Elevator guide rail

Abstract

The present disclosure relates to an elevator guide rail (100) comprising a head portion (110) and a foot portion (120), wherein a recess is formed in a base surface of the foot portion.

Description

[0001] The present disclosure generally relates to an elevator guide rail. Particularly, the present disclosure relates to a lightweight guide rail for an elevator.

[0002] Guide rails for a passenger or service elevator provide for guiding the car of an elevator or the counterweight of the elevator along the moving direction of the car or the counterweight. The dimensional characteristics including tolerances as well as grades and quality of the steel for such guide rails are standardised, for example in norm ISO 7465:2007.

[0003] However, with increasing length of elevator shafts (e.g., due to an increasing height of buildings) the number of elevator guide rails to be installed in a building increases. The price for the raw material (e.g., steel) and manufacturing also increases. Thus, installing one or more elevators in a building becomes more and more expensive.

[0004] It is thus an object of the present disclosure to provide a cost-effective elevator guide rail.

[0005] According to a first aspect of the present disclosure, a guide rail for an elevator, in a cross-section thereof, comprises a head portion and a foot portion comprising a head surface substantially facing the head portion and a base surface arranged opposite to the head surface. In other words, the foot portion forms a flange with respect to the head portion.

[0006] Furthermore, the foot portion has a recess at the base surface. Providing a recess at the base surface at least in a part of the foot portion reduces the size of the foot portion. Thus, the weight of the elevator guide rail is reduced. This not only reduces the overall weight of elevator guide rails in a building, but also reduces the costs for each elevator guide rail due to the reduced amount of material (steel) required for the guide rail.

[0007] In an implementation variant, the recess, in the cross-section of the guide rail, can have a shape of a Gaussian distribution or a parabola or a shape of a portion of a triangle, circle or ellipse, for example. Thus, the base surface can have a recess of the varying depth. Alternatively, the recess, in the cross-section of the guide rail, can have a shape of a rectangle, so that the base surface can have a recess of constant depth.

[0008] In an implementation variant, the cross-section of the guide rail can be axially symmetric. This facilitates installation of the guide rail and improves stability of the guide rail.

[0009] In an implementation variant, the foot portion can extend in two lateral directions with respect to the head portion and forms two lateral edges. Thus, the foot portion forms two flanges arranged opposite to one another and with respect to a centre line running through the head portion. Furthermore, the recess is disposed between the two lateral edges.

[0010] In other words, the guide rail can have a T-shaped cross-section, and the base surface at the two lateral edges can be arranged in a common plane, while the base surface in the area of the recess is spaced apart from the common plane in a direction towards the head portion.

[0011] In an implementation variant, a thickness of the foot portion from a centre of the foot portion to the respective lateral edge is substantially the same. Thus, the head surface of the foot portion may be inclined, i.e., is further away from the common plane between the two lateral edges at the centre than at each of the two lateral edges. This allows that the foot portion has substantially the same thickness (measured in a direction substantially perpendicular to the common plane), although the recess is present.

[0012] Alternatively, the thickness of the foot portion from a centre of the foot portion increases towards each of the lateral edges. In other words, the foot portion is thicker at the outer / lateral edges compared to a centre part of the foot portion. As a mere example, the thickness of the foot portion can increase between 10 to 20% of a minimum thickness at the centre of the foot portion. According to a further example, the thickness of the foot portion can increase between 14 to 18% of the minimum thickness at the centre of the foot portion.

[0013] As a mere example, a guide rail T89 / B, according to the norm ISO 7465:2007, has a foot portion with a thickness decreasing from 11.1 mm at a centre to 7.9 mm at outer edges of the foot portion. The base surface of this standardised guide rail is flat.

[0014] Omitting material in the foot portion, according to the present disclosure, decreases the weight of the guide rail significantly. Furthermore, it allows that the thickness of the guide rail can be approximately 7.9 mm at the centre (instead of 11.1 mm) and throughout the foot portion up to the lateral edges.

[0015] Still with respect to a guide rail corresponding to T89 / B, but formed according to the present disclosure, the minimum thickness of the foot portion at the centre can vary between 5.8 to 6.8 mm, such as 6.2 mm, while the thickness at the outer / lateral edges of the foot portion can vary between 6.4 mm to 8.2 mm, such as 7.9 mm. Such foot portion allows a reduction of the weight of the guide rail of approximately 18 to 19%.

