staircase. By measuring both the old staircase and the new one and by making a relatively
simple computation it will then be possible to determine what parts of the old lift
assembly may remain unchanged, what parts need to be shortened or what parts need
to be added.
[0051] The embodiment described above is to be considered as such and a great many variations
are possible within the scope of the invention.
1. A lift assembly comprising a rail system and a lift being capable of movement along
said rail system, for example a chair lift for a disabled person, whereby said lift
can move upwards at an angle, at least along part of its path, said rail system comprising
with two guides, one being provided substantially above the other, whereby the spacing
between said guides depends on the angle of inclination of said guides and whereby
supporting elements interconnect said two guides, characterized in that each guide
consists of a number of tube sections having a substantial round annular cross-section,
which tube sections are detachably interconnected.
2. A lift assembly according to claim 1, characterized in that said two guides are each
detachably connected to said supporting elements.
3. A lift assembly according to any one of the preceding claims, characterized in that
tube sections are interconnected by a coupling element which is slid into both ends
of interconnected tubes sections.
4. A lift assembly according to any one of the preceding claims, characterized in that
a rack is detachably secured to the supporting elements of the lower guide, which
can mesh with a driven gear of the lift.
5. A lift assembly according to any one of the preceding claims, characterized in that
said rail system makes a bend to another substantially vertical plane, and that, seen
in vertical projection, said upper guide makes a larger (wider) curve in a bend than
does said lower guide.
6. A method for installing a rail system along a staircase, wherein a number of supporting
elements are secured to the steps and/or to the floor, after which a number of tube
sections having a substantial round annular cross-section, which may or may not be
provided with bends, are detachably interconnected and detachably secured to the supporting
elements, all this in such a manner that two guides are formed, one guide being positioned
above the other, the spacing between said guides depending on the angle of inclination
and being determined by the shape of the supporting elements.
7. A method according to claim 6, characterized in that an existing lift assembly present
on a staircase, which is to be removed, is converted into a lift system which can
be installed on another staircase, whereby it is computed on the basis of the dimensions
of both staircases by how much the tube sections of the existing lift assembly must
be shortened or lengthened and/or what new tube sections must be added.
8. A method according to claim 6 or 7, characterized in that straight tube sections are
utilized in assembling said rail system, which tube sections can be shortened to the
desired size, as well as tube sections which are bent in the shape of a part of a
circle, which tube sections can be shortened to form a desired angle.