The present invention pertains to a balustrade for a roof of an elevator car, an elevator car with a balustrade and to a method for assembling a balustrade.

Several balustrades for protecting maintenance/service personnel on the roof of an elevator car of an elevator system from falling down from the elevator car into the shaft are known. A car for an elevator with a balustrade is known from US 2013/0092479 Al . The balustrade comprises horizontally extending bars which connect posts with each other, wherein the post extend vertically and are fixed to the roof of the elevator car.

Typically, the bars are connected to the posts via nuts and/or bolts. Normally, one disadvantage hereof is that many parts are necessary for assembling/mounting the balustrade. Nuts and/or bolts are typically very small and can get lost while transporting and/or assembling/mounting the balustrade on the roof of the elevator car. Furthermore, generally, assembling/mounting the balustrade via nuts and/or bolts takes a very long time. Also, normally, tools are necessary for assembling the balustrade.

There may be a need for a balustrade for a roof of an elevator car which comprises few parts and which can be assembled in a short time. Also, there may be a need for an elevator car with a balustrade wherein the balustrade comprises few parts and can be assembled in a short time. Also, there may be a need for a method for assembling a balustrade which takes a short time.

Such needs may be met with the subject-matters of the independent claims. Advantageous embodiments are defined in the dependent claims and in the following specification.

According to a first aspect of the present invention, a balustrade for a roof of an elevator car is proposed comprising at least one bar which largest dimension extends horizontally along its length, and posts which largest dimension extends vertically along its length, respectively, wherein the posts are adapted to be connected to the roof of the elevator car, wherein the posts comprise receiving elements for holding and receiving end sections of the bar, wherein opposing end sections of the bar are disposed in the receiving elements of two posts for connecting the two posts with one another, wherein the bar is fixed in the receiving elements in directions perpendicular to the length of the bar by a form fit.

Typically, one advantage hereof is that the balustrade comprises few parts. Also, generally, the parts of the balustrade cannot get lost easily since the parts are not very small (e.g., the parts are not smaller than the normal size of a hand of a human).

Furthermore, typically, the balustrade can be mounted/assembled in short time. In addition, generally, the balustrade can have many different forms (e.g., box-shaped, triangular-shaped etc.). Also, typically, the balustrade can be mounted/assembled without tools.

In particular, a form fit can be a connection between elements, wherein one element meshes/engages in the other element. With other words, in particular, in a form fit one element can be in the way of the other element such that essentially no movement is possible in at least one direction.

According to a second aspect of the present invention, an elevator car with a balustrade as described above is proposed, wherein the balustrade is fixed on a roof of the elevator car. According to a third aspect of the present invention, a method for assembling a balustrade comprising at least one bar which largest dimension extends horizontally along its length and posts on a roof of an elevator car of an elevator system wherein the largest dimension of the post extends vertically along its length, respectively, is proposed, comprising the steps: positioning the bar such that the length of the bar extends horizontally, inserting opposing end sections of the bar in C-shaped receiving elements of the posts such that the bar is fixed in the receiving elements in directions perpendicular to the length of the bar by a form fit, and fixing the posts to the roof of the elevator car.

Typically, one advantage hereof is that the balustrade can be mounted/assembled from few parts. Also, generally, during the assembly, the parts of the balustrade cannot get lost easily since the parts are not very small (e.g., the parts are not smaller than the normal size of a hand of a human). Furthermore, typically, the balustrade can be

mounted/assembled in short time by this method. Also, typically, the method can be executed without tools. Typically, the vertical direction can be the direction in which the elevator car moves during operation of the elevator system. Generally, the horizontal direction runs perpendicularly to the vertical direction. Normally, the length of the bar is the direction of the largest dimension of the bar. Typically, the bar has two dimensions which are very small compared to the largest dimension of the bar. Normally, the posts have two dimensions which are very small compared to the largest dimension/length of the post.

