DESCRIPTION TECHNICAL FIELD

The present invention refers to the field of latches for doors, hatches, and the like, of household appliances, appliances in general, and furnishings, and it relates to a braking spring device adapted to provide a controlled and/or balanced closing and/or opening force, for example, to a hinge of a bottom or top hatch having a horizontal rotation axis.

BACKGROUD ART There are known hinges for dishwasher doors having a movable member connected to an elastic spring through a transmission, e.g., a wire or cable redirected by pulleys or winches to an elastic spring, generally of the helical type and operating in extension, which transmits its own elastic force to the movable member through the wire.

When the door of the dishwasher opens, the movable member becomes positioned by pulling the wire, whereby the spring becomes elongated, and the force thereof partially compensates the weight and the corresponding opening torque of the hatch. A drawback of such springs is that they transmit an elastic force having a modulus that is proportional to the elongation of the spring itself, whereas the opening torque resulting from the weight follows a different rule. This prevents the hatch from being perfectly balanced in all positions between the opening and the closing.

Another drawback of such springs is that they cannot react in any way to forces and impulses acting on the hatch, and for example resulting from an increase in the weight of the hatch, (e.g., due to a coating), and thus requiring a calibration or replacement of the springs, or more simply, to the excessive push produced by a user during the opening.

Patent application No. EP 3 056 644 Al discloses a braking spring device comprising the features of the preamble of the claim 1 of the present document.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a braking spring device suitable for providing the hinge and the hatch with the ability to stop the latter in any intermediate position.

Another object is to provide a device suitable for balancing hatches having significantly different weights without the need for calibrating or replacing any parts thereof.

A further object is to provide a device that occupies approximately the same space as a corresponding helical spring of the known type, and that may be easily mounted in place of, or to replace, such known springs, without the need to modify the appliance on which they are mounted.

Another object is to provide a device that may be configured or modified in a simple manner to adapt it to different needs. A further object is to provide a device suitable for rapidly dampening any excessive opening impulses or speeds.

BRIEF DESCRIPTIONS OF DRAWINGS

The features of the invention are highlighted hereinafter, with specific reference to the accompanying drawings, in which: Figure 1 shows a side view of the braking spring device subject-matter of the present invention in a retracted condition, i.e., in a condition of minimum length of the respective elastic means;

Figure 2 shows a front view of the device in Figure 1 ;

- Figure 3 shows a view of the device in Figure 1 , where some hidden elements are shown in dashed lines, and in which there are shown some forces and a torque acting on/in the device;

Figure 4 shows a top view of the device in Figure 1 ;

Figure 5 shows a section view along the plane V - V of Figure 4;

- Figure 6 shows an axonometric view of the device in Figure 1 ;

Figure 7 shows an exploded view of the device in Figure 1.

BEST FORM TO CARRY OUT THE INVENTION Referring to Figures 1-7, numeral 1 denotes the braking spring device subject-matter of the present invention, comprising at least:

an elastic means 3 whose features shall be described hereinbelow;

a guide means 5 made of a box-type metal sheet and having an elongated form; a carriage means 7, for example shaped as a metal sheet or plate;

- a drag means 9 comprising a friction slide, for example in the form of a lining, or the like, supported by a metal or plastic body having a lateral profile shaped as a triangle or as an isosceles trapezium.

The carriage means 7 is provided with a connection 8 for a tie-rod, e.g. a cable or a string, or a transmission for the connection to a hatch, a door or a hinge, to transmit to the latter forces in one or possibly two opposite directions. For example, the connection transmission may be of a rigid or articulated kind, and suitable for transmitting forces in one or possibly two opposite directions. Such carriage means 7 is slidable along the guide means 5, between a retracted condition R and an extended condition, not shown, in which the guide means 5 reaches its own extreme position opposed to the retracted condition. The carriage means 7 is provided with a transversal sliding pivot 13, preferably made of steel.

The sliding pivot 13 transversally protrudes from both sides of the carriage means 7, and its ends slidably engage with respective longitudinal guide slots 15 obtained in lateral walls of the guide means 5. Such longitudinal guide slots 15 are parallel to the sliding wall 11.

