Yoke assembly for suspending an elevator car or a counterweight in a shaft of an elevator

A yoke assembly for suspending an elevator car or a counterweight in a shaft of an elevator has a yoke adapted to be mechanically coupled to the elevator car or the counterweight. The yoke has a height with respect to a height axis and a length with respect to a longitudinal axis orthogonal to the height axis; a pulley for suspending the yoke, wherein the pulley has a diameter equal to or less than the height of the yoke and is attached to the yoke so as to be rotatable about an axis of rotation whose position with respect to the height axis is such that the pulley does not protrude beyond the yoke in either direction of the height axis; wherein, when the yoke is suspended in the shaft, the height axis is a vertical axis and the axis of rotation is a horizontal axis.

FIELD OF THE INVENTION

The invention relates to a yoke assembly for suspending an elevator car or a counterweight in a shaft of an elevator. The invention further relates to an elevator.

BACKGROUND OF THE INVENTION

An elevator car (or a counterweight) may be suspended in a shaft of an elevator by means of a yoke as an upper part of a frame that carries the elevator car (or the counterweight). The yoke may include one or more pulleys for suspending the yoke by means of one or more tension members, such as a cable or a belt. Usually, the pulleys are placed above the yoke.

EP 3 085 656 A1 describes a yoke as part of a support structure for supporting an elevator car or a counterweight in a shaft of an elevator. The yoke comprises a pulley and two parallel beams separated from each other by a horizontal gap. The pulley is arranged within the gap so that part of it protrudes beyond a lower end of the yoke.

US 2017/0283221 A1 describes a counterweight for an elevator. The counterweight comprises a counterweight frame and a counterweight hitch for suspending the counterweight in a shaft of the elevator by means of a plurality of tension members. The counterweight hitch is attached to the top of the counterweight frame.

SUMMARY OF THE INVENTION

It may be seen as an objective of the invention to provide a yoke assembly with reduced height. This makes it possible to reduce the height of the shaft head accordingly.

Another objective of the invention may be to provide a corresponding elevator.

These objectives may be achieved by the subject matter of the independent claims. Advantageous embodiments are defined in the dependent claims, as well as in the following description and the attached drawings.

A first aspect of the invention relates to a yoke assembly for suspending an elevator car or a counterweight in a shaft of an elevator. The yoke assembly comprises: a yoke adapted to be mechanically coupled to the elevator car or the counterweight, wherein the yoke has a certain height with respect to a height axis and a certain length with respect to a longitudinal axis orthogonal to the height axis; a pulley for suspending the yoke in the elevator shaft by means of a tension member, wherein the pulley has a diameter equal to or less than the height of the yoke and is attached to the yoke so as to be rotatable about an axis of rotation whose position with respect to the height axis is such that the pulley does not protrude beyond the yoke in either direction of the height axis; wherein, when the yoke is suspended in the shaft, the height axis is a vertical axis and the axis of rotation is a horizontal axis.

The yoke assembly makes it possible to reduce the height of the shaft head (also referred to as overhead), as there is no additional structure above or below the yoke. Thus, the shaft length can be significantly reduced, which may reduce the costs for the building in which the elevator is to be installed.

It is understood that the length of the yoke is significantly greater than its height. For example, the length may be at least twice, at least four times, or at least ten times the height.

For example, the (outer) diameter of the pulley may be equal to or less than 90% of the height of the yoke. In some cases, the diameter may be equal to or less than 75% of the height of the yoke.

A “pulley” as described above and below may be a single pulley or a combination of at least two single pulleys having the same axis of rotation. The single pulleys may have identical properties, e.g., have the same dimensions. However, they may also differ from each other, e.g., in their dimensions.

The yoke assembly may also comprise more than one pulley, e.g., two, three, four, or more than four pulleys having identical or different (e.g., parallel) axes of rotation.

In a preferred embodiment, the vertical position of the axis of rotation (i.e., its position with respect to the height axis) may be equal or close to the vertical position of a centerline of the yoke. The term “close” may mean, for example, a deviation of 30 cm or less, preferably 10 cm or less, more preferably 1 cm or less, between the two vertical positions.

