SUBJECT MATTER OF THE INVENTION

The subject matter of the present invention is, as established in the invention title, a tensioner system for a lift without a counter-weight, which is intended to ensure tension in the lower strand when faced with elongation brought about in the suspension system of the lift without a counter-weight.

The present invention is characterised by the fact that it is a basic lever system actuated by gravity, eliminating the need for any sort of auxil iary actuation system, be it mechanical, hydraulic, electrical or similar. Thus, it ach ieves an equ il ibrium between momenta, by balancing out the force generated by the load of the tensioner with the defined and necessary tension in the lower strand of the suspension system.

Therefore, the present invention falls within the field of lifts without a counter-weight, and in particular, among those having means to balance the tension in the lower strand of the suspension system.

BACKGROUND OF THE INVENTION

In the state of the art, there are several known tensioner systems for lifts without a cou nter-weight, such as those disclosed in the patents: U S2006225965 , WO 2004067429 , E S 2326023 , WO201 00591 67 , WO2008000886, which disclose various tensioning systems for drive belts of lifts without counter-weights, which in most cases are based on the use of a lever.

All of the systems known in the state of the art have features that could be improved:

- In some cases it is necessary to employ electrical tensioning means, as in the case of patent WO2008000886, wh ich employs an actuator (electric motor) that turns the second deflection sheave (figure 4).

- They are based on auxiliary mechanical (through the action of a spring), hydraulic, electrical or other such systems.

- They take up space, either in the floor area or in the space at the bottom of the pit.

- They are systems that do not ensure that the assembly of weights moves vertically, and do not keep the sockets in parallel with the suspension.

As such, the object of the present invention is to develop a tensioner system for a lift without a counter-weight that overcomes the aforementioned drawbacks, developing a tensioner system that is actuated by gravity alone, without the need for additional actuation means, that occupies a minimal amount of space, that ensures the weights move vertically and keeps the sockets in parallel with the suspension, developing a tensioner system such as that which is described below, and whose essential nature is expressed in the first claim.

DESCRIPTION OF THE INVENTION

The subject matter of the present invention is a tensioner system for a lift without a counter-weight, which is intended to ensure tension in the lower strand of the lift.

In figure 1 , one may observe a schematic representation of a lift without a counter-weight. The lift is made up of a lower strand (6) and an upper strand (4). The upper strand (4) suspends the car (2) and its length is variable, due to the movement of the lift. The lower strand (6) is guided by the lower portion of the car (2) from the machine (3) to the tensioner system (1 ), and tensed by said system. Said lower strand (6) collects and returns the belt to the upper strand (4) as the car (2) moves up and down, such that the position of the belt is kept constant both at the belt socket end and at the socket tensioner end, except in possible instances of elongation of the belt, thus eliminating the need for a mobile counter-weight in the shaft.

The tensioner system object of the invention is a lever system actuated by gravity, eliminating the need to use mechanical, hydraulic, or other such means. The system balances out the force generated by the load of the tensioner with the defined and necessary tension in the lower strand of the suspension system.

The tensioner system is a lever system actuated by gravity, and is formed by:

- A tensioner support assembly forming a first articulated quadrilateral, and which is joined at one of its ends to a belt socket assembly forming a second articulated quadrilateral.

Wherein the tensioner support assembly forming the first articulated quadrilateral comprises:

^■ a support plate that is joined to a fixed element, such as the guide, the shaft wall, the floor, etc.,

^■ two lever arms that are joined by a hinge with a pivot point to the support plate,

^■ a weight support assembly, and

^■ a tensioner arm,

where said lever arms are joined to the weight support assembly and to the tensioner arm.

The belt socket assembly, responsible for fastening the end of the lower strand opposite the mach ine, and wh ich forms the second articulated quadrilateral, and is joined to the lower end of the tensioner arm.

The lever arms define the lever ratio. They are joined with a pivot point to the support plate.

The tensioner su pport assembly that forms the first articu lated quadrilateral acts on the leverage principle, where the joint between the tensioner arms and the support plate constitutes a fixed point. The weight support assembly and the tensioner arm are fastened to the lever arms by a hinge, thus forming either a type 1 or a type 2 lever.

This first articulated quadrilateral making up a basic lever system seeks to:

- Give the system redundancy by distributing the loads, resulting in greater safety in the face of possible failures.

- Create an articulated quadrilateral in combination with the tensioner arm that only allows both the weight support assembly and the tensioner arm to move vertically.

The tensioner system is equipped with a safety element with an electrical contact or limit switch that limits the useful range of the tensioner, keeping the lower strand from losing tension or being damaged due to overtension, sending the system and order to stop, should the defined useful range be reached.

Stops may be arranged upon the support plate to limit the movement of the lever arms, in order to prevent the mechanism from operating incorrectly.

The electrical contact or limit switch is activated prior to any contact that the arms might have against the stops mounted upon the support plate.

The belt socket assembly comprises a middle plate joined to the lower end of the tensioner arm of the tensioner support assembly. Two joining arms are fastened to the middle plate, the lower end of the former being joined to a terminal support.

The purpose of the belt socket is to:

1 . Keep the belt socket plate in parallel with the floor, in order to prevent load imbalances between the suspension system belts due to rotation.

