SE1851064A1

SE1851064A1 - A mechanism for a safety device for a lift car, a safety device for protecting against unintended car movement of a lift car and a safety arrangement for a lift system

Info

Publication number: SE1851064A1
Application number: SE1851064A
Authority: SE
Inventors: Henrik Lindström
Original assignee: Alimak Group Sweden Ab
Priority date: 2018-09-07
Filing date: 2018-09-07
Publication date: 2020-03-08
Also published as: SE542493C2; WO2020050768A9; WO2020050768A1; EP3847119A4; EP3847119A1

Abstract

The present invention relates to a mechanism (20) for a safety device for lift car for preventing unintended car movement of the lift car. The mechanism comprise a brake (21) and at least one trigger element (30A,30B) which is coupled to the brake, wherein the at least one trigger element being capable of rotating around a regulator shaft of the safety device, wherein the at least one trigger element being brought into a trigger state by the brake (21) when the mechanism is activated, and in the trigger state, the at least one trigger element (30A,30B is prevented from rotating by the brake (21), wherein the at least one trigger element (30A,30B) is connected to a first drive gear (24) wherein the brake (21) comprises a rotatable brake shaft (23) provided with a second drive gear (26) which is engaged with the first drive gear (24), and the brake comprises a brake arrangement (25) adapted to be engaged with the brake shaft when the mechanism is in an active state for braking the rotation of the brake shaft, the first and second drive gear and the at least one trigger element.The present invention also relates to safety device for a lift car and a safety arrangement for a lift system for preventing unintended car movement of the lift car.

Description

Title A mechanism for a safety device for a lift car, a safety device for protecting against unintended carmovement of a lift car and a safety arrangement for a lift system TECHNlCAL FlELl) The present invention relates to the technical field of speed limiters of lifts, and in particular, to a safetydevice for a lift which protects against unintended movement of a lift car.

BACKGRÛUND ART Safety regulations require that a lift or eievator which is moved verticaiiy along a guide or rack is providedwith a safety device such as a safety catch. The safety device is designed to be activated if the lift carexceeds a predetermined speed and is arranged to catch and stop the lift car within a certain range ofmotion. Such a safety device is well known in the art and is typically provided with an over speedgovernor and a safety bralte. The over speed governor is configured to release the safety brake whenthe speed ofthe iift car exceeds a preset speed limit, in order to stop the lift car from further movement.

Safety standards furthermore require that a separate device for preventing unlntended car movement(UCNl device) of the lift car, for example due to overload, is provided on the lift car.

Such UClvl device may be actuated in order to block the lift car whenever the latter is halted at a floorlevel. l-lowever it may be costly to provide the lift car with a separate UClVl device since the UClvl devicecomprises both a brake and an activation mechanism.

SUMMARY OF THE lNVENTiON An object of the present invention is to provide a mechanism for safety device for a lift car whichprevents unintended movement of the lift car which is reliable, compact and cost effective.

Another object of the present invention is to provide a safety device for a lift car which preventsunintended movement of the lift car which is reliable, compact and cost effective.

Another object of the present invention is to provide a safety arrangement for a lift system whichprovides improved safety and control of a lift system, in particular in a multi-mast installation where aplurality of safety devices may be installed.

Additional objectives, and/or advantages that will be apparent to one skiiled in the art from the followingdescription of embodiments, are achieved, in full or at least in part, by a safety device for a lift car and asafety arrangement for a lift system as set out in the appended claims.

Preferred embodiments of the mechanism for a safety device for a lift ca r, safety device for a lift car andthe safety arrangement for a lift system are defined in appended dependent claims. ln order to realize the above-mentioned object, according to one aspect of the present invention, thepresent invention provides a mechanism for a safety device for lift car comprising a brake and at leastone trigger element which is coupled to the hrake, wherein the at least one trigger element beingcapable of rotating around a regulator shaft ofthe safety device, wherein the at least one trigger element 2 being brought into a trigger state by the brake when the mechanism is activated, and in the trigger state,the at least one trigger element is prevented from rotating by the brake, wherein the at least one triggerelement is connected to a first drive gear wherein the brake comprises a rotatabie brake shaft providedwith a second drive gear which is engaged with the first drive gear , and the brake comprises a brakearrangement adapted to be engaged with the brake shaft when the mechanism is in an active state forbraking the rotation of the brake shaft, the first and second drive gear and the at least one triggerelement.

A safety device is typically set to be released by the centrifugal regulator at a preset speed limit. in caseof exceeding the preset speed limit, the centrifugal regulator is arranged to release and engage therotationai bralte. However, such safety device cannot serve as protection against unintended carmovement of the lift car since it cannot be ensured that the lift reaches the preset speed limit beforethe movement from the landing is too large. instead a separate UClvl device is usually installed to protectagainst unintended car movement of the lift.

The mechanism for a safety device for a lift car of the present invention is particularly advantageous inthat the speed limit of the centrifugal regulator for releasing the safety device is reduced to 0 rn/s whenthe mechanism is activated. Thereby the mechanism for a safety of the present invention provides thefunction to protect against unintended car movement of the lift. When the mechanism is activated, thespeed limit for releasing the safety device is reduced to i) m/s, and any movements of the lift car triggersthe safety device to be released such that the lift car is prevented from moving further. in particularunintended car movements of the lift car can be prevented in advance of that the lift speed exceeds theoriginal preset speed limit.

Another advantage is that the mechanism can be remotely controlled and activated by a lift controlsystem. This is beneficial in that the safety device, which is a mechanical bralte, may be triggered by theelectrically controllable mechanism in different situations. Thereby several further functions can beachieved by the safety device in addition to being released only when the preset speed limit is exceeded.

Particular embodiments of the mechanism may include any of the following optional features, alone orin combination with each other: The mechanism may comprise that the at least one trigger element is mounted on a first yoi The mechanism may comprise that at least two trigger elements mounted on the first yoke having twoends. The trigger elements may be mounted diametrically opposite each other, where the triggerelements are mounted in each end of the yoi The at least one trigger element may comprise an axel bar or pin.The diameter of the first drive gear may be substantialiy larger the diameter of the second drive gear.