A second aspect of the invention relates to an elevator. The elevator comprises: an elevator car and a yoke assembly as described above and below, wherein the yoke is mechanically coupled to the elevator car and suspended in a shaft of the elevator by means of a tension member that at least partially surrounds the pulley; and/or a counterweight and a yoke assembly as described above and below, wherein the yoke is mechanically coupled to the counterweight and suspended in the shaft by means of a tension member that at least partially surrounds the pulley.

A tension member may be, for example, a cable, a belt, or a combination of at least two of these examples.

As mentioned above, such an elevator may have a significantly reduced shaft head height as compared to conventional elevators where the pulley protrudes, or the pulleys protrude, beyond the yoke in one or both directions of the (vertical) height axis.

When the tension member is a belt, the pulley may have a diameter of less than 130 mm and preferably less than 100 mm. This further helps to optimize the use of space.

Embodiments of the invention may be regarded as based on the ideas and findings described below without limiting the scope of the invention.

According to an embodiment, the axis of rotation may be orthogonal or parallel to the longitudinal axis.

According to an embodiment, the pulley may be arranged next to the yoke so as to face a longitudinal side of the yoke. In other words, the pulley may be located completely outside the yoke while facing an outer side of a yoke part, such as a beam or a side wall, whose longitudinal axis is parallel to the longitudinal axis of the yoke. In this case, the axis of rotation of the pulley may be orthogonal to the longitudinal axis of the yoke (part). However, the axis of rotation may also be parallel to it.

According to an embodiment, the yoke may comprise two yoke parts having longitudinal axes parallel to the longitudinal axis of the yoke. In this case, the pulley may be arranged within a (horizontal) gap between the two yoke parts. In other words, the pulley may be located completely inside the yoke. This may reduce the width of the yoke (with respect to a transverse axis orthogonal to both the height axis and the longitudinal axis of the yoke) as compared to embodiments where the pulley is arranged next to the yoke. In particular, the position of the axis of rotation of the pulley with respect to the height axis may be such that the pulley does not protrude beyond one or both of the yoke parts in either direction of the height axis. A “yoke part” may be, for example, a beam or a side wall of the yoke. The two yoke parts may be parallel to each other. In other words, they may have substantially the same position with respect to the height axis, but different positions with respect to the transverse axis.

According to an embodiment, the yoke assembly may further comprise a further pulley for suspending the yoke in the shaft by means of a tension member, wherein the further pulley has a diameter equal to or less than the height of the yoke and is attached to the yoke so as to be rotatable about a further axis of rotation whose position with respect to the height axis is such that the further pulley does not protrude beyond the yoke in either direction of the height axis.

The pulley and the further pulley may have identical properties, e.g., have the same dimensions and/or the same axis of rotation. However, they may also differ from each other, e.g., in their dimensions and/or axis of rotation.

The pulley and the further pulley may have the same position or different positions with respect to the height axis (as long as none of them protrudes beyond the yoke in either direction of the height axis). In some embodiments, both pulleys may have the same position with respect to the longitudinal axis and different positions with respect to a transverse axis orthogonal to both the longitudinal axis and the height axis. In some other embodiments, the pulleys may have different positions with respect to the longitudinal axis and the same position with respect to the transverse axis.

The yoke assembly may also comprise more than one further pulley, e.g., two, three, four, or more than four further pulleys.

According to an embodiment, the further pulley may be arranged next to the yoke so as to face a longitudinal side of the yoke. In this case, the pulley and the further pulley may face different longitudinal sides of the yoke. In other words, the further pulley, as well as the pulley, may be located completely outside the yoke, wherein the yoke, in its longitudinal direction, may run through a (horizontal) gap between the two pulleys. Additionally, the axis of rotation of each pulley may be orthogonal to the longitudinal axis of the yoke. Furthermore, both pulleys may have the same axis of rotation.

According to an embodiment, the further pulley may be arranged within the (horizontal) gap between the two yoke parts. In other words, the further pulley, as well as the pulley, may be located completely inside the yoke. This may reduce the width of the yoke (with respect to the transverse axis) as compared to embodiments where the pulleys are arranged next to the yoke.

According to an embodiment, the axis of rotation may be parallel to or collinear (i.e., identical) with the further axis of rotation.