[0016] It is to be understood that a guide rail corresponding to another size, standardised according to the norm ISO 7465:2007, may have different thickness values or thickness ranges. Nevertheless, forming a recessed base surface of the foot portion allows reducing the weight of the guide rail likewise by approximately 15 to 20%.

[0017] In an implementation variant, in a longitudinal end section of the guide rail, a part of the base surface is flattened. At the longitudinal end section of the guide rail, a counter plate (also referred to as a fishplate) or the like is regularly mounted to the base surface in order to couple two guide rails to one another. Flattening the part of the base surface facilitates such coupling to the counter plate and increases the contacting surfaces at the respective lateral edges / flanges. However, the recess is still present, i.e., only a part at the lateral edges of the base surface is flattened.

[0018] In an implementation variant, the guide rail can further comprise at least one through hole through the foot portion in the longitudinal end section of the guide rail. Such through hole can be used to mount the guide rail to a counter plate or the like.

[0019] In an implementation variant, the through hole can be surrounded by a partial bore flattening the head surface. As the head surface may be inclined with respect to the common plane between the lateral edges, the partial bore facilitates contacting between a nut, washer or the like and the guide rail.

[0020] In an implementation variant, the guide rail can further comprise a notch in a front face of the guide rail, and / or a protrusion in a front face of the guide rail. The notch and protrusion in a front face allows coupling two guide rails to one another at their respective front faces (where one front face has a notch and the other front face has a protrusion), wherein the protrusion has a shape corresponding to the shape of the notch. Thus, the two guide rails can engage with one another, particularly with respect to the lateral direction.

[0021] In an implementation variant, the guide rail can further comprise an intermediate section between the head portion and the foot portion, and / or a tread formed at least at lateral surfaces of the head portion. The intermediate section, particularly a height of the intermediate section, may facilitate placing the tread in the right position in relation to the foot portion, i.e., in the right position within the elevator shaft. The tread of the guide rail may form a blade or surface on / along which a guiding component of the elevator car or counterweight glides / moves / runs / etc. Moreover, geometrical precision and a blank surface with low roughness is required for the tread at the head portion of the guide rail. This may be achieved by machining the head portion (or at least one or more surfaces thereof) and / or by cold-forming the head portion.

[0022] In an implementation variant, the head portion can extend from the foot portion, such as into an open space of the elevator shaft when the guide rail is mounted in the elevator shaft. The head portion may be arranged at an angle to the foot portion (particularly when viewing the cross-section of the guide rail). As a mere example, the angle between the head portion and foot portion can be 90° + / - 10°.

[0023] In an implementation variant, the guide rail can be manufactured by cold-forming a profile, e.g., a hot-formed steel bar. Cold-forming the bar can comprise cold-rolling or cold-drawing. This can be implemented by employing one or more propelled or non-propelled rollers that cold-roll at least a portion of the guide rail, and / or one or more fixed dies shaping the guide rail. Such cold-forming may employ several cold-forming steps. At least some of the roles or dies in this process are shaped in correspondence with the head surface and the base surface of the foot portion, particularly including one or more roles or dies forming the recess in the base surface of the foot portion.

[0024] In an implementation variant, the guide rail can be manufactured by hot-forming a raw material, such as a raw steel bar, e.g., hot-rolled or hot-drawn or hot-extruded or hot-forged. Such hot-forming may employ several hot-forming steps. At least some of the roles or dies in this process are shaped in correspondence with the head surface and the base surface of the foot portion, particularly including one or more roles or dies forming the recess in the base surface of the foot portion.

[0025] In an implementation variant, the guide rail can be manufactured by cold-forming and / or hot-forming a first stage guide rail, which has a flat base surface. Thereafter, the recess in the base surface is formed by, for example, machining, i.e., removing, material from the foot portion at the base surface.

[0026] The present disclosure is not restricted to the described aspects and variants in the described form and order. Specifically, the description of aspects and variants is not to be understood as a specific limiting grouping of features. It is to be understood that the present disclosure also covers combinations of the aspects and variants not explicitly described. Thus, each variant or optional feature can be combined with any other aspect, variant, optional feature or even combinations thereof.