The brake may comprise an electrically controlled bral The mechanism may be activated by disconnection of power supply to the bralte switch. 3G 3 in order to realize the above-mentioned object, according to one aspect of the present invention, thepresent invention provides a safety device for protectlng against unintended car movement of a lift carcomprising a regulator shaft which is brought to rotate due to a coupllng to the motion of the lift car, asafety brake, a centrifugal regulator connected to the regulator shaft, said centrifugal regulator beingadapted to couple the regulator shaft to the safety brake by engaging at least one centrifugai body ofthe centrifugai regulator with-the safety brake to release the safety device when the lift car motionexceeds a preset speed limit, The safety device also comprises a mechanism comprising an additional brake and at least one triggerelement which is coupled to the additional brake, wherein the at least one trigger element being capableof rotating around a regulator shaft of the safety device, wherein the at least one trigger element beingbrought to rotate around the regulator shaft by the centrifugal regulator in a rotating state, wherein theat least one trigger element being brought into a trigger state by the additional bralte when themechanism is activated, wherein, in the trigger state, the at least one trigger element being preventedfrom rotatlng by the additional brake and the at least one trigger element being arranged to trlgger thecentrifugal regulator to release the safety device.

A safety device is typicaliy set to be released by the centrifugal regulator at a preset speed limit. ln caseof exceeding the preset speed limit, the centrifugal regulator is arranged to release and engage therotational brake. l-iowever, such safety device cannot sen/e as protection against unintended carmovement of the lift car since it cannot be ensured that the lift reaches the preset speed limit beforethe movement from the ianding is too large. instead a separate UCM device is usually installed to protectagainst unintended car movement of the lift, The safety device of the present invention is particularly advantageous in that the speed limit of thecentrifugal regulator for releasing the safety device is reduced to O m/s under certain conditions. Therebythe safety device of the present invention provides the function to protect against unintended carmovement of the lift, This effect is achieved when the mechanism of the safety device is activated. Thespeed limit for releasing the safety device then drops to O m/s, and any movements of the lift car triggersthe safety device to be released such that the lift car is prevented from moving further. in particularunintended car movements ofthe lift car can be prevented in advance ofthat the lift speed exceeds theoriginal preset speed limit. ln order to use the safety device as protection against unintended car movement of the lift car, forexample lf the lift car begins to slip away from a floor level by overload, the mechanism is activateddirectly vvhen the lift car is halted at a landing by for example a door switch, such that the mechanismacts on the centrifugal regulator to reduce the speed limit of the safety device to be released to (i m/s.

Another advantage is that the safety device can be remoteiy controlled and activated to be released bya lift control system. This is beneficiai in that the safety device, which is a mechanicai brake, may bereiiabiy activated by the electrically controilable mechanism in different situations. Thereby severalfurtherfunctions can be achieved by the safety device in addition to being released only when the presetspeed limit is exceeded. For example, a plurality of safety devices may be interconnected to operatetogether and to distribute the load over all the safety devices. 4 Furthermore, since the mechanism is integrated with the safety device, and the safety brake ofthe safetydevice is used for bralting the lift car, a very compact and cost effective safety device is accomplished.

The safety device is also very reliahle since the trigger element act directly on the centrifugal regulatorto release the safety device.

Particular emhodiments of the safety device may include any of the following optional features, aloneor in combination with each other: The safety device may further comprise that the at least one trigger element may he arranged to actuatethe centrifugal hody to engage with the safety hrake to release the safety device.

The safety device may further comprise that the mechanism further comprlses a first drive gear which issupported hy the regulator shaft and may he mounted to rotate independent of the regulator shaft.

The safety device may further comprise that the at least one trlgger element may he connected to thefirst drive gear.

The safety device may further comprise that the additional hrake comprises a second drive gear whichmay he adapted in order to mesh with the first drive gear.

The safety device may further comprlse that a rotatahle hrake shaft may he connected to the seconddrive gear.

The safety device may further comprise that a hrake arrangement may he adapted to he engaged withthe hrake shaft when the mechanism is in an active state in order to brake the rotation of the first drivegear and the rotation ofthe at least one trigger element.

The safety device may further comprise that the at least one trigger element and the first and seconddrive gears and the hrake shaft may he adapted to he rotated hy the centrifugal regulator when themechanism is in an inactive state.

The safety device may further comprise that the additional hrake may comprise an electrically controlledhrake, and the mechanism may he activated hy dlsconnection of power supply to the additional hrake.

The safety device may further comprise that the centrifugal regulator may comprise a first and a secondcentrifugal hody which may he connected by means ofjournals to a first yoke attached to the regulatorshaft.

The safety device may further comprise that said first and a second centrifugal body may he configuredto rotate on respective journais.

The safety device may further comprise that the mechanism may comprise a first and a second triggerelement which may he mounted diametrically opposite each other on a respective end of a second yokeconnected to the first drive gear.

The safety device may further comprise that the said second yoke may he mounted to he rotated aroundthe regulator shaft, 1G 3G 5 The safety device may further comprise that the at least one trigger element may comprise an axel or apin, and the at least one trigger element may have a iongitudinal axis which is parallei to the regulatorshaft.

The safety device may further comprise that the diameter of the first drive gear may be substantialiylarger the diameter of the second drive gear.

The safety device may further comprise that the mechanism may be adapted to be remotely activatedby a control system.

The safety device may further comprise that the centrifugal regulator may comprise a hub which isconnected to the shaft to rotate together with the shaft.

The safety device may further comprise that the hub may be fixedly connected to the regulator shaft bya wedge and groove connection in order to lock the hub to the regulator shaft.

The safety device may further comprise that the regulator shaft may be provided with helicai runningspiines.

The safety device may further comprise that a hub of the centrifugal regulator may be provided withthreads to enable an axial translation of the centrifugal regulator along the regulator shaft.

The safety device may further comprise that the first and second trigger elements may be arranged toextend into the centrifugal regulator, to enable interaction with the first and second centrifugal bodies.

The safety device may further comprise that the centrifugal regulator may be adapted to accommodatethe first and second trigger elements in a first and a second space limited by the first end of one of thecentrifugal bodies and a cam surface of the other centrifugal body and a curved guide surface on thehub.

