[0001] The invention relates to a counterweight for a suspension means elevator according
to the generic term of claim 1.
[0002] The invention further relates to the correspondingly equipped elevator according
to the generic term of claim 13.
TECHNICAL BACKGROUND
[0003] Usually, elevators comprise counterweights in order to balance the cabin load. In
common suspension means elevators, the elevator motor consumes less power and needs
less torque thanks to the counterweight. Moreover, it is advantageous to suspend the
car and the counterweight in block and tackle arrangement instead of suspending it
1:1. This way the required motor torque will be reduced, which allows the use of smaller,
less expensive motors. For the purpose of realizing a block and tackle arrangement
at least one deflection pulley explicitly for the counterweight is needed.
[0004] Traditionally, all designs of such counterweights have these basic elements: At least
one rotating deflection pulley with bearings on a fixed shaft, a top protection for
parts that may fall on the pulley from above, parts that will prevent the suspension
means from coming out of the pulley groove from both sides and bottom. In addition,
the pulley must be removable for maintenance or replacement.
[0005] In traditional pulley constructions, the deflection pulley is usually protected against
falling parts by a separate sheet metal part. This means an increase in the number
of parts. Often, this also means that the overall height of the counterweight is increased.
The higher counterweight construction has negative consequences in many ways, for
example that the vertical space needed to place counterweights is reduced. To fit
a certain weight into less vertical space, higher density and more expensive materials
must be used as mass bodies for the counterweight.
[0006] While the suspension means attached to the deflection pulley of the counterweight
(or only "deflection pulley" or "pulley"), suspension means that enter from one side
of the pulley may not easily exit from the other side. This requires the installer
to carefully follow the suspension means under the pulley and guide the suspension
means with his hand, if necessary. In some existing designs, half-round shaped covers
allow for easier assembly of the suspension means and prevent this problem. Although
this is a simple solution, the production of such a part requires a mold. Mold production
increases the average cost of the part, especially when not very high volumes are
produced.
[0007] Furthermore,
CN216889647U shows a typical construction according to the state of the art. Here, the deflection
pulley is held by an extension which protrudes upwards from the actual cross beam
of the supporting structure that carries the mass bodies. In this way, the deflection
pulley requires considerable free space in the shaft head. Once more, if the counterweight
is still to be as compact as possible in the vertical direction because there is little
or no space in the area of the shaft head and pit, then the counterweight may have
to be fitted with mass bodies that have a higher specific weight than the usual ones
that are mostly made out of steel.
THE OBJECT OF THE INVENTION
[0008] In the light of this, it is the object or "task" of the invention to provide a counterweight
which - for a given width - is particularly compact in the vertical direction.
THE SOLUTION ACCORDING TO THE INVENTION
[0009] This task is solved by a device with the features of claim 1.
[0010] According to the invention, a counterweight for a suspension means elevator (in German:
Tragmittelaufzug) for a complete or partial compensation of the weight force with
which an elevator car loads its suspension means is proposed. Said suspension means
preferably consist of one or more ropes or belts. The counterweight comprises a supporting
structure with at least one cross beam which is consisting of one or more parts. This
"cross beam" is not always but in most cases a beam whose greatest longitudinal extension
extends transversely or substantially perpendicularly to the direction in which the
counterweight moves up and down the elevator shaft during intended operation, and
which extends over the major part of the width of the counterweight or preferably
extends substantially from one outer edge of the counterweight to the other outer
edge of the counterweight.
[0011] Said supporting structure supports at least one mass body and at least one deflection
pulley for the suspension means, wherein the deflection pulley is rotating about an
axis which is coaxial or parallel to the longitudinal axis of the cross beam. Said
longitudinal axis is the axis in the direction of the greatest longitudinal extension
of the cross beam.
[0012] The counterweight according to the invention is characterized in that the at least
one deflection pulley is housed at least partially - ideally predominantly or substantially
completely - in the cross beam.
[0013] "Housed in the cross beam" in a broader sense means that the rotational axis of the
at least one deflection pulley is running inside the box that the cross beam spans,
wherein the cross beam is preferably directly connected with one longitudinal beam
on each horizontal side and the cross beam is preferably not or not essentially protruding
the longitudinal beam in the vertical direction or only protruding the longitudinal
beam by at most 30 cm in the vertical direction.
[0014] In the narrower sense "housed in the cross beam" according to the invention means
that the at least one deflection pulley is at least partially and preferably predominantly
or substantially completely enclosed by the cross beam or the box that the cross beam
spans. It is preferred that the at least one deflection pulley protrudes the cross
beam or the box that the cross beam spans - preferably on two opposing vertical sides
of the cross beam - by at most 20% of the diameter of the respective deflection pulley.