Ideas underlying embodiments of the present invention may be interpreted as being based, inter alia, on the following observations and recognitions.

According to an embodiment, the bar is fixed in the receiving elements without screws and without bolts. Typically, this ensures that no screws and/or bolts can be lost during transporting or mounting/assembling of the balustrade. Furthermore, generally, this ensures that the balustrade can be mounted/assembled in a short time.

According to an embodiment, the receiving elements have essentially a form of the upper case letter "C", wherein an open side of the C-shaped receiving element is oriented towards the post. Typically, this allows to fix the bar on the posts in a very short time. Furthermore, generally, the balustrade can be produced for a low price.

According to an embodiment, opposing end sections of the bar are formed

complementary to the receiving elements, respectively. Normally, this allows for a very secure holding of the bar in the receiving elements.

According to an embodiment, the receiving elements are fixed to the posts by welding. Generally, this ensures a reliable and low-priced fixing of the receiving elements on the posts.

According to an embodiment, the receiving elements comprise a first receiving element and a second receiving element disposed at one of the posts in immediate vicinity to each other and essentially at the same height of the post. Typically, this lowers the time for mounting/assembling the balustrade. According to an embodiment, two end sections of two bars received in the first and second receiving elements which are disposed in immediate vicinity to each other have different forms. Generally, this saves space and allows a compact balustrade.

According to an embodiment, one first receiving element of the receiving elements has a first cavity for receiving an end section of a first bar and a second cavity for receiving a part of an end section of the second bar and one second receiving element of the receiving elements has a first cavity for receiving an end section of the second bar, wherein the end section of the first bar is disposed in the first cavity of the first receiving element and wherein the end section of the second bar is disposed in the second cavity of the first receiving element and in the first cavity of the second receiving element. Normally, by this, the end sections of the two bars can be fixed in a very small space technically easily.

According to an embodiment, the end section of the first bar which is disposed in the first cavity of the first receiving element comprises two projections framing a passage for the end section of the second bar, and wherein the second bar comprises a projection disposed in the passage of the first bar. Typically, the bars can be produced with low costs. Furthermore, generally, the bars can be interlaced technically easily which provides a very reliable fixing.

According to an embodiment, the projection of the second bar penetrates the post.

Generally, one advantage hereof is that the bars are fixed even more securely.

According to an embodiment, the posts comprise several receiving elements at different heights and several bars at different heights. Generally, this increases the safety of the balustrade for the personnel. Normally, the bars in different heights hinder the personnel in the balustrade from falling into the shaft even more reliably.

In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawing. However, neither the drawing nor the description shall be interpreted as limiting the invention. Fig. 1 shows a perspective view of an embodiment of the balustrade according to this invention;

Fig. 2 shows a perspective view of one of the posts of the balustrade of Fig. 1 ; Fig. 3 shows a detailed view of the section III of the post of Fig. 2; Fig. 4 shows a first receiving section of the post of Fig. 2; Fig. 5 shows a second receiving section of post of Fig. 2; Fig. 6 shows a bar of the balustrade of Fig. 1 ; Fig. 7 shows a first end section of the bar of Fig. 6; Fig. 8 shows a second end section of the bar of Fig. 6; Fig. 9 shows a detailed view of a section of the balustrade of Fig. 1 ; Fig. 10 shows a detailed view of a section of the balustrade of Fig. 1 without the receiving elements; and

Fig. 11 shows a further detailed view of the section of the balustrade of Fig. 1 without the receiving elements.

The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

Fig. 1 shows a perspective view of an embodiment of the balustrade 1 according to this invention. Fig. 2 shows a perspective view of one of the posts 10, 12, 14, 16 of the balustrade 1 of Fig. 1. Fig. 3 shows a detailed view of the section III of the post 10, 12, 14, 16 of Fig. 2. Fig. 4 shows a first receiving section of the post 10, 12, 14, 16 of Fig. 2 Fig. 5 shows a second receiving section of post 10, 12, 14, 16 of Fig. 2. The balustrade 1 is adapted to be installed on the roof of an elevator car of an elevator system. The balustrade 1 is for protecting maintenance/service personnel from falling down from the roof of the elevator car into the elevator shaft.