The safety device may further comprise that the first and second trigger elements may be arranged tobe guided by the curved guide surface to rotate around the regulator shaft in the rotating state.

The safety device may further comprise that the first and second centrifugal body may be provided withone respective cam surface which may be adapted to form a nip with one respective guide surface.

The safety device may further comprise that the first and second trigger elements may interact with therespective cam surface in said respective nip to force the first and second centrifugal bodies to rotateoutwards to engage with the safety brake.

According to another aspects of the present invention, the present invention further provides a safetyarrangement for a lift system comprising at least one safety device as described above, a power supplyadapted to supply power to the safety arrangement, at least one door switch associated with a landingfor the lift car, wherein the at least one safety device is further provided with a brake switch connectedto the additional brake of the mechanism associated with the at least one safety device, the at least onebral 1G šf) 6 The safety arrangement provides the corresponding advantages as the safety device. By electricallycoupllng the brake switch of the mechanism to a door switch of the landing, the mechanism may beactivated directly when the lift car halts at the floor plane to reduce the speed limit to release the safetydevice to 0 m/s, therehy ensuring that unintended car movement of the lift car is prevented for exampleby overload.

Particular embodiments may include any ofthe following optional features, alone or in combination witheach other: The safety arrangement for a lift system may comprise that the at least one safety device is furtherprovided with a safety device switch which is adapted to be opened if the safety device has beenreleased. The at least one safety device switch may be electrically coupled to the at least one brakeswitch, and the at least one safety device switch may be adapted to disconnect the hrake switch fromthe power supply when the safety device switch is opened.

The safety arrangement for a lift system may further comprise at least one first safety device and asecond safety device. The first safety device may be provided with a first safety device switch and a firstbrake switch which may be electrically coupled to each other. The second safety device may be providedwith a second safety device switch and a second brake switch which may be electrically coupled to eachother. The first safety device switch may be adapted to be opened in response to a releasing action ofthe first safety device. The second safety device switch may be adapted to be opened in response to areleaslng action of the second safety device. The first safety device switch and said second safety deviceswitch may be electrically coupled in series. The power supply to the first brake switch and to the secondbrake switch may be disconnected when the first safety device switch or the second safety device switchare opened.

The safety arrangement for a lift system is advantageous in that several safety devices in a multi-mastinstallation may be interconnected. By electrically connecting the safety device switches in series, it canbe ensured that that all of the safety devices in the series are activated as soon as one of the safetydevices is activated by respective mechanism. The speed limit for release of any unactuated safetydevices will thus drop to 0 m/s, which means that the safety devices will be activated by any continuedmotion. Several safety devices may thus be used safely on one and the same lift. lvloreover, improvedload share between the safety devices can also be achieved.

BREEF DESCREPTlON OF THE DRAWENGS The lnvention is now described, by way of example, with reference to the accompanying drawings, inwhich: FlG. 1 illustrates a view of a safety device provided with a mechanism according to a first example of thepresent lnvention;FlG. 2 illustrates a sectional view along the line ll-ll in Figi, FlG. 3 illustrates a view of a mechanism according to one example of the present lnvention; 1G 2G 7FlG. 4 illustrates an expanded view of a safety device and a mechanism according to one example of thepresent invention, FlG. 5 illustrates an expanded view of a safety device and a mechanism according to one example ofthepresent invention, FIG. 6A illustrates a sectional view of the mechanism and the safety device, in a rotating state of themechanism, FlG. GB illustrates a sectional view of the mechanism and the safety device, in a trigger state of themechanism, FlG. 7 illustrates a view of a safety device and a mechanism according to one example of the presentinvention, FlG. 8A illustrates a schematic circuit diagram of a safety arrangement according to one example of theinvention, FiG. SB iilustrates a schematic circuit diagram of a safety arrangement according to another example ofthe invention.

Similar numbers in the drawings are used for representing similar components.

The following specific examples and drawings are merely used for exempiarily describing the technicalsolution of the present invention, and shall not be considered as all of the present invention orconsidered as a restriction or limitation to the technical solution of the present invention.

DETAELEB üESCRiPTlGN GF EXAMPLES GF TilE lNVENTiÛNExamples of the present invention will be described with reference to FIG. 1 to FiG. 8.

Firstly, reference is made to FlG. 1, which iliustrate a safety device for protecting against unintended carmovement of a lift car according to one example of the present invention. The safety device is designedfor use with a rack-mounted lift, but the invention as such is of course not limited thereto but is usefulin any known lift where a lift car is moved vertically along a guide or rack. The safety device 1 comprisesa safety device housing 2 which encloses a safety brake and a centrifugal regulator 3, and a regulatorshaft 4 which is coupled to the lift car via a coupling 5 such that the shaft rotates due to movement ofthe lift car (not shown) . ln this example, said coupling 5 comprises a gear wheel intended to engage arack (not shown).

Pig. 1 illustrates a safety brake 1 which comprises a first and a second brake member 6,8 with opposingfriction surfaces 49,41, in which said first brake member 6 can move towards the second brake member8, wherein said first brake member being rotatable with the regulator shaft 4 and in a normal state ofoperation is disengaged from said shaft, in which said first braking member can move towards thesecond brake. The first 6 and a second bralte member 8 consisting of an inner and outer concentric partrespectively. The regulator shaft 4 extends concentrically through the aggregate formed by the twobrake members, in which the first brake member 6 is surrounded by the second bralte member 8, Thefirst brake member 6 is configured as an inner drum with an end wall having a central journal with abore, through which the regulator shaft 4 extends. The friction surfaces 40,41 of the two bra l 3G 8 6, 8 are conical portions and are equipped with friction belts for effective hraking when axially engagedby the braking parts.

The first brake member 6 forms a so-called rotor for the brake and is rotatable and axially displaceablemounted for movement towards and from the second bralte member 8. Furthermore, the first brakemember 6 has an inner surface 6A directed towards the regulator shaft 4. The second braking part 8forms a so-called stator for the brake in which it is locked against rotation.

As shown in Fig. 1 the regulator shaft 4 ofthe centrifugal regulator 3 extends from the coupling 5 throughan opening 43 in the center ofa first end wall 2A and after passing the safety brake further into a circularrecess in an opposed second end wall ZB. These two end walls 2A, 25 form a respective end portion ofthe safety device housing 2 and in which end portions a respective end of the regulator shaft 4 isrotatable mounted.