Ideally, the respective deflection pulley protrudes the cross beam or the box that
the cross beam spans only so far that the suspension means can pass the vertical sides
of the cross beam unhindered, in some cases with the safety distance commanded by
the German elevator standards.
[0015] Therefore, a very compact design in the vertical direction can be ensured, as the
at least one deflection pulley is not protruding the cross beam in the vertical direction
and therefore the direction in which the counterweight is driven up and down.
PREFERRED DESIGN OPTIONS
[0016] Preferably, the cross beam has at least one window, preferably as a cutout or aperture,
through which the deflection pulley projects outwardly and therefore beyond the side
surface in which the window is located. This ensures a more desired and unhindered
course of the suspension means.
[0017] Furthermore, it is preferred that the window is at least partially covered by a protective
plate that spans the window with clearance, in such a way that the suspension means
running onto or off the deflection pulley can pass unhindered - or essentially unhindered
through the cross beam's outer surface surrounding the window and the inner surface
of the protective plate, ideally in such a way that the suspension means closes off
the major part of the free opening cross section remaining at the top between the
cross beam and the protective plate. The protective plate helps to ensure that as
far as possible no foreign bodies can stray into the area of the deflection pulley
and the suspension means running around it. The term "protective plate" does not imply
any material specification, but it may be made of plastic or preferably of metal.
[0018] It is preferred that two bearing plates are arranged in the cross beam, each of which
holds a free end of a deflection pulley axle. The axle of the deflection pulley can
thus be supported in the immediate vicinity of the deflection pulley, which keeps
its deflection small. Said bearing plate preferably is a bracket, preferably designed
as a sheet metal with several bends.
[0019] It is preferred that at least one, preferably all, bearing plates are preferably
bolted to the cross beam by means of elongated holes in such a way that the bearing
plates can be displaced - parallel to the longitudinal axis of the cross beam- within
the cross beam in such a way that the deflection pulley axle disengages therefrom.
This results in a considerably simplified mountability and dismountability.
[0020] Furthermore, it is preferred that the respective bearing plate is a, preferably substantially
rectangular, metal sheet which is bent by about 90° in each case at least along its
opposing vertical sides and ideally also along its upper horizontal side. This ensures
the needed stability, buckling stability and easier fixability to the cross beam.
[0021] It is preferred that the cross beam is closed at the top, at least in the area in
which it receives the at least one deflection pulley. This is as to prevent objects
falling down the shaft, such as bolts or nuts slipped out of the hands of the service
technician working on the car roof, can fall into the cross beam in the area of the
deflection pulley and then get jammed between the deflection pulley and the cross
beam or even be drawn into the gap between the suspension means running onto the deflection
pulley and the deflection pulley. Same applies in regard to debris including (especially
in winter time) little stones which may pass the slight gap between the sill of the
car body and the adjacent wall of the elevator shaft, in order to fall down the elevator
shaft hereinafter.
[0022] It is preferred that the cross beam consists of several - preferably two - sheets,
which are connected to one another at or in the area of their horizontal ends by a
longitudinal beam in each case. Said "longitudinal beam" is a beam whose greatest
longitudinal extent extends - at least substantially - parallel the direction in which
the counterweight moves up and down the elevator shaft during intended operation and
therefore in the vertical direction.
[0023] It is preferred that the sheets forming the cross beam are bent along their horizontal
sides. That way a stability and/or strength increase can be ensured.
[0024] It is also preferred that the bearing plates are held in position on the cross beam
by direct positive interaction (i. e. not only indirectly by bolts) with the cross
beam, preferably in that the bearing plates - ideally with their own bend - rest directly
against a bend of the cross beam. This ensures a particularly good protection against
the deflection pulley bearing shifting inside the cross beam in the event of an overload
occurring outside regular operation.
[0025] Furthermore, it is preferred that a guide plate for the suspension means is provided
immediately below each deflection pulley, extending from an area immediately below
one window in the cross beam to an area immediately below the opposite window in the
cross beam, and thereby preferably approaches the underside of the deflection pulley
at least locally to such an extent that the suspension means cannot move sideways
out of their seat on the deflection pulley. This facilitates the mounting of the suspension
means, as the end of the suspension means can be pushed in at one window and then
comes out again by itself at the opposite window. Furthermore, this ensures special
safety against unintentional slipping of the suspension means out of their seat on
the deflection pulley.
