WO2022175992A1

WO2022175992A1 - Emergency brake

Info

Publication number: WO2022175992A1
Application number: PCT/IT2021/050320
Authority: WO
Inventors: Gabriele NIGRO
Original assignee: Mpn Srl
Current assignee: Mpn Srl
Priority date: 2021-02-19
Filing date: 2021-10-06
Publication date: 2022-08-25
Anticipated expiration: 2023-08-19
Also published as: IT202100003905A1

Abstract

A mechanical speed limiter between mobile means and guide means is described consisting of a speed detection mechanism (100) by means of a rotating wheel (200) in contact with the rail (300), comprising at least one oscillating mass (1) on a rotating flange (21) integral with a shaft (2) so that the oscillating mass (1) is subjected to the action of centrifugal force, elastic means (8) associated with the oscillating mass (1) and the rotating flange (21), a disc (4) arranged externally and mounted around the shaft (2) provided with at least one stop (3) with which a free end of the oscillating mass (1) comes into contact when the centrifugal force generated on the oscillating mass (1) overcomes the elastic force of the elastic means (8) establishing the integral rotation of the disc (4) and the shaft (2). The speed sensing mechanism (100) is connected to the hub (13) via a rotating wheel brake device (200).

Description

EMERGENCY BRAKE

The present invention relates to a mechanical speed limiter between mobile means and guide means.

In general, the present invention relates to mechanical speed limiters. In particular, the present invention relates to braking or catching devices which operate between mobile means, cages or caissons and fixed guiding elements or surfaces in a compartment or well adapted to apply friction slowing forces. The state of the art is represented by EP-B1-

1 149 041 concerning a speed limiting regulator or device for controlling or braking the movement of a stair-lift trolley in the event that some failure or malfunction in the drive mechanism, dragging the trolley along a guide of the stair-lift, allows the trolley to exceed a predetermined maximum speed, typically the stair-lift incorporates a drive motor in the trolley, the output of which engages a rack, which extends along the rail, by means of a gearbox. However, if there is a gearbox or engine failure, the carriage can be allowed to slide along the inclined rail in an uncontrolled manner. A controller for regulating the speed of a stair-lift trolley along a stair-lift track, the trolley moves along a stair-lift track in two directions, the controller includes a movable braking element in contact with the stair-lift rail, operable operating means, when the speed of the carriage along the rail exceeds a predetermined maximum value, in order to cause the braking member to engage the rail, the actuation means comprise a first rotating guide plane with the movement of the carriage along the rail and a roller operatively connected to the braking member, in sliding contact with the first guiding surface when the speed of the carriage is lower than the predetermined maximum value, in which the actuation means can be operated in the event of excessive speed in both two directions, the operating means are constructed and arranged to cause the roller to leave the first guiding surface under the influence of a centrifugally induced force.

Furthermore, the state of the art is represented by the patent EP-B1-2 687 474 concerning a detector mechanism that can be mounted on a pulley or on the cabin of an elevator, comprising a wheel which rotates according to the speed of the car and rotating arms which tilt due to the centrifugal force induced by the rotation of the wheel, magnetic means which are associated with the rotating arms generate an attraction force which maintains the position of the rotating arms until the centrifugal force exceeds the attraction of the magnetic means, an element limit switch which is part of a piece external to the wheel and against which the arm pin comes into contact when the centrifugal force generated on the arm as a result of the overspeed of the lift car exceeds the force of attraction of the magnetic medium, starting when the cab is braking.

The state of the art has highlighted solutions aimed at braking a mobile vehicle on rail by means of a brake acting directly on the rail.

A problem represented by the use of braking elements acting on the rail is the generation of high braking forces necessary to stop the moving vehicle.

The solution to the problem is represented by a system in which the braking actions are reduced through a torque reduction at multiplied speed. A further solution to the problem is represented by the use of an orthogonal braking system, that is, with the direction of the braking torque acting on a plane orthogonal to that of the rail.

The aforesaid and other objects and advantages of the invention, as will emerge from the following description, are achieved with a mechanical speed limiter between mobile means and guide means such as that described in claim 1. Preferred embodiments and non-trivial variants of the present invention form the subject of the dependent claims.

It is understood that all the attached claims form an integral part of the present description. It will be immediately obvious that innumerable variations and modifications (for example relating to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what is described without departing from the scope of the invention as appears from the attached claims.