According to an embodiment, the yoke assembly may further comprise a support structure for attaching the pulley and the further pulley to the yoke. The support structure may comprise: a base plate having a first attachment portion and a second attachment portion; a connecting plate having a first opening and a second opening and being attached to both the yoke and the base plate so that the first opening faces the first attachment portion and the second opening faces the second attachment portion; a first bracket attached at one end to the first attachment portion and extending from the first attachment portion through the first opening so that another end of the first bracket protrudes from the first opening, wherein the pulley is rotatably attached to the protruding end of the first bracket; a second bracket attached at one end to the second attachment portion and extending from the second attachment portion through the second opening so that another end of the second bracket protrudes from the second opening, wherein the further pulley is rotatably attached to the protruding end of the second bracket.

Such a support structure is stiff enough to ensure that the axes of rotation of the pulleys remain correctly aligned during operation of the elevator. Using plates to build the support structure may also reduce the manufacturing costs as compared to using more complex parts, such as milled or cast parts.

A “plate” as described above and below may be a metal plate. However, other plate materials may also be used.

The base plate and the connecting plate may be parallel to each other.

In some embodiments, the yoke, preferably with its bottom end, may touch the connecting plate in an area between the first bracket and the second bracket.

In some other embodiments, the yoke, preferably with its bottom end, may touch the connecting plate in one or more areas extending along its entire length or width. Such an area may be, for example, adjacent to one of the longitudinal edges of the connecting plate.

According to an embodiment, a (vertical) gap between the base plate and the connecting plate may be at least partially filled with a rubber material that mechanically couples the base plate to the connecting plate. This may significantly reduce unwanted vibrations and/or noise during operation of the elevator.

According to an embodiment, the support structure may further comprise a u-shaped profile. In this case, the base plate may be combined with the u-shaped profile to form a hollow, preferably rectangular, profile, e.g., by bolting and/or bonding (preferably welding) the parts together. This may significantly increase the stability and/or stiffness of the support structure (as compared, for example, to an embodiment where the base plate is a single plate) without excessively increasing the weight and/or the manufacturing costs of the support structure.

According to an embodiment, the first bracket may comprise a first plate and a second plate parallel to the first plate. In this case, the pulley may have an axle attached at its first end to the first plate and at its second end to the second plate.

According to an embodiment, the second bracket may comprise a first plate and a second plate parallel to the first plate. In this case, the further pulley may have an axle attached at its first end to the first plate and at its second end to the second plate.

Such a bracket can be made very easily.

According to an embodiment, the first bracket may further comprise a third plate and a fourth plate parallel to the third plate. In this case, the first plate and the second plate of the first bracket may be interconnected on a first side by the third plate and on a second side opposite the first side by the fourth plate.

According to an embodiment, the second bracket may further comprise a third plate and a fourth plate parallel to the third plate. In this case, the first plate and the second plate of the second bracket may be interconnected on a first side by the third plate and on a second side opposite the first side by the fourth plate.

This may significantly increase the stability and/or stiffness of the respective bracket without excessively increasing the weight and/or the manufacturing costs of the support structure.

For example, the four plates of the respective bracket may be bolted and/or bonded (preferably welded) together.

According to an embodiment, the yoke assembly may further comprise a frame for carrying the elevator car or the counterweight. In this case, the yoke may be a part of the frame. The yoke may be located above the elevator car when suspended in the shaft as part of the frame carrying the elevator car or above the counterweight when suspended in the shaft as part of the frame carrying the counterweight. In other words, the yoke may be an upper part of the frame when the frame is arranged in the shaft so as to be movable in a vertical direction.

DETAILED DESCRIPTION OF THE INVENTION

The figures are merely schematic and not to scale. Identical reference signs in the drawings denote identical features or features having the same effect.

FIG.1shows an elevator1having a shaft2in which an elevator car3is suspended by means of a yoke assembly5. The yoke assembly5comprises a yoke7mechanically coupled to the elevator car3. The yoke7has a height H with respect to a vertical height axis x and a length L with respect to a horizontal longitudinal axis y. Attached to the yoke7is a pulley9having a diameter D equal to or less than the height H. Preferably, the diameter D is 90% or less (or even 75% or less) of the height H. The pulley9is rotatable about a horizontal axis of rotation r whose x-position is such that the pulley9does not protrude beyond the yoke7in either direction of x. In particular, the x-position of r may be equal or close to the x-position of a centerline c of the yoke7, as shown here. For example, the deviation between the two x-positions may be less than 30 cm, less than 10 cm, or even less than 1 cm. In addition, r is orthogonal to y.