The end of the regulator shaft 4 facing away from the coupling 5 has a substantially reduced diameterand passes after a shoulder end 4c into an open end forming a cyllndrical outer surface 44. At theshoulder end 4c, the regulator shaft supports a first drive gear 24 which is part of a mechanism 20(further described below).

A ball bearing is mounted on the shaft end and fitting into a corresponding seat in the second end wallZB of the housing 2.

The housing of the safety device further encloses a spring washer package 45 that surrounds the shaftand acts between a contact surface 46 of the housing at the inner end of the axle journal and a contactsurface 47 close to the free end of the axle journal.

This spring washer package 45 is adapted to exert upon the rotary brake member 6 an axiaily acting forcefor moving the brake member to engagement with the stationary brake member 8 upon activation ofthe safety device. ln this way, the brake member 6 is caused to accompany the rotation of the regulatorshaft, which results in a sheath that accornpanies the rotation being caused to be displaced along theaxle journal in a direction that leads to a reduction in the distance between the contact surfaces 46,47.The spring washer package 45 is in this way gradually placed under tension and the rotatable first brakemember is pressed ever harder against the fixed second brake member.

As illustrated in Fig 1, the centrifugal regulator 3 comprises a hub 14 which is connected to the shaft 4to rotate together with the shaft. The hub may be fixedly connected to the regulator shaft as can be seenin Fig. 5 wherein a wedge and groove connection 50 connects and locks the hub to the regulator shaft 4.Alternatively, as illustrated in Fig. 4 the regulator shaft 4 may be provided with helical running spllnes 14that engage with corresponding threads 14A provided on the hub to in addition to provide a connectionthat enables the hub to rotate with the regulator shaft also enable axial translation along the regulatorshaft ofthe centrifugal regulator.

With reference to Fig.2 and Fig. êA-SB, the centrifugal regulator further comprises two centrifugal bodies3A,3B which can engage with projections SB arranged on the inner surface of the rotatable first brakemember 6. The centrifugal bodies 3A,3B are supported by a support member which is formed as a firstyoke 9 connected to the hub 14 and extends diametrically to the regulator shaft 4. At the ends, said firstyoke supports the two centrlfugal bodies 314,38 by means of jïournals 7A,7B. Each centrifugal body is 1G 3G 9 configured to pivot, rotate on the respective journal 7A,7B , the centre of rotation for each centrifugalbody.

Each centrifugal body 3A,3B constitutes a how-Shaped rockable arm with a first end 3A.1 38.1 mountedon the respective journal on the first yoke connected to the regulator shaft, and having a second end3A.2,38.2, oppositely directed, as seen in the direction of rotation.

The bow-shaped rockable arm has an inner side surface facing the regulator shaft and an arc-shapedouter side facing the inner surface of the rotatable first brake member. A connecting portion connectsthe inner and outer side surface. The connecting portion comprises an engagement surface intended toengage with the projectlons 58 and cam surface 3A3 38.3 intended to cooperate with a trigger elementof a mechanism, further described below.

With reference to FIG. 88 illustrating a trigger state, it is shown that in response to rotation of theregulator shaft 4, said centrifugal bodies are rotated outwards to engage with abutment surfaces of theprojections 68 thereby initating a braking action of the safety device.

As iilustrated in Fig 2, the centrifugal regulator further comprises a spring 18 which is used to hold thecentrifugai bodies 3A,3B in an inner position, as seen in the radial direction. The centrifugal regulatorcomprises an L-shaped bracket 17 connected to the first yol The spring 18 is attached between the bracket and the first end 3A.1 of one centrifugal body 3A to keepthe centrifugal bodies in an inner position, as seen in the radial direction. The spring 18 is selected andadapted to apply a predetermined spring force to the centrifugai body. The spring force is based on thepreset speed limit for release of the safety device. in response to an increasing speed of rotation of the centrifugal regulator together with the regulatorshaft 4, each centrifugal body 3A,38 is forced to rotate around the respective journal and move outwardstowards the inside surface of the first hrake member 6.

At a predetermined rate of revolution of the regulator shaft, corresponding to the preset speed limit,the centrifugal force exerted on the centrifugal body exceeds the preset spring force of the spring, suchthat second end 3A.2, 38.2 ofthe centrifugal bodies pivot around the respective journal 7A,78 to engagewith projections 68 on the inside of the rotatable first brake member 6.

As iilustrated in Fig. 1 to 7 a mechanism for a safety device and a safety device according to the lnventionis show which reduces the speed limit for releasing the safety device to 0 m/s when the mechanism isactivated.

The mechanism, generally referenced 20, comprises an additional brake 21 having a brake housing 22enclosing a brake arrangement 25 and a rotatable brake shaft 23 .The brake housing has end portionsin which a respective end of the brake shaft 23 is rotatable mounted.

Fig. 1 shows that the mechanism comprises two trigger elements 30,308, which are arranged in thecentrifugai regulator 3. The first and second trigger elements 3OA,30B are arranged to extend into thecentrifugai regulator 3, in order to enable interaction with the first and second centrifugal bodies.

The trigger elements are coupled to the additional brake 21 of the mechanism. Each trigger element30A,3OB is arranged to cooperate with one respective centrifugal body 3A,3B and is capable of rotatingaround the regulator shaft of the safety device. in a rotating state, when the mechanism is inactive, thetrigger elements and the first and second drive gears and the brake shaft are brought to rotate by thecentrifugal regulator in response to the rotation of the regulator shaft.

Upon activation of the mechanism 20 , for example by a remote signal to disconnect the power supplyto the mechanism, the trigger elements 30A,30B are brought into a trigger state by the additional brake21 of the activated mechanism and are prevented by the additional brake from being rotated by thecentrifugal regulator. in the trigger state, the trigger elements being prevented from rotating by theadditional brake engage with respective centrifugal body of the centrifugal regulator to the centrifugalregulator 3 to release the safety device.