The present invention will be better described by some preferred embodiments, provided by way of non-limiting example, with reference to the attached drawings, in which: FIG. 1 shows a front view of a portion of an embodiment of the mechanical speed limiter between mobile means and guide means according to the present invention; FIG. 2 shows an axonometric view of an embodiment of the mechanical speed limiter between mobile means and guide means according to the present invention;

FIG. 3 shows an axonometric view of a portion of an embodiment of the mechanical speed limiter between mobile means and guide means according to the present invention;

FIG. 4 shows a further front view of a portion of an embodiment of the mechanical speed limiter between mobile means and guide means according to the present invention; and

FIG. 5 shows an exploded axonometric view of a portion of an embodiment of the mechanical speed limiter between mobile means and guide means according to the present invention.

With reference to the figures, it is possible to note that a mechanical speed limiter operating between movable means and guide means for applying forces to slow down the friction is of the type placed on board a carriage sliding in two directions along a rail.

A mechanical speed limiter operating between mobile means and guide means is constituted by a speed detection mechanism 100 by means of a rotating wheel 200 in contact with the rail 300.

The speed detection mechanism 100 comprises at least one oscillating mass 1 via a pin 10 mounted on a rotating flange 21.

The rotating flange 21 is integral with a shaft 2 so that the oscillating mass 1 is subjected to the action of the centrifugal force caused by the rotation of the shaft 2.

The shaft 2 is connected to a hub 13 fixed to a base flange 14. Elastic means 8 are associated with the oscillating mass 1 and with the rotating flange 21.

A disc 4 arranged externally and mounted around the shaft 2 is provided with at least one stop 3 with which a free end of the oscillating mass 1 comes into contact when the centrifugal force generated on the oscillating mass 1 through the rotation of the shaft 2 exceeds the elastic force of the elastic means 8 establishing the integral rotation of the disc 4 and shaft 2.

Advantageously, the speed detection mechanism 100 is connected to the hub 13 by means of a braking device of the rotating wheel 200.

The braking device of the rotating wheel 200 comprises a pair of lining rings 6 in contact with the upper and lower faces of the hub 13.

A further disk 5 in contact with a ring of the pair of lining rings 6 is connected to the disk 4 by means of connection 11.

The connection means 11 are equipped with elastic means 7 to be able to establish a desired preload along the axis of the shaft 2 to be able to brake the rotating wheel 200.

The connecting means 11 are cylindrical pins with a hexagonal head. The elastic means 7 are cup or helical springs.

The surfaces of the disk 4 and of the further disk 5 are ground by turning after an electro- galvanizing process to make the supporting surfaces perfectly flat.

The stops 3 made with numerical control machines have a section that fits perfectly with the surfaces present in the centrifugal weights 1.

The retainers 3 are coupled to the disc 4 by means of a MIG welding process. At the top of the stops 3 there is a threaded hole which allows to assemble a connecting plate 9 necessary to distribute the forces due to the braking torque on several stops. The rotating wheel 200 is a pinion meshing with a rack integral with the rail 300.

The mechanical speed limiter or mechanical speed limiter or parachute device object of the present invention is mainly used to stop the uncontrolled stroke of lifting machines, elevators, electric scaffolding, cable machines, which use the rack and pinion system as a mechanism. The device can also be used in line with the axis of a cable drum and therefore in rope lifting machines. The sectors of use concern the industrial as well as civil constructions.

Compared to very bulky and heavy known devices, the mechanical speed limiter or parachute device object of the present invention is a disc brake, very versatile and reproducible in scale, to increase the braking torque it is sufficient to increase the number of springs, the diameter of the friction discs, or increase the value of the technical characteristics of the springs.

The mechanical speed limiter or parachute device that can be calibrated both in the intervention speed and in its progressivity must not stop too abruptly to prevent breakage of the gears and mainly to maintain a certain comfort in the event of the presence of people on board.

The device has centrifugal weights (1) held by suitably calibrated springs (8) un-deformed until the engagement speed is reached, the centrifugal weights connected to an axis (2) by means of cylindrical pins in hardened and ground steel (10). The axis rotated by the pinion or the drum to which it is connected generates the centrifugal force of the centrifugal masses (1) which, by rotating on the details (10), engage with respect to the stops (3), the rotation of the axis involves the discs upper and lower discs (4), (5) which begin to friction on the brake linings (6) generating the braking torque, the upper and lower discs (4), (5) are pressed with respect to the brake linings (6) by means of the closing springs (7), the preload and the elasticity characteristics K of these springs determine the braking force of the device.

The device can be completely dismantled for maintenance and replacement of parts subject to wear. The hub (13) is coupled to the base flange

(14) by means of six cylindrical pins with recessed hexagon, to allow the extraction of the lower disc (5) and of the brake linings (6). The surfaces of the discs 4 and 5 are ground by turning after the electro-galvanizing process to make the supporting surfaces perfectly flat.