2. Absorb any horizontal deviation due to the rotation of the lever arms, keeping the terminal support of the tensioner in a vertical relationship with the start base.

Among other advantages, the tensioner system ensures the traction of the belt inside the mach ine, fastens the end of the lower strand of the suspension system, absorbs any elongation of the strands, and takes up a minimal amount of space.

The first articulated quadrilateral makes it so that both the weight support assembly and the tensioner arm are only allowed to move vertically. Meanwhile, the second articulated quadrilateral ensures that the belt socket is always parallel and vertical, which also helps with load distribution and helps to absorb any horizontal deviation due to the rotation of the lever arms, keeping the terminal support of the support vertical.

The tensioner system ensures constant tension in the lower strand, absorbing any elongations of the suspension system, ensures that the belt socket is always parallel and vertical, occupying a minimal amount of space, and being actuated by gravity alone.

Throughout the description and the claims, the word "comprises" and variants thereof are not intended to exclude other technical characteristics, additions, components or steps. For those skilled in the art, other objects, advantages and characteristics of the invention may be deduced from both the description and the practical use of the invention. EXPLANATION OF THE DRAWINGS

As a complement to the present description, and for the purpose of h el p i n g to m a ke th e ch a racte ri sti cs of th e invention more readily u nderstandable, in accordance with a preferred practical exem plary embodiment thereof, said description is accompanied by a set of drawings constituting an integral part of the same, which by way of illustration and not limitation represent the following.

In figure 1 , one may observe a schematic representation of a lift without a counter-weight.

Figure 2 shows a complete view of the tensioner system, object of the invention.

Figure 3 shows the tensioner support assembly.

Figure 4 shows the weight support assembly.

Figure 5 shows the belt socket assembly. PREFERRED EMBODIMENT OF THE INVENTION

With reference to the figures, a preferred embodiment of the invention proposed is described below.

In figure 2 one may observe that the tensioner system (1 ) for a lift without a counter-weight is characterised in that it comprises:

- A tensioner support assembly (8) forming a first articulated quadrilateral, and which is joined at one of its ends to

- A belt socket assembly (9) forming a second articulated quadrilateral. Where:

- the tensioner su pport assembly (8) form ing the first articulated quadrilateral comprises:

^■ a support plate (1 0) that is joined to a fixed element, such as a guide, the shaft wall or the floor,

^■ two lever arms (1 1 ) that are joined by a hinge with a pivot point to the support plate (10),

■ a weight support assembly (12), and

^■ a tensioner arm (13),

where said lever arms (1 1 ) are joined to the weight support assembly

(12) and to the tensioner arm (13),

- the belt socket assembly (9), responsible for fastening the end of the lower strand opposite the mach ine, and wh ich forms the second articulated quadrilateral, is joined to the lower end of the tensioner arm

(13) of the tensioner support assembly (8).

Figure 2 shows a type 1 lever, as the support plate (1 0) is arranged between the tensioner arm (13) and the weight support assembly (2), although it may be attached to one of the ends of the articulated quadrilateral, forming a type 2 lever.

Figure 3 shows the tensioner support assembly (8) in greater detail, wherein it is worth highlighting the hinged joining of the support plate (10) to the lever arms (1 1 ) through the hinge joints (14), such that the support plate (10) is fastened to a fixed element such as the guide, shaft wall, or similar. Thus, while the joint between the lever arms (1 1 ) and the support plate (10) only allows the lever arms (1 1 ) to turn, without moving anywhere, the tensioner arm (13) and the weight support assembly (12) may also move vertically.

The tensioner system is equipped with a safety element based on an electrical contact or limit switch (18), such that if the tensioner reaches the end of its range, whereby the lower strand may become slack, the limit switch will detect it and send the system the order to stop. If, on the contrary, the tensioner should reach the opposite end, whereby the suspension system could be damaged due to overtension, the limit switch (18) will likewise detect it and send the system the order to stop.

In addition, means acting as a kind of stop (10.1 ) may be mounted upon the support plate (10) for the purpose of limiting the movement of the lever arms, in order to prevent the mechanism from operating incorrectly.

The l imit switch (1 8), in either of its two directions, carries out this detection prior to contact with the stops (1 0.1 ) that the support plate (10) is equipped with.

The weight support assembly shown in figure 4 is responsible for generating the actuating force of the system by means of gravity, due to the weight of the weight support together with the weights placed therein. It is joined by means of pivot points to the lever arms and provides support to the weights. It is made up of a support plate (1 2.1 ) and the weights (1 2.2) themselves, fastened to the support plate (12.1 ).

Lastly, figure 5 shows the belt socket assembly (9) of the tensioner, which comprises a middle plate (15) joined to the lower end of the tensioner arm (13), and joining arms (16) joined to the middle plate (15) by their upper end and to terminal supports (17) by their lower end.

This belt socket assembly is able to keep the belt socket plate parallel to the floor, and to absorb any horizontal deviation due to the rotation of the lever arms, keeping the terminal support of the tensioner in a vertical relationship with the start base. Having thus adequately described the nature of the present invention, as well as how to put it into practice, it must be noted that, within its essential nature, the invention may be carried out according to other embodiments differing in detail from that set out by way of example, which the protection sought would equally cover, provided that the fundamental principle thereof is not altered, changed or modified.