Since the trigger elements SOAÅOB are prevented from rotating, this causes the centrifugal bodies 3A,3B,which rotate with the shaft, to overcome the spring force which acts to hold the centrifugal bodies in aninner position. The trigger elements 30A,30B are thus arranged to actuate the centrifugal body lšAßl-S)to engage with the safety brake (6,8) to release the safety device. in response to further rotation of theregulator shaft 4 the centrifugal bodies 3A,3b are thus brought to rotate around respective journal 7A,7Band swing outwards to an outer position (seen in the radial direction) and thus trigger a bralsing actionof the safety brake and release the safety device.

Thereby the mechanism 20 provides that the speed at which the centrifugal regulator 3 is released isreduced to 0 m/s, such that the safety device 1 brakes the movement of the lift car and halts the lift caralso prior to that the actual speed of the lift exceeds the original preset speed limit for release of thesafety bralte. By activation of the mechanism 20 the motion of lift car can be stopped also when the liftspeed is lower than the speed limit at which the centrifugal regulator is set to lnitiate braking action bythe safety brake.

When the mechanism 20 is activated, the speed limit for releasing the safety device drops to 0 m/s, thusif the lift is moving unintentionally, the safety device will be released prevent the lift car from movingfurther. The safety device provided with the mechanism can thereby prevent unintended car movementof the lift car.

The mechanism can be activated for example by a rernotely arranged control system or a rnechanicalactuator connected to the lift system or a door at a floor plane.

As illustrated in Fig. 3 the mechanism further comprises a first drive gear 24 which is supported by theregulator shaft 4. The trigger elements 30A,30B are connected to the first drive gear 24 which ismounted, connected by a hearing having a hearing housing 28, to the regulator shaft 4 such that the firstdrive gear 24 may rotate free, and independent of, the regulator shaft.

The first drive gear 24, is provided within a widened portion of the housing 44 of the safety device. Thefirst drive gear 24 is provided on the opposite side of the centrifugal regulator seen from the coupling 5.

The mechanism further comprises a second drive gear 25 which is adapted to mesh and engage with thefirst drive gear 24 . The first drive gear 24 is provided with teeth which engage and mesh with teethprovided on the second drive gear 26 . The second drive gear 26 is connected to the rotatable brakeshaft 23 of the additional brake. 3D 11 As shown in Fig. 1 the hraite housing 22 is attached on the outside of the safety device housing 2 of thesafety device. The hrake shaft 23 and the second drive gear extend through an opening 53 of the safetydevice housing wall and into the widened portion 44 of the safety device housing such that the teeth ofthe second drive gear mesh and interact with the teeth of first drive gear.

The first drive gear 24 meshes with the second drive gear 26 such that the second drive gear, and thehraite shaft 23 , rotate together with the first drive gear 24 when the mechanism is not activated, thusthe first drive gear drives the second drive gear and the hrake shaft. When the mechanism is in aninactive state, and the reguiator shaft 4 rotates with a normal speed, he trigger elements šOA3ÛB andthe first and second drive gears 24,26 and the hrake shaft 23 are rotated hy the centrifugal regulator, As iilustrated in Fig. 3, the second drive gear 26 is suhstantiaiiy smaller than the first drive gear 24. Thisis advantageous in that the hrake force that has to he generated hy the hrake arrangement to hrake therotation of the second drive gear is reiativeiy small. The hrake arrangement can therefore he small andintegrated in the safety device housing and a compact safety device can thus he achieved.

The additional hrake further comprises a hrake arrangement 25 which is configured to, upon activationof the mechanism, to hrake and stop the rotation of the hrake shaft and the second drive gear.

The hrake arrangement 25 is adapted to he engaged with the hrake shaft when the mechanism is in anactive state in order to hrake and stop the rotation of the hrake shaft, the first and second drive gearand the rotation of the at ieast one trigger element, therehy hraking the trigger eiements to a standstiii,whereafter the trigger eiements engage with said centrifugai body of the centrifugai regulator to triggerthe safety device to he released.

The hrake arrangement 25 is disengaged from the hrake shaft when the additional brake 21 and themechanism is inactivated, wherein the trigger eiements 30A,30B and the first and second drive gearsand the hrake shaft may he brought to rotate again hy the centrifugai regulator. in Fig. 1-7 the iilustrated additional hraite 21 is configured as an eiectricaily controlied hrake, which isprovided with a hrake switch. The additional hrake 21 in this example is he activated hy disconnectionof power to the hrake switch, thus mechanism 20 is activated hy disconnection of power suppiy to theadditional hrake. The additional hrake may also he configured as an electromechanicai hrake or amechanicai hrake.

Furthermore, the additional hrake 21 may he remotely controlied hy a control system or a mechanicaiactuator connected to a iift system or a fioor piane or a door switch.

As shown in Fig. 3 the trigger elements 30A, 3GB are mounted diametricaliy opposite each other on asupport memher, a second yoke 27, connected to the first drive gear 24, such that the trigger elementsrotate with the first drive gear. The support member is fixediy connected to the first drive gear via ahearing housing and rotates together with the first drive gear. The second yoke 27 extends perpendicularto the reguiator shaft.

As shown in Fig. 3, the second yoi 12 respective centrifugal body 3A,3B of the centrifugal regulator. Each trigger element has a longitudinalaxis and may be formed as a cylinder such as a journal or pin, however, other designs are readily possible.

The mechanism 20 is arranged to interact with the centrifugal regulator in that the first and secondtrigger elements are brought to rotate hy the centrlfugal regulator in the rotatlng state, and in that thetrigger elements in the trigger state coact with the centrifugal force acting on the centrifugal bodies torotate outvvards and engage with the safety brake such that the safety device is released.

As illustrated in Fig 1 the trigger elements 3OA,30B are arranged diametrically opposite each other andsubstantially parallel to the regulator shaft 4 . The trigger elements are arranged to extend into thecentrifugal regulator, to enable interaction with the centrifugal bodies.

With reference to Fig. (SA-GB the centrifugal regulator accommodates the first and second triggerelement in one respective first and second space 15A,15B limited by the first end 3A.1 38.1 of one ofthe centrifugal bodies 3A,3B and the cam surface 3A3 38.3 of the other centrifugal body and a curvedguide surface (16A,16B) arranged on hub 14. The first space is further limited by the bracket 17 fixedlyconnected to the first yoke 9 supporting the centrifugal bodies.

