The floor, walls and ceiling of an elevator car are generally made of heavy steel plates. To achieve a de- sired appearance, the plates are often coated either by painting or using plastic sheet material. Laminat- ing sheet is also used for the coating of the steel plates. The heavy structures added to the elevator car also add to the weight of the counterweight, and therefore a more powerful elevator motor is required, which leads to additional costs. The elevator car is generally mounted in a car frame supporting the car, which also increases the total weight.

To improve the operational efficiency of elevators, it is necessary to develop lighter elevator car struc- tures. Moreover, the number of parts in the car should be reduced to reduce the time and amount of work spent on assembling the car. The process of assembly of the elevator car should be developed so as to render it as easy and fast as possible in order to achieve cost savings.

The object of the invention is to disclose a new type of car structure designed to be mounted in a car frame, made of a light material and allowing fast as- sembly.

As for the features characteristic of the structure of the invention, reference is made to the characteriza-

tion part of claim 1. As for the features characteris- tic of the method of the invention, reference is made to the characterization part of claim 12.

The walls of the elevator car structure of the inven- tion are preferably connected to each other using a profiled corner fillet made of a single piece of mate- rial, such as e. g. steel. The profiled corner fillet also provides the advantage that, due to its struc- ture, it secures the walls to the corner of the eleva- tor car structure without any fastening elements. The profiled corner fillet comprises edges parallel to the side and back walls of the elevator car and perpen- dicular to each other and to the side surfaces of the profiled corner fillet extending from them, with pro- jections extending from the side surfaces to press the walls against the edges. The profiled corner fillet preferably has edges parallel to the walls and projec- tions for pressing the walls between them. The pro- filed corner fillet comprises only one part and there- fore the fillet can be mounted in a short time. One of the most considerable advantages of the invention is a light weight of the car, which has been achieved by using e. g. plywood board coated on both sides with laminating sheet as wall material. The walls can be easily fastened to the car floor and ceiling by means of fastening elements, such as bolts, at their upper and lower edges. The ceiling and floor of the struc- ture of the invention made of a light material are preferably manufactured from low-density plywood board of e. g. Ceiba or poplar, with a thin aluminum plate glued to each side of them to reinforce the car struc- ture. Attached with both screws and glue to the under- side of the car floor are at least three profiled fil- lets, which stiffen the structure and allow the car to be secured to the car frame and make it possible to

fasten the car cable and car sill. Screwed and glued to the car ceiling are a required number of profiled fillets to stiffen the structure and to attach the ceiling to the car frame supporting the car. The upper and lower edges of the car walls are provided with separate L-shaped cover plates attached e. g. with glue to protect the walls against soiling and to stiffen the wall structure and to hide the fastening elements at the upper and lower edges of the walls. The car can be assembled in a short time e. g. by fitting the walls into the profiled corner fillets and then to the floor, whereupon the ceiling is mounted in place. In a preferred case, when the car is being assembled, it is possible to choose whether to fit one wall at a time to the profiled corner fillet or all the walls simul- taneously to the profiled corner fillets connecting them. Using the arrangement of the invention, if the car wall should be damaged, it will not be necessary to dismantle the entire wall; instead, a hole is drilled in the wall and the wall is repaired by gluing a piece of wall material the size of the hole to the wall to mend the fault. The advantages also include a short car assembly time due to the small number of parts and the fact that the car is suited for use in many applications.

In the following, the invention will be described by referring to the attached drawings, which illustrate the various parts of the elevator car structure of the invention and their attachment to each other.

-Fig. 1 presents the various parts of the elevator car structure of the invention and shows their at- tachment to each other.

-Fig. 2 presents a profiled corner fillet according to the invention, illustrating its function.

-Fig. 3 illustrates the way in which a wall in the car structure of the invention is fastened to cover plates protecting and stiffening the wall.

Fig. 1 presents an elevator car structure 1 according to the invention, comprising two side walls 2 and a back wall 16 of the car, which are made of a light ma- terial, e. g. 12 mm plywood board with e. g. a 1 mm laminating sheet glued to each side of it to strengthen the structure. The walls 2 and 16 are se- cured to the ceiling 4 and floor 5 using fastening elements 7, such as bolts. The upper 13 and lower edges 14 of the walls are provided with a required number of fastening elements 7 to maintain a suffi- cient structural strength. At least four fastening elements 7 are needed for each wall. The fastening elements 7 of the walls 2 and 16 go through holes and notches provided in the cover plates 9 at locations corresponding to the fastening elements 7. The number of holes and notches is determined by the number of fastening elements 7 used. E. g. metallic cover plates 9 glued to the upper 13 and lower 14 edges of the walls 2 and 16 increase the rigidity of the wall structure, prevent damage to the wall elements and hide the fastening elements 7 from sight. The car structure 1 also comprises profiled corner fillets 3, made of a single piece of steel e. g. 0.8 mm thick, connecting the walls 2 and 16 of the car. Due to its structure, the profiled corner fillet 3 holds the walls 2 and 16 fast without any separate attachments.

The profiled corner fillet comprises side surfaces 17, edges 11 extending from them and projections 12 to al- low the walls 2 and 16 to be fitted between the edges

and the projections. Moreover, the elevator car struc- ture 1 comprises a ceiling 4, which is a plate of light material, e. g. a 12 mm thick plywood plate, with a thin, e. g. 0.8 mm thick aluminum sheet glued to each side of it to strengthen the structure. Attached to the top side of the ceiling 4, using both glue and screws, are metallic beams 8 to reinforce the ceiling structure 4 and to allow it to be secured. In addi- tion, the elevator car structure 1 comprises a floor 5, which, to maintain a light weight of the structure, consists of light plywood board of a thickness of e. g.

19 mm, with a thin 0.8 mm aluminum sheet glued to each side of it to strengthen the structure. Attached to the underside of the floor, e. g. using both glue and screws, are a required number of metallic beams 6 which stiffen the floor structure 5 and make it possi- ble to secure the floor.

Fig. 2 illustrates the profiled corner fillet 3 of the invention, seen from the top 4 of the structure 1, which connects the walls 2 and 16 to each other at the corner of the elevator car. The profiled corner fillet 3 comprises edges 11 extending in a direction parallel to the walls 2 and 16 and perpendicular to the fillet side surfaces 17 extending from the edges. From the side surfaces 17, there extend projections 12 touching the walls. The walls 2 and 16 are tightly fitted be- tween the projections 12 and the edges and 11.

Fig. 3 presents an example of the attachment, e. g. by gluing, of L-shaped cover plates 9 to the side walls 2 to stiffen and protect them. Both the upper edge 13 and the lower edge 14 of the wall are provided with fastening elements 7, which go through holes 10 and notches 15 in the cover plates 9. The cover plates 9 hide the dead holes 18 in the walls into which the

fastening elements 7 are inserted. The cover plates are placed one over the other at the upper and lower edges of the walls so that there are two of them at the lower edge 14 and likewise at the upper edge 13.

Cover plates 9 are mounted in the same way on the back wall 16 as well.

The assembly of the elevator car of the invention can be performed in various ways. Moreover, the profiled corner fillet may be manufactured e. g. either by ex- truding or by bending. Profiled corner fillets are also used at the corners of the wall opposite to the back wall, i. e. the wall comprising the door of the elevator car. The wall material used may also be some other corresponding light material than the material mentioned in the above description.

It is obvious to the person skilled in the art that different embodiments of the invention are not re- stricted to the examples described above, but that they can be varied within the scope of the following claims.