The balustrade 1 comprises four post 10, 12, 14, 16 which extend/run vertically (i.e., in the direction in which the elevator car moves during operation of the elevator system) wherein each post 10, 12, 14, 16 comprises a base 20, 22, 24, 26 for fixing the post 10, 12, 14, 16 to the roof of the elevator car. The post 10, 12, 14, 16 is an angle profile.

The balustrade 1 further comprises at least one bar 50-58, in particular several bars 50-58, which run horizontally (i.e., perpendicular to the direction in which the elevator car moves during operation of the elevator system). Each bar 50-58 connects two neighboring posts 10, 12, 14, 16. In Fig. 1, three bars 50-58 are provided at the same height, respectively, each bar 50-58 on one side of the incomplete rectangle. This way at each of the three sides of the balustrades 1 one bar 50-58 is at the very top of the post 10, 12, 14, 16, one bar 50-58 is about three fourths of the height of the post 10, 12, 14, 16 and one bar 50-58 is about one third of the height of the post 10, 12, 14, 16. The height of the post 10, 12, 14, 16 runs vertically.

The bars 50, 51, 56 at the very top of the posts 10, 12, 14, 16 can be can be handrails, respectively, adapted to be grasped by the hand so as to provide support. The post 10, 12, 14, 16 comprises two flange elements which have a degree of ca. 90° between them. Other angles, e.g., ca. 45° or ca. 120°, are possible.

Each post 10, 12, 14, 16 comprises receiving elements 30, 40 for receiving end sections 60, 62 of the bars 50-58. Three times, at different heights, two receiving elements 30, 40 are provided in immediate vicinity of each other at essentially the same height of the post 10, 12, 14, 16.

The receiving elements 30, 40 comprise first receiving elements 30 (so-called

"connectors") and second receiving elements 40 (so-called "holders"). The first receiving element 30 as well as the second receiving element 40 have essentially the form of the capital/upper case Latin letter "C". The open section/part of the letter "C" of the receiving elements 30, 40 is oriented towards the post 10, 12, 14, 16. The receiving elements 30, 40 are welded at the posts 10, 12, 14, 16. Other fixing methods are possible alternatively or additionally.

The first receiving element 30 has a first cavity 32/opening between the C-Section and the post 10, 12, 14, 16. Furthermore, the first receiving element 30 has a second cavity 34 in form of a central slit of the part of the first receiving element 30 which is oriented away from the post 10, 12, 14, 16. The second receiving element 40 has a first cavity 42/opening, in particular only one first cavity 42/opening, between the C-section and the post 10, 12, 14, 16. The first cavity 32 of the first receiving elements 30 runs in an angle of ca. 90° to the first cavity 42 of the second receiving element 40. The angle is the same as for the flanges of the post 10, 12, 14, 16. Other angles, i.e., 45° etc., are possible.

Fig. 6 shows a bar 51 of the balustrade 1 of Fig. 1. Fig. 7 shows a first end section 60 of the bar 51 of Fig. 6. Fig. 8 shows a second end section 62 of the bar 51 of Fig. 6.

The bar 51 has essentially a form of the capital Latin letter C in a cross-section perpendicular to the length of the bar 51. The two opposing ends of the letter C-part of the bar 51 are oriented towards each other, namely in a vertical direction. One first end section 60 of the bar 51 comprises a single projection 80 in the center of the bar 51. The single projection 80 projects a bit further over/than the first end section 60 of the bar 51, i.e., the first end section 60 of the bar 51 does not comprise the very tip of the bar 51/single projection 80. The second end section 62 of the bar 51 comprises the very tip of the bar 51 at this end (in Fig. 6 the left end). The second end section 62 comprises two projections 70, 72 framing a passage 75. The single projection 80 of another/second bar 51 penetrates this passage 75 if assembled/mounted.