[0026] It is also preferred that the guide plate for the suspension means approximates the
shape of the deflection pulley by multiple folding. This results in a simpler manufacturability,
as there is no pressing tool required to impress a partially cylindrical recess onto
the guide plate.
[0027] Further possible configurations, modes of operation and advantages result from the
dependent claims and/or the subsequent description of the exemplary embodiment and/or
with reference to the figures.
FIGURE LIST
[0028]
Figure 1 shows the upper part of a counterweight according to the invention in three-dimensional
view.
Figure 2 shows the upper part of a counterweight according to the invention in three-dimensional
view as in Figure 1, but without one sheet of the cross beam.
Figure 3 shows - analogous to Figure 2 - the upper part of a counterweight without
one sheet of the cross beam, but in two-dimensional front view and with the bearing
plates being displaced in such a way that the deflection pulley axle is disengaged
therefrom.
Figure 4 shows a section of the upper part of the counterweight according to the invention
in two-dimensional side view.
PREFERRED EMBODIMENT
[0029] Fig. 1 to Fig. 4 show a preferred embodiment of the counterweight 1 according to
the invention.
[0030] The counterweight 1 preferably comprises a supporting structure 2 with at least one
cross beam 3 on top of the counterweight 1, facing the shaft ceiling, and at least
two longitudinal beams 12 that are connected to the cross beam 3 at or in the area
of its horizontal ends. The counterweight 1 also comprises mass bodies 4 in order
to ensure the desired weight of the counterweight 1.
[0031] The cross beam 3 preferably consists of two separate sheets 14 which are connected
to one another by said longitudinal beams 12. Furthermore, preferably each sheet 14
of the cross beam 3 comprises at least one window 7, also dependent on the number
of deflection pulleys 5 being used. In the shown preferred embodiment four deflection
pulleys 5 are used, wherein two deflection pulleys 5 are arranged right beside each
other and two deflection pulleys 5 protrude one window 7, which is why two windows
7 on each sheet 14 of the cross beam 3 are provided. Furthermore, the windows 7 are
preferably arranged in such a way, that the windows 7 facing each other and therefore
on another sheet 14 are corresponding to each other, preferably symmetrically identical
(see Fig. 4).
[0032] The deflection pulleys 5 are housed in the cross beam 3 and only slightly protrude
the outside surface of the cross beam 3 through the lateral windows 7 (see Fig. 1).
The windows 7 are preferably at least partially covered by a protective plate 8 in
order to prevent possible hand injury and prevent the suspension means from coming
out of the groove on the sides.
[0033] Preferably the protective plates themselves have little windows or a mesh-like structure
allowing visual inspection of the covered portion of the suspension means.
[0034] While the preferred U-shaped sheets 14 of the cross beam 3 create a robust structure,
their upper bending 15 provides additional structural security by preventing upward
movement with shape bond. The upper bending 15 also covers the deflection pulleys
5 in a sufficient area, eliminating the need for additional protection against falling
parts.
[0035] Figure 2 shows the inside of the cross beam 3 by showing it without the front sheet
14. The axle 10 of the pulleys 5 or the pulley group is connected to a bearing plate
9 at both ends. The bearing plate 9 is connected to the cross beam 3 or its sheets
14 with the bends on both sides and makes the structural integrity of the cross beam
3 even stronger. Its upper bending preferably touches on the upper bending 15 of the
sheets 14, making the upward movement of the pulley group physically impossible. In
this way, additional security is provided to the bolt connections.
[0036] Thanks to the elongated holes 11 in the cross beam sheets 14, the bearing plates
9 can be moved outwards during assembly and disassembly. This makes both assembly
and disassembly much easier. Even if it is preferred, the elongated holes 11 need
not to be mandatorily in the cross beam sheets 14, but also could be in the bearing
plates 9 instead.
[0037] The guide plate 13 is a simple part that preferably can be produced easily with conventional
sheet metal bending machines and does not require molds. Although it is an easy part
to manufacture, it fulfills several functions thanks to its special shape.
[0038] First, it prevents the suspension means from coming out of the groove of the pulley.
[0039] Second, at the suspension means assembly, when the installer pushes the suspension
means under the pulley 5, it provides the suspension means to come out of the opposite
window 7. Thanks to the correct angles in the guide plate 13, it is not possible for
the suspension means end to get stuck in any place and not come out. The shape guides
the suspension means towards the window 7.