The first and second trigger elements 3GA,3OB are arranged on a radial distance from the regulator shaft4 which is less than the radial distance to respective journal 7A,7B ofthe centrifugal bodies. ln the rotating state (see Fig. 6A), the first and second trigger elements may bear against respectivecurved guide surface l6A,l6B arranged on the hub 14, such that the curved guide surfaces and the hubbring the trigger elements and the first and second drive gear to rotate around the regulator shaft. Sincethe trigger element and the first and second drive gear are mounted by a hearing to rotate independentand free from the regulator shaft, the rotating of the same is easy and without significant resistance.

As shown in Fig. 68 the first and second centrifugal body šAßß are provided with one respective camsurface 3A.3 38.3 which is adapted to form a nip 19 with one respective curved guide surface l6A,16B.Thus a nip 19 is formed between the curved guide surface 16A,16B of the hub and the respective camsurface 3A.3 ,3B.3 located on the innermost portion of the centrifugal body 3A,3B in relation to theregulator shaft. ln the triggered state (see Fig. 5A), the first and second trigger elements interact withrespective cam surface 3A.3,3B.3 in said respective nip 19 to force the first and second centrifugal bodies3A,3B to rotate outwards to engage with the safety bralte, and thereby release the safety device The trigger elements SOAßOB are connected to the first drive gear 24 which is arranged to rotate freeand independent of the rotary shaft. When the centrifugal regulator is brought to rotate due to themovements of the lift car, the centrifugal regulator 4 interacts with the trigger elements EOAßOB anddrives the trigger elements and the first drive gear 24 to rotate together with the centrifugal regulator 4in a first direction of rotation, clockvvise in the figures.

As the first drive gear 24 mesh with the second drive gear 26 also the brake shaft 23 is brought to rotate.The bralte shaft is rotatably mounted in the brake housing 22 and may be brought to rotate together bythe first drive gear 24 as long as the additional hralte 21 is not activated. l-lowever, in case the additional brake 21 of the mechanism is activated, the brake arrangement 25 willbrake the rotation of the brake shaft 23, the first and second drive gears 24,26 and the trigger elements30A,3OB, which will be braked into a trigger state. 13 if the reguiator shaft is rotated when the mechanism is in the trigger state (the mechanism is activated),the brake force applied by trigger elements on the centrlfugai bodies counteracts the spring forceapplied to hold the centrifugal bodies in an inner position seen in the radiai direction. The triggerelements thus coact with centrifugal force to bring the centrifugai bodies to pivot outwards and engagewith the inside surface of the brake member 6, thereby reieaslng the safety device to brake furthermovement of the iift car.

The additional hrake 21 will thus override the spring force ofthe spring 18 in the centrifugai regulator 3which is preset to release the safety device when the lift car exceeds a preset speed limit. instead thespeed limit for release of the safety device is reduced to 0 m/s and thereby the safety device wiii brakethe movement of the lift car, for example to protect against unintended car movement.

The invention further reiates to a safety arrangement for a iift system cornprising at ieast one safetydevice having a mechanism as described above.

Fig . 8A shows a schematic circuit diagram of a safety arrangement comprising at ieast one safety devicehaving a mechanism as described above. The circuit diagram iilustrate how the brake ofthe mechanism,the safety device and associated switches are eiectricaiiy coupied to achieve several desirabie functionsby the safety arrangement.

The circuit diagram in Fig. 8A shows a safety arrangement for a lift system 100 comprising a safety devicewhich is provided with a brake switch 103 connected to the brake 21 of the mechanism 20 associatedwith the at safety device. The brake 21 is provided with the brake switch 103 eiectricaiiy coupied to theadditional brake. The brake switch is provided with a brake monitoring 102 adapted to rnonitorthe hrakeswitch and to communicate with a control system (not shown). The brake switch is connected to theadditional brake of a mechanism for a safety device as previously described. The additional brake 21 isactivated when the brake switch is de-energized.

The safety arrangement is further provided with a safety device switch 105, which is automaticallyopened when the safety device has been reieased.

The safety arrangement further comprises a door switch 104 which is adapted to be eiectricaiiy coupiedto the brake switch 103. The door switch 104 is associated with a ianding for the iift car, and is adaptedto be opened when the iift car is haited at a fioor piane or stands by a ianding.

Furthermore, the safety device switch 105 is adapted to be eiectricaiiy connected in series with the doorswitch 104.

The door switch 104 being eiectricaiiy coupled to the brake switch 103, thereby disconnects the brakeswitch from the power suppiy when the door switch is opened. As a conseouence, the additional brake21 and the mechanism 20 are activated and will brake the trigger elements 30A,30B of the mechanisminto said trigger state, and the safety device is triggered to reduce the speed limit for reieasing the safetydevice to 0 m/s, thus the safety device is thus ready to be released if any unintended car movementsoccur.

On the contrary, during normal operation of the iift, the door switch 104 is closed, the brake switch 103is energized and thus the brake 21 and the mechanism are inactive, and the safety device may insteadbe released if the preset speed limit of the iift is exceeded. 14 The circuit diagram of Fig. 8A further shows that the safety device switch 105 is eiectricaiiy coupied tothe at ieast one hrake switch via the door switch 104. Provided that the door switch 104 is ciosed, thesafety device switch 105 may aiso controi the hrake switch 103 to activate the mechanism 20. The safetydevice switch 105 is adapted to he automaticaiiy opened in response to a reieasing action of the safetydevice. The safety device switch 105 is thus adapted to disconnect the hrake switch 103 from the powersuppiy when the safety device switch is opened. For safety reasons it can therehy he ensured that thebrake switch 103 is deenergised and the mechanism is activated if the safety device has heen reieased.

The safety arrangement further comprises an emergency operation switch 106 eiectricaiiy coupied,connected, in paraiiei to the safety device switch 105. The safety arrangement has a power suppiy 107adapted to suppiy power to the safety arrangement, however, an emergency power suppiy 108, forexampie a battery, is aiso provided to be used if there is a major power faiiure. The emergency powersuppiy 108 is activated hy an emergency power suppiy activation 109.