The first receiving element 30 and the second receiving element 40 encloses about three fourths of the circumference of the bar 50-58, respectively.

The first receiving element 30 is wider than the second receiving element 40 since the second receiving element 40 partly covers the first receiving element 30. The width of the receiving elements 30, 40 runs along the length of the bars 50-58, i.e., horizontally. Fig. 9 shows a detailed view of a section of the balustrade 1 of Fig. 1. Fig. 10 shows a detailed view of a section of the balustrade 1 of Fig. 1 without the receiving elements 30, 40. Fig. 11 shows a further detailed view of the section of the balustrade 1 of Fig. 1 without the receiving elements 30, 40.

The end section 60, 62 of a first bar 50 is received/disposed in the first cavity 32 of the first receiving element 30. In particular, the second end section 62 of a first bar 50 (comprising two projections 70, 72 framing a passage 75) is received in the first receiving element 30. The first end section 60 of a second bar 51 (comprising the single projection 80 or a part thereof) is received in the second receiving element 40, fully or partly. The single projection 80 of the first end section 60 of the second bar 51 penetrates the second cavity 34 (slit) of the first receiving element 30. Here, the single projection 80 of the first end section 60 of the second bar 51 runs through the passage 75 of the second end section 62 of the first bar 50. Finally, the single projection 80 penetrates through the opening 18 of the post 10, 12, 14, 16 and protrudes out of the post 10, 12, 14, 16. It is also possible that the single projection 80 of the second bar 51 is flush with the outer surface of the post 10, 12, 14, 16.

The first bar 50 and the second bar 51 are essentially at the same height. The first bar 50 and the second bar 51 are fixed in the receiving elements 30, 40 by a form fit (also called form lock or form closure) perpendicular to its length, respectively. In particular, the bars 50, 51 cannot be moved up or down. Also possible is that the bars 50-58 are additionally fixed in the receiving elements 30, 40 by a frictional connection between the outer surface of the bar 50-58 and the inner surface of the C-formed receiving element 30, 40.

The bars 50-58 are fixed without bolts and/or nuts and/or washers and/or adhesive. In particular, the bars 50-58 can be fixed in the receiving elements 30, 40 in directions perpendicular to the length of the bar 50-58 by a form fit only. In particular, the bars 50- 58 can be fixed in the receiving elements 30, 40 by a form fit only.

As a first step for assembling the balustrade 1, the bars 50-58/the end sections 60, 62 of the bars 50-58 are inserted into the receiving elements 30, 40 of the posts 10, 12, 14, 16. Then as a next step, the posts 10, 12, 14, 16 are fixed to the roof of the elevator car. Thus, the balustrade 1 is mounted onto the roof of the elevator car in a short time and without tools or with very limited tools in a short time.

Alternatively, the posts 10, 12, 14, 16 can be semi-fixed at the roof of the car, so that the posts 10, 12, 14, 16 retain a limited movability. Then, the bars 50-58 are inserted into the receiving elements 30, 40 of the posts 10, 12, 14, 16 by using the limited

movability/tilting possibility of the posts 10, 12, 14, 16. Finally, the posts 10, 12, 14, 16/bases 20, 22, 24, 26 of the posts 10, 12, 14, 16 are fixed securely to the roof of the elevator car such that essentially no (relative) movement of the posts 10, 12, 14, 16 is possible. Now, the bars 50-58 cannot be moved out of the receiving elements 30, 40. This way, a fast assembling/mounting of the balustrade 1 is possible.

The receiving elements 30, 40, the posts 10, 12, 14, 16 and/or the bars 50-58 can comprise or be a metal or metal alloy. Alternatively, the bars 50-58 con comprise or be synthetic material.

Finally, it should be noted that the term "comprising" does not exclude other elements or steps and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.