[0040] Third, when a pulley replacement is required for maintenance, a sheet 14 of the cross
beam 3 is removed, and the bearing plates 9 are moved outwards on the elongated holes
11 (see Fig. 3). At this stage, thanks to its nest shape (see Fig. 4), it allows the
pulleys 5 to remain in approximately the same position temporarily. It acts as a temporary
holder so that the pulleys 5 do not fall down or forward. Fig. 1 and Fig. 3 also show
the rotational axis 6 of the deflection pulleys 5, wherein the rotational axis 6 in
Figure 3 is only an imaginary rotational axis, as this is not the intended position
for the rotation, because the axle 10 is not held by the bearing plates 9 anymore.
REFERENCE LIST
[0041]
- 1
- Counterweight
- 2
- Supporting structure
- 3
- Cross beam
- 4
- Mass body
- 5
- Deflection pulley
- 6
- Rotational axis of the deflection pulley
- 7
- Window
- 8
- Protective plate
- 9
- Bearing plate
- 10
- Axle of the deflection pulley
- 11
- Elongated hole
- 12
- Longitudinal beam
- 13
- Guide plate
- 14
- Sheet of the cross beam
- 15
- Upper bending
1. A counterweight (1) for a suspension means elevator for a compensation of the weight
force with which a car loads its suspension means, wherein the counterweight (1) comprises
a supporting structure (2) with at least one cross beam (3), which supports the at
least one mass body (4) and at least one deflection pulley (5) for the suspension
means, wherein the deflection pulley (5) is rotating about an axis (6) which is coaxial
or parallel to the longitudinal axis of the cross beam (3), characterized in that the at least one deflection pulley (5) is housed in the cross beam.
2. The counterweight (1) for a suspension means elevator according to claim 1, characterized in that the cross beam (3) has at least one window (7) through which the deflection pulley
(5) projects outwardly.
3. The counterweight (1) according to claim 1 or 2, characterized in that the window (7) is at least partially covered by a protective plate (8) that spans
the window (7) with clearance, in such a way that the suspension means running onto
or off the deflection pulley (5) can pass unhindered through the cross beam's (3)
outer surface surrounding the window (7) and the inner surface of the protective plate
(8), ideally in such a way that the suspension means closes off the major part of
the free opening cross section remaining at the top between the cross beam (3) and
the protective plate (8).
4. The counterweight (1) for a suspension means elevator according to one of the preceding
claims, characterized in that two bearing plates (9) are arranged in the cross beam (3), each of which holds a
free end of a deflection pulley axle (10).
5. The counterweight (1) for a suspension means elevator according to one of the preceding
claims, characterized in that at least one, preferably all, bearing plates (9) are preferably bolted to the cross
beam (3) by means of elongated holes (11) in such a way that the bearing plates (9)
can be displaced within the cross beam (3) in such a way that the deflection pulley
axle (10) disengages therefrom.
6. The counterweight (1) for a suspension means elevator according to the immediately
preceding claim, characterized in that the respective bearing plate (9) is a, preferably substantially rectangular, metal
sheet which is bent by about 90° in each case at least along its opposing vertical
sides and ideally also along its upper horizontal side.
7. The counterweight (1) according to one of the preceding claims, characterized in that the cross beam (3) is closed at the top, at least in the area in which it receives
the at least one deflection pulley (5).
8. The counterweight (1) according to one of the preceding claims, characterized in that the cross beam (3) consists of several sheets (14), which are connected to one another
at or in the area of their horizontal ends by a longitudinal beam (12) in each case.
9. The counterweight (1) according to the immediately preceding claim, characterized in that the sheets (14) forming the cross beam (3) are bent along their horizontal sides.
10. The counterweight (1) according to the immediately preceding claim in conjunction
with claim 6, characterized in that the bearing plates (9) are held in position on the cross beam (3) by direct positive
interaction with the cross beam (3), preferably in that the bearing plates (9) rest directly against a bend of the cross beam (3).
11. The counterweight (1) according to one of the preceding claims, characterized in that a guide plate (13) for the suspension means is provided immediately below each deflection
pulley (5), extending from an area immediately below one window (7) in the cross beam
(3) to an area immediately below the opposite window (7) in the cross beam (3) and
thereby preferably approaches the underside of the deflection pulley (5) at least
locally to such an extent that the suspension means cannot move sideways out of its
seat on the deflection pulley (5).
12. The counterweight (1) according to the immediately preceding claim, characterized in that the guide plate (13) for the suspension means approximates the shape of the deflection
pulley (5) by multiple folding.
13. Elevator having a car which is connected to a counterweight via a suspension means
preferably looped around a traction sheave, the car and the counterweight being guided
on guide rails and being movable in the vertical direction, characterized in that the counterweight is a counterweight (1) according to one of the preceding claims.