In order to better guide the sliding pivot without any jamming or excessive friction, the edges of each guide slot 15 extend towards the outside of the box-type guide means, perpendicularly to the plane of the faces of the guide means 5 on which the guide slots 15 are arranged.

In order to make the sliding easier, the sliding pivot 13 may be provided with bushings or other rolling or low-friction elements.

The elastic means 3 is connected between the guide means 5 and the carriage means 7, and transmits to the latter its own elastic force directed towards the retracted condition R.

The elastic means 3 comprises a helical spring, shown in the figures, operating in extension, its ends being each connected with a corresponding hooking means 21, 23 of the carriage means 7 and of the guide means 5, respectively. The hooking means 21 of the carriage means 7 is provided at an end of the latter 7 protruding from the guide means 5 through a longitudinal slot thereof 5.

The hooking means 23 is provided or obtained at an end of the guide means 5; the geometrical straight line mutually connecting the hooking means 21, 23, and the longitudinal geometric axis of the elastic means 3 are parallel to the longitudinal extension of the sliding wall 11.

According to a simple alternative, falling within the invention and whose understanding requires no drawings, the elastic means 3 comprises a helical spring operating in compression; one of the ends of such compressed spring is rigidly connected to one of the hooking means 21, 23 and the other end is connected to the other hooking means 21, 23 by means of a spring guide, or the like.

The drag means 9 is connected with one end of the carriage means 7, and frictionally slides along a respective sliding wall 11 inside the guide means 5.

For example, the guide means 5 is made of a die-cut, bent metal sheet, and has the shape of an elongated box, and contains, at least partially, the drag means 9 and the carriage means 7.

The sliding wall 11 is perpendicular to the two lateral facing faces of the guide means 5 bearing the guide slots 15. The carriage means 7 is connected to the drag means 9 through a connection pivot 17 parallel to the sliding pivot 13. The connection provided by the connection pivot 17 is of the rotatable type, such that the sliding face of the drag means 9 is always parallel to, and in contact with, the face inside the guide means 5 of the sliding wall 11.

The connection 8 for the connection tie-rod or transmission is preferably arranged on the geometrical straight line connecting the sliding pivot 13 and the connection pivot 17, and parallel to the sliding wall 11. The line of action of the force transmitted by such tie-rod or transmission to the carriage means 7 coincides at least approximately with said connecting straight line. Hence, the force transmitted by the tie-rod or the transmission to the carriage means 7 does not produce any torque acting on the latter 7, as shown in Figure 3, where the curved arrow is the torque generated by the force of the elastic means 3, acting on the carriage means 7, and the arrow directed downwards is the reaction force acting between the drag means 9 and the sliding wall 11. In this case, shown in the Figures, the dynamic friction between the drag means 9 and the sliding wall 11 , which brakes the motion of the carriage means, is a linear function merely of the elongation of the elastic means 3. A simple alternative device, whose understanding requires no specific drawings, provides that the line of action of the force acting on the connection is parallel to the sliding wall 11 , but the connection 8 for the tie-rod or the transmission is staggered with respect to said connecting straight line on the side of the friction surface of the drag means 9 onto the sliding wall 11 , or on the opposite side to increase or decrease the torque acting on the carriage means 7, and thus to increase or decrease the friction between the drag means 9 and the respective sliding wall 11. A further simple alternative, not shown, provides that the drive means 5, or the appliance on which the device is mounted, is equipped with a bend pulley or pivot for the tie-rod or transmission for the connection to a hatch, a door or a hinge.

The position of such pulley or pivot is such that the line of action of the force acting on the connection 8 is oriented towards the sliding pivot 13, or away from the latter 13, so as to apply to the carriage means 7 a cooperating or antagonist torque as compared to the one produced by the elastic means 3.

According to an additional simple alternative, whose understanding requires no drawings, the device is provided with a damper means, preferably of the fluid type, such as viscous oil, interacting between the guide means 5 and the carriage means 7, to dampen any possible excessive speeds imparted to the latter.