[0027] In the following, the present disclosure will further be described with reference to exemplary embodiments illustrated in the figures, in which: Figure 1schematically illustrates a perspective view of a section of an exemplary elevator guide rail; Figure 2schematically illustrates a cross-sectional view of an exemplary elevator guide rail; Figure 3schematically illustrates details of a foot portion of an exemplary elevator guide rail; and Figure 4schematically illustrates a cross-sectional view of an exemplary elevator guide rail and mounting components.

[0028] In the following description, for purposes of explanation and not limitation, specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent to one skilled in the art that the present disclosure may be practiced in other implementations that depart from these specific details.

[0029] Figure 1 schematically illustrates a section of a guide rail 100, particularly a longitudinal end section of the guide rail 100. The guide rail 100, particularly for guiding an elevator, comprises a head portion 110 and a foot portion 120. The foot portion 120 comprises a head surface 121 and a base surface 122, which will be explained in more detail with respect to Figure 2.

[0030] Specifically, the head surface 121 substantially faces the head portion 110, and the base surface 122 is arranged opposite to the head surface 121. Furthermore, the foot portion 120 has a recess 130 at the base surface 122. While the head portion 110 extends substantially vertical (in the Z-axis direction) in the cross-section of the guide rail 100, the foot portion 120 extends substantially perpendicular (90° + / - 10°) thereto (i.e., substantially in the Y-axis direction, also referred to as the lateral direction).

[0031] The head portion 110 can form or comprise a tread 112 (also referred to as a blade or gliding surface or guiding surface) of the guide rail 100. A car or counterweight of the elevator (not illustrated) usually has a component connected thereto that runs along the guide rail 100, so that the car or counterweight is guided along its path up and down the elevator shaft. Such component may include rollers or gliders that contact the tread 112 of the head portion 110.

[0032] The head portion 110 can further be separated into a section forming the tread 112 of the guide rail 100 and an intermediate section 115. The intermediate section 115, particularly a length of the intermediate section 115 (in Z-axis direction), may hence solely facilitate placing the tread 112 in the right position in relation to the foot portion 120, i.e., in the right position within the elevator shaft.

[0033] The intermediate section 115 may have a smaller width (in Y-axis direction) than the remainder of the head portion 100 and, particularly, the portion forming the tread 112. It is to be noted that the protrusion illustrated in Figure 2 between the intermediate section 115 and the foot portion 120 may result solely from the (hot- / cold-) forming process, but is not necessary for the present disclosure. Thus, the transition from the intermediate section 115 to the head surface 121 may be smooth, i.e., without the illustrated protrusion.

[0034] The recess 130 (when contemplating the cross-section of the guide rail 100) can have a shape of a Gaussian distribution as illustrated. Alternatively, the recess 130 can have a shape of a parabola or the shape of a portion of a triangle, ellipse, circle or even a rectangle, for example.

[0035] As can be derived from Figure 2, the thickness (in Z-axis direction) of the foot portion 120 is in a predefined range, so that stability of the guide rail 100 is maintained. In the illustrated case, the head surface 121 is inclined with respect to a common plane defined by the lateral edges 125 (i.e., a plane defined by the Y-axis and X-axis (Figure 1)). Such inclination may be in accordance with the norm ISO 7465:2007.

[0036] As a mere example, the thickness of the foot portion 120 from a centre of the foot portion 120 to the respective lateral edge 125 is substantially the same or increases towards the lateral edge 125. For instance, the thickness can increase (from the centre of the foot portion 120 to each lateral edge 125) between 10 to 20% of a minimum thickness at the centre of the foot portion 120. Preferably, the thickness increases between 14 to 18% of the minimum thickness at the centre of the foot portion 120.

[0037] On the other hand, by forming the recess 130 material of the guide rail 100 is saved. Particularly, the recess 130 is disposed between the two lateral edges 125 and points towards the head portion 110 from the common plane. This allows omitting 15 to 20% of the material of the guide rail 100 compared to a guide rail having a plane base surface as with common guide rails, such as in accordance with the norm ISO 7465:2007.