The yoke7is suspended in the shaft2by means of a tension member11(e.g., a cable, a belt, or a combination of at least two of these examples), which surrounds a part of a circumferential surface of the pulley9.

The tension member11couples the elevator car3to a counterweight13and is driven by a traction pulley15coupled to a motor. Thus, moving the traction pulley15in one direction causes the elevator car3and the counterweight13to move vertically in opposite directions.

In this example, the yoke assembly5further comprises a frame17that carries the elevator car3. The yoke7, as an upper part of the frame17, is located above the elevator car3. The yoke7is coupled at each of its ends by an upright19to a bottom21that carries the elevator car3.

Like the elevator car3, the counterweight13may be suspended in the shaft2by means of a yoke assembly5. In this example, the axis of rotation r of the pulley9is parallel to y, i.e., orthogonal to a transverse axis z corresponding to a width direction of the yoke7. However, r may also be orthogonal to y. The yoke7is located above the counterweight13.

Although not shown inFIG.1, a frame17may be part of the yoke assembly5of the counterweight13and carry the counterweight13in the same or a similar way as it carries the elevator car3.

With respect to the longitudinal axis y, the axis of rotation r may be positioned above the center of gravity of the elevator car3(more precisely of a combination of the elevator car3and the yoke assembly5) or above the center of gravity of the counterweight13(more precisely of a combination of the counterweight13and the yoke assembly5). This ensures that the suspended elevator car3, or the suspended counterweight13, is well balanced. However, in some cases, the axis of rotation r may also be horizontally offset to the respective center of gravity.

Such an elevator may have a significantly reduced shaft head height as compared to conventional elevators where the pulley usually protrudes beyond the yoke in one or both directions of the height axis x.

As shown inFIG.2,FIG.3, andFIG.5, the pulley9may be arranged next to the yoke7so as to face one of its longitudinal sides.

Alternatively, as shown inFIG.7, the pulley9may be located completely inside the yoke7, more specifically in a horizontal gap23(see alsoFIG.3andFIG.5) between two parallel yoke parts25, such as beams or side walls, which may be plate-shaped, for example.

As shown inFIG.2toFIG.7, the yoke assembly5may additionally comprise a further pulley27for suspending the yoke7in the shaft2by means of a tension member11. In this case, the pulleys9,27may each be attached to a support structure29in such a way that their respective axes of rotation r are collinear with each other.

However, in some cases, the axes of rotation r may also be parallel to each other.

The support structure29, in turn, is attached to the yoke7, here to a bottom end of each of the two yoke parts25.

As shown inFIG.2,FIG.3, andFIG.5, the pulleys9,27may be coupled by the support structure29to the yoke7in such a way that they face different longitudinal sides of the yoke7and the collinear axes of rotation r are orthogonal to the longitudinal axis y.

As an alternative (seeFIG.7), the pulleys9,27may be coupled by the support structure29to the yoke7in such a way that they are located completely inside the yoke7, i.e., in the horizontal gap23, and the collinear axes of rotation r are parallel to the longitudinal axis y.

In both cases, the pulleys9,27should be arranged symmetrically to the respective center of gravity (see also above).

Each of the pulleys9,27may be a single pulley or a combination, e.g., a stack, of two (as shown here) or even more than two single pulleys rotatable about the same axis of rotation r. In this example, the single pulleys of each pulley9,27have the same diameter D and the same width. However, they may also differ from each other to some extent in some cases.

In this example, the support structure29is a combination of a plurality of plates, namely a base plate31and a connecting plate33, which are preferably metal plates.

The base plate31has a first attachment portion35aand a second attachment portion35b. The connecting plate33has a first opening37aand a second opening37b. Each of the openings37a,37bconnects a bottom side with a top side of the connecting plate33. The plates31,33are arranged in such a way that the first opening37afaces the first attachment portion35aand the second opening37bfaces the second attachment portion35b.

The plates31,33may be parallel to each other. Furthermore, they may be separated from each other by a vertical gap39(seeFIG.3) of a defined height with respect to the height axis x. For example, the plates31,33may be aligned with each other by means of a plurality of bolts41(here four bolts) connected at each of their ends to one of the plates31,33.

The support structure29is connected, e.g., bolted and/or bonded (especially welded), to the yoke7via the connecting plate33. In this example, the connecting plate33is connected to the yoke7so that the top side of the connecting plate33touches a bottom side of each yoke part25. This means that the connecting plate33, with respect to the height axis x, is located below the yoke7and between the base plate31and the yoke7.