The emergency operation switch 106 enahies resetting of the safety device after the safety device hasbeen reieased. When the emergency operation switch 106 is ciosed and the door switch is ciosed, poweris provided to the hrake switch 103 and the safety device with the mechanism can be reset.

The circuit diagram of Fig. 85 iiiustrates a safety arrangement for a iift system 200.

This safety arrangement comprises two or more safety devices, each safety device being provided witha mechanism 20 for trigga-ring the respective safety device to reduce the speed limit for reieasing thesafety device to 0 m/s. This type of safety arrangement 200 is particuiariy advantages on muiti-mastinstaiiations , where a piuraiity of safety devices are instaiied.

The safety arrangement 200 is configured to interconnect a piuraiity of safety devices in order to enahiethat if one safety device is reieased to hrake the movement of a iift car, aiso further safety devicesassociated with the safety arrangement 200 are triggered to reduce the speed iimit to 0 m/s.

By this safety arrangement it is possihie to ensure that aii of the safety devices in the safety devices areactivated, even though toierances in the safety devices cause them to have siightiy different presetspeed iimits. As soon as one of the safety devices is activated hy respective mechanism, the speed iimitof any unactuated safety devices wiii drop to 0 m/s, which means that they wiii he activated for aiicontinued motion. Severai safety devices may therehy safeiy he used on one and the same iift.

Fig. Sh shows a schematic circuit diagram of a safety arrangement 200 comprising two safety devices,where each safety device (not shown) is provided with a mechanism 20 for triggering respective safetydevice. The iiiustrated exampie describes a schematic circuit diagram for a iift car associated with a muiti-mast instaiiation. The switches of the safety arrangement 200 provide the same functions as the safetyarrangement 100.

As shown in the schematic circuit diagram of Fig. Sh the safety arrangement for a iift system 200 furthercomprising a first safety device and a second safety device (not shown in the diagram). The first safetydevice is further provided with a first safety device switch 205a and a first hrake switch 203a which areeiectricaiiy coupied to each other, and the second safety device is provided with a second safety deviceswitch 205h and a second brake switch 203h which are eiectricaiiy coupied to each other. Furthermore,the first safety device switch 205a is adapted to be automaticaiiy opened in response to a reieasing action of the first safety device, and the second safety device switch 205b is also adapted to beautomatically opened in response to a reieasing action of the second safety device.

Furthermore, each brake switch ZOEša, 203b is provided with brake monitoring 202a, 202b adapted tomonitor the brake switch and to communicate with a control system (not shown).

The safety arrangement 200 further comprises at least one door switch 204 which is adapted to beeiectrically coupled to the first and second brake switch 203a, 203b. The door switch 204 is associatedwith a landing for the lift car, and is adapted to be opened when the lift car is halted at a floor plane orstands by a landing.

Fig. 8b further iliustrates that the first and second brake switches 203a, 203b are eiectrically coupled,connected, in parailei to the door switch 204. The door switch 204 thus controls the power supply toboth of the first and second brake switch. The safety arrangement thus ensures that when the doorswitch is open, the power is disconnected to both of the brake switches, whereby both the first andsecond additionai brake are activated to trigger respective safety device to reduce the speed limit to 0m/s, as described above. This ensures that no unintended car movement will occur.

A further function provided by the safety arrangement for a lift system 200 is that it can be ensured thatthe speed limit of all interconnected safety devices is reduced to 0 m/s as a consequence of one of thesafety devices being released. This function increases the safety in the lift system, and furthermore theload can be distributed over all safety devices, which also improves the safety and functioning of the liftsystem.

Fig. 8b further illustrates that the first safety device switch 205a and the second safety device switch205b are interconnected, eiectrically coupled, in series into the circuit.

This is advantageous in that in case the first safety device switch 205a or the second safety device switch205b are opened due to that one of the first or the second safety device has been released to preventthe lift car from further motion, for example by exceeding the preset speed limit, this will cause thecorresponding first or second safety device switch 205a, 205b to be opened. As a consequence, sincethe safety device switches ZOSa, 205b are connected in series, the power supply to both the first brakeswitch 203a and to the second brake switch 203b is disconnected.

This results in that the first and the second additional braltes are activated to trigger respective safetydevice to reduce the speed limit to 0 m/s.

The safety arrangement for a lift system thus ensures that all of the safety devices in the series areactivated, even though toierances in the safety devices cause them to have slightiy different presetspeed iimits. As soon as one of the safety devices is activated by respective mechanism, the speed limitof any unactuated safety devices will drop to O m/s, which means that they will be activated for allcontinued motion. This is a way to safely use several safety devices on one and the same lift.

Claims

1. 3G 4G CLAEMS 1. 16 A mechanism (20) for a safety device for lift car comprising a hrake (21) and at least one trigger element (3OA,30B) which is coupled to the hrake, wherein the at least one trigger element being capable of rotating around a regulator shaft ofthe safety device, wherein the at least one trigger element being brought into a trigger state hy the lorake (21)when the mechanism is activated, and in the trigger state, the at least one trigger element (3OA,30B is prevented from rotating hythe hralte (21), wherein the at least one trigger element (SOAßOB) is connected to a first drive gear (24)wherein the brake (21) comprises a rotatahie bralte shaft (23) provided with a second drive gear(26) which is engaged with the first drive gear (24), and the brake comprises a hrakearrangement (25) adapted to he engaged with the brake shaft when the mechanism is in anactive state for loraking the rotation of the brake shaft, the first and second drive gear and theat least one trigger element. The mechanism according to claim 1 characterized in that the at least one trigger element(3OA3OB) is mounted on a first yolte (27) connected to the first drive gear (24), and that the atleast one trigger element comprises a first end which is mounted to the yoke and a second endused for actuating a centrifugal regulator of the safety device. The mechanism according to claim 2 comprising at least two trigger elements (30A,30B)mounted on the first yoke (27) having two ends, and that the trigger elements are mounteddiametrically opposite each other, where the trigger elements are mounted in each end of theyoke respectively. The mechanism according to any of the previous claims characterized the at least one triggerelement (3ÛA3OB) comprises an axel har or a pin. The mechanism according to any of the previous claims characterized in that the diameter ofthefirst drive gear (24) is substantially larger the diameter of the second drive gear (26). The mechanism according to any of the previous ciaims characterized in that the brake (21)comprises an electrically controlled hrake, and a hrake switch (103) which is remote controlled,and that the mechanism (20) is activated hy disconnection of power supply to the hralte switch. A Safety device (l) for protecting against unintended car movement of a lift car comprising aregulator shaft (4) which is brought to rotate due to a coupling (5) to the motion of the lift car,a safety bralte (6,8), a centrifugal regulator (3) connected to the regulator shaft, said centrifugalregulator being adapted to couple the regulator shaft to the safety bral and a mechanism (20) comprising an additional hrake (21) and at least one trigger element(3OA3OB) which is coupled to the additional brake, 10. 11. 1