[0038] With reference to Figures 1 and 3, a part 126 of the base surface 122 can be flattened in a longitudinal end section of the guide rail 100. With particular reference to Figure 3, a part 126 of the base surface 122 can be machined or grinded, so that it is (more) parallel to the common plane, i.e., flattened in the regions 126 of the lateral edges 125. This flattened part 126 may extend from the longitudinal end of the guide rail 100 over a predefined length L F along the longitudinal direction of the guide rail 100 (i.e., the X-axis direction). Such predefined length L F may correspond to the overlap with a counter plate 150 (Figure 4; also referred to as a fishplate).

[0039] The longitudinal end of the guide rail 100 may comprise a notch 140 in a front face of the guide rail 100. At the opposite longitudinal end of the guide rail 100 there may be a corresponding protrusion 141 (Figure 4; but not illustrated in the portion of the guide rail 100 in Figure 1), so that two guide rails 100 can be coupled to one another by inserting the protrusion 141 of one guide rail 100 into the notch 140 of the other guide rail 100.

[0040] With reference to Figures 1 and 4, the longitudinal end section of the guide rail 100 (such as the section specified by the predefined length L F ) can further comprise at least one through hole 130. Such through hole 130 allows mounting the guide rail 100 to a counter plate 150 (comprising a corresponding through hole). Due to the flattened part 126 at the base surface 122, the contact between the guide rail 100 and the counter plate 150 can be improved.

[0041] The through hole 130 in the foot portion 120 can be surrounded by a partial bore 131. The partial bore 131 can be considered as flattening a portion of the head surface 121. As a mere example, the bore 131 facilitates receiving a nut or washer when mounting the guide rail 100 to the counter plate 150.

[0042] Figure 4 further schematically illustrates a mounting clip 160 that allows mounting the guide rail 100 to a structure (not illustrated), for example, in a building. Such mounting clip 160 can be a common clip partially overlapping the foot portion 120 and contacting the head surface 121.

[0043] The cross-section of the guide rail 100 can be axially symmetric. For instance, a centre axis along the vertical direction (Z-axis direction) through the head portion 110 can form the axis of symmetry A S .

[0044] It is believed that the advantages of the technique presented herein will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, constructions and arrangement of the exemplary aspects thereof without departing from the scope of the disclosure or without sacrificing all of its advantageous effects. Because the technique presented herein can be varied in many ways, it will be recognized that the disclosure should be limited only by the scope of the claims that follow.

Claims

1. A guide rail (100) for an elevator, wherein the guide rail, in a cross-section thereof, comprises: a head portion (110); and a foot portion (120) comprising a head surface (121) substantially facing the head portion (110) and a base surface (122) arranged opposite to the head surface, characterised in that the foot portion (120) has a recess (130) at the base surface.

2. The guide rail (100) of claim 1, wherein the recess (130), in the cross-section, has a shape of a Gaussian distribution or parabola or a shape of a portion of a triangle, rectangle, circle or ellipse.

3. The guide rail (100) of claim 1 or 2, wherein the foot portion (120) extends in two lateral directions with respect to the head portion (110) and forms two lateral edges (125), and wherein the recess (130) is disposed between the two lateral edges (125).

4. The guide rail (100) of claim 3, wherein a thickness of the foot portion (120) from a centre of the foot portion (120) to the respective lateral edge (125) is substantially the same or increases towards the lateral edge (125), preferably increases between 10 to 20% of a minimum thickness at the centre of the foot portion, and more preferably increases between 14 to 18% of the minimum thickness at the centre of the foot portion.

5. The guide rail (100) of one of claims 1 to 4, wherein the cross-section of the guide rail (100) is axially symmetric.

6. The guide rail (100) of one of claims 1 to 5, wherein, in a longitudinal end section of the guide rail (100), a part (126) of the base surface (122) is flattened.

7. The guide rail (100) of claim 6, further comprising: at least one through hole (130) through the foot portion (120) in the longitudinal end section of the guide rail (100), wherein, preferably, the through hole is surrounded by a partial bore (131) flattening the head surface (121).

8. The guide rail (100) of one of claims 1 to 7, further comprising: a notch (140) in a front face of the guide rail (100), and / or a protrusion (141) in a front face of the guide rail (100), and / or an intermediate section (115) between the head portion (110) and the foot portion (120), and / or a tread (112) formed at least at lateral surfaces of the head portion (110).

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