The stops (3) made with numerical control machines have a section that fits perfectly with the surfaces present in the centrifugal weights (1), the stops (3) are coupled to the upper disc (4) by means of a MIG welding process, at the top of the stops (3) there is a threaded hole that allows you to assemble a connecting plate (9) necessary to distribute the forces due to the braking torque over several stops.

The mechanical speed limiter or parachute device makes it possible to progressively stop the vertical fall of a climbing system operated by a rack and pinion mechanism.

The mechanical speed limiter or parachute device consists of a transmission shaft driven by a pinion directly integral with the rack imparting the motion.

The mechanical speed limiter or parachute device is equipped with a centrifugal mechanism that causes it to engage when the descent speed is exceeded. The intervention of the device involves deceleration of less than 10 meters per second squared, the stopping space is variable according to the rated speed and the load, in any case it is less than 0.5 meters.

The mechanical speed limiter or parachute device must be installed on a plate with a minimum thickness of 6 mm mm for a first model and 10 mm for the remaining models, the centering seat has a diameter of 80-125-130 mm, the brake of the first model is equipped with three holes of 10 mm in diameter placed at 120°. The mechanical speed limiter or parachute device is positioned in the centering hole by having three threaded pins with self-locking nuts tightened to a torque of 60 Newton x meter. The mechanical speed limiter or parachute device of models subsequent to the first has four threaded holes of diameter 12 in which four pins are tightened with a torque of 80 Newton x meter, possibly with four. It is advisable to use four locknuts to prevent any tightening losses. There is also a further model of mechanical speed limiter or parachute device with four 14 mm holes, fixed with self-locking nuts with a tightening torque of 90 Newton x meter.

The mechanical speed limiter or parachute device is protected by electrolytic zinc plating and a removable cover for carrying out periodic maintenance checks.

The mechanical speed limiter or parachute device connected to the rack by means of pinions with a nominal diameter between 100 and 160 mm must respect a winding direction. The start-up of the emergency device is automatically restored once a short uphill run has been made.

Claims

1. Mechanical speed limiter operating between moving means and guide means to apply friction slowing forces, of the type placed on board a carriage sliding in two directions along a rail, consisting of a speed sensing mechanism (100) by means of a rotating wheel (200) in contact with the rail (300), the speed detection mechanism (100) comprising at least one oscillating mass (1) by means of a pin (10) mounted on a rotating flange (21), called flange rotating (21) integral with a shaft (2) so that said oscillating mass (1) is subjected to the action of the centrifugal force caused by the rotation of the shaft (2), said shaft (2) connected to a hub (13) fixed to a base flange (14), elastic means (8) associated with said at least one oscillating mass (1) and with the rotating flange (21), a disc (4) arranged externally and mounted around the shaft (2), said disk (4) provided with at least one stop (3) with which one end of the oscillating mass (1) comes in contact when the centrifugal force generated on the oscillating mass (1) through the rotation of the shaft (2) exceeds the elastic force of the elastic means (8) establishing the integral rotation of the disk (4) and shaft (2), said mechanical speed limiter characterized in that the speed detection mechanism (100) is connected to the hub (13) by means of a braking device of the rotating wheel (200).

2. Mechanical speed limiter according to the preceding claim, characterized in that the braking device of the rotating wheel (200) comprises a pair of brake lining rings (6) in contact with the upper and lower face of the hub (13), a further disc (5) in contact with a ring of the pair of lining rings (6), said further disk (5) connected to the disk (4) by connecting means (11).

3. Mechanical speed limiter according to the preceding claim, characterized in that said connecting means (11) are provided with elastic means (7) to be able to establish a desired preload along the axis of the shaft (2) to be able to brake the rotating wheel (200).

4. Mechanical speed limiter according to one of the preceding claims, characterized in that the connecting means (11) are cylindrical pins with a hexagonal head, and the elastic means (7) are cup or helical springs.

5. Mechanical speed limiter according to one of the preceding claims, characterized in that the surfaces of the disk (4) and of the further disk (5) are ground by turning after an electro- galvanizing process to make the supporting surfaces perfectly flat.

6. Mechanical speed limiter according to one of the preceding claims, characterized in that the stops (3) made with numerical control machines have a section that fits perfectly with the surfaces present in the centrifugal weights (1), the stops (3) being coupled to the disc (4) by means of a MIG welding process.

7. Mechanical speed limiter according to one of the preceding claims, characterized in that at the top of the stops (3) there is a threaded hole which allows to assemble a connecting plate (9) necessary to distribute the forces due to the braking torque over several stop.

8. Mechanical speed limiter according to one of the preceding claims, characterized in that the rotating wheel (200) is a pinion meshing with a rack integral with the rail (300).