2. 1

3. 17 wherein the at least one trigger element BÜABGB) being capable of rotating around a regulatorshaft (4) of the safety device, wherein the at least one trigger element (3OA,3OB) being brought to rotate around the regulatorshaft (4) by the centrifugal regulator in a rotating state, wherein the at least one trigger element (30A,3OB) being brought into a trigger state by theadditional brake when the mechanism (20)is activated, wherein, in the trigger state, the at least one trigger element (30A30B) being prevented fromrotating by the additional brake and the at least one trigger element being arranged to triggerthe centrifugal regulator (3) to release the safety device. The safety device according to claim 7 characterized in that the at least one trigger element(BOAÅOB) being arranged to actuate the centrifugal body (3A,3B) to engage with the safety brake(6,8) to release the safety device. The safety device according to claim 7 or 8 characterized in that, the mechanism (20) cornprlses a first drive gear (24) which is supported by the regulator shaftand is mounted to rotate independent of the regulator shaft, and that the at least one trlgger element (EOABOB) is connected to the first drive gear. The safety device according to any of claims 7-9 characterized in that, the mechanism (20) comprises a second drive gear (26) which is adapted to engage with the firstdrive gear (24), a rotatable brake shaft (23) connected to the second drive gear (26) , and a brake arrangernent (25) adapted to be engaged with the brake shaft (23) when themechanism is in an active state in order to bralte the rotation of the first drive gear and therotation of the at least one trigger element. The safety device according to any of claims 7-10 characterized in that, the at least one trigger element (3OA3OB) and the first and second drive gears (2426) and thebrake shaft (23) are adapted to be rotated by the centrifugal regulator when the mechanism isin an inactive state. The safety device according to any of claims 7-11 characterized in that the additional brake (21)comprises an electrically controlled brake, and that the mechanism (2Û) is activated bydisconnection of power supply to the additional brake. The safety device according to any of claims 7-12 characterized in that the centrifugal regulator(3) cornprises a first and a second centrifugal body (3A,3B) which are connected by means ofjournals to a first yol and that the mechanism (20) comprises a first and a second trigger element (30A3OB) which aremounted diarnetrically opposite each other on a respective end ofa second yoke (27) connectedto the first drive gear (24), said second yoke (27) being mounted to be rotated around theregulator shaft (4). 2G 4G 1

4. 1

5. 1

6. 1

7. 1

8. 1

9. 20. 21. 22. 18 The safety device according to any of ciaims 7-13 characterized in that the at least one triggerelement (30/1305) cornprises an axel or a pin, and the at least one trigger element has alongitudinal axis which is parallel to the regulator shaft. The safety device according to any of claims 7-14 characterized in that the diameter of the firstdrive gear (24) is substantially larger the diameter of the second drive gear (26). The safety device according to any of clairns 7-15 characterized in that the mechanism (20) isadapted in order to be rernotely activated by a control system. The safety device according to any of ciaims 7-16 characterized in that the centrifugai regulator(3) cornprises a hub (14) which is connected to the shaft to rotate together with the regulatorshaft (4) , and that the hub is fixedly connected to the regulator shaft by a wedge and grooveconnection (50) in order to lock the hub (14) to the regulator shaft. The safety device according to any of claims 7-17 characterized in that the centrifugal regulatorcomprises a hub (14) which is connected to the shaft to rotate together with the shaft, and thatthe regulator shaft is provided with helical running splines (13), and that a hub ofthe centrifugalregulator is provided with threads (14A) in order to enable an axial translation of the centrifugairegulator along the regulator shaft. The safety device according to any of clairns 7-18 characterized in that the first and secondtrigger elements (3OA30B) are arranged to extend into the centrifugai regulator (3), in order toenable interaction with the first and second centrifugai bodies, The safety device according to any of claims 7-19 characterized in that the centrifugal regulator(3) is adapted to accornmodate the first and second trigger elements (3ÛA,3OB) in a first andsecond space (15A,15B) limited hy the first end (3A.1 ,3B.1)of one of the centrifugal bodies(3A,3B) and a cam surface (3A.3 38.3) of the other centrifugal body and a curved guide surface(löﬁtlßß) on the hub (14), and that the first and second trigger elements are arranged to beguided by the curved guide surface (16A,16B) to rotate around the regulator shaft (4) in therotating state. The safety device according to any of claims 7-2G characterized in that the first and secondcentrifugal body (3A3B) are provided with one respective cam surface (EEAB 38.3) which isadapted to form a nip (19) with one respective curved guide surface (16A,15B), and that the thefirst and second trigger elements (EOABGB) interact with the respective cam surface (3A3 33.3)in said respective nip (19) to force the first and second centrifugal bodies to rotate outwards toengage with the safety brake (6,8). A safety arrangement (100,200) for a lift system cornprising at least one safety device (1) according to any of the claims 7-21, a power supply (107207) adapted to supply power to the safety arrangement,at least one door switch (104,204) associated with a landing for the lift car, 23. 24. 19 wherein the at least one safety device is further provided with a brake switch (103,203a,203b)connected to the additional brake of the mechanism (26) associated with the at least one safetydevice, the at least one hrake switch llßšßüšaﬁílšb) being adapted to be electricaily coupied to the atleast one door switch (104304), and the at least one door switch l104,204lheing adapted to be opened when the lift car standsby a iandlng, wherein the at least one door switch (lüli-JG-ilbeing adapted to disconnect the brake switch(lO3,203a,203bl from the power supply (161207) when the at least one door switch (1Û4,2(l4)is opened whereby the safety device is triggered to he released. The safety