The support structure29further comprises a first bracket43afor holding the pulley9and a second bracket43bfor holding the further pulley27.

The first bracket43ais attached at one end to the first attachment portion35aand extends from the first attachment portion35athrough the first opening37aso that its other end protrudes from the first opening37a. The pulley9is rotatably attached to the protruding end of the first bracket43a.

The second bracket43bis attached at one end to the second attachment portion35band extends from the second attachment portion35bthrough the second opening37bso that its other end protrudes from the second opening37b. The further pulley27is rotatably attached to the protruding end of the second bracket43b.

Preferably, each pulley9,27is attached to its respective bracket so as not to protrude into the vertical gap39.

In this example (seeFIG.5andFIG.6), each bracket43a,43bis composed of a first plate45a, a second plate45b, a third plate45c, and a fourth plate45d. The first plate45aand the second plate45bof each bracket43a,43bare parallel to each other. The respective pulley9,27is arranged within a horizontal gap between the two plates45a,45band has its axle attached at one end to the first plate45aand at the other end to the second plate45b.

Each plate45a,45bmay be inserted, e.g., pressed, with one of its ends in one of a plurality of recesses47in the base plate31within one of the attachment portions35a,35b. In addition, the plates45a,45bare bonded, preferably welded, to the base plate31.

Furthermore, the first plate45aand the second plate45bof each bracket43a,43bare interconnected on a first side by the respective third plate45cand on a second side opposite the first side by the respective fourth plate45d. The plates45c,45dof each bracket43a,43bare parallel to each other. This increases the stability and/or stiffness of the respective bracket, which improves the accuracy with which the axes of rotation r can be aligned with each other.

As shown inFIG.2,FIG.3, andFIG.5, the yoke parts25may touch the connecting plate33in an area between the first bracket43aand the second bracket43bwhile running, in their longitudinal direction, through a gap between the two brackets43a,43b(and thus between the two pulleys9,27).

Alternatively, as shown inFIG.7, the yoke parts25may touch the connecting plate33over its entire length (or width), preferably in areas adjacent to the longitudinal (or transverse) edges of the connecting plate33.

To reduce unwanted vibrations and/or noise during operation of the elevator1, i.e., when the elevator car3and the counterweight13are moved vertically by moving the tension member(s)11, the vertical gap39may be at least partially filled with a rubber material49(seeFIG.5andFIG.6) that mechanically couples the base plate31to the connecting plate33by touching both the bottom side of the connecting plate33and a top side of the base plate31.

To further increase the overall stability and/or stiffness of the support structure29, the base plate31may be combined with a u-shaped profile51(seeFIG.5andFIG.6) to form a hollow profile, which may have a rectangular or square cross section, for example. Preferably, the base plate31and the u-shaped profile51are bonded, e.g., welded, together. Alternatively, the hollow profile is made as a single part. In this case, the base plate31forms a flat upper part of the hollow profile.

The yoke parts25may be interconnected by a plurality of links55, such as plates or rods, to form a stable frame, as shown inFIG.2andFIG.7.

Further (active) components of the elevator1, such as brake components57for stopping the elevator car3or the counterweight13, may be attached to the yoke7(seeFIG.2,FIG.3,FIG.5, andFIG.7). Such components are preferably arranged at least partially in the horizontal gap23to save space.

Generally, the position of the axes of rotation r should be as close as possible to the centerline c of the yoke7. To achieve this, a bearing block that supports two pulleys9,27may be split in the center to leave some space for the yoke7, resulting in two bearing blocks, one for each pulley, on each side. The bearing blocks may be interconnected by a plate or a combination of two or more plates, which ensures correct alignment of the axes of rotation r. The plate (or one of the combined plates) may be connected to the bottom of the yoke7. This also allows easy integration of a vibration damping device, such as the rubber material49, coupled to both pulleys.

Finally, it is noted that terms such as “comprising”, “including”, “having”, or “with” do not exclude other elements or steps and that the indefinite article “a” or “an” does not exclude a plurality. It is further noted that features or steps described with reference to one of the above embodiments may also be used in combination with features or steps described with reference to any other of the above embodiments. Reference signs in the claims are not to be construed as limiting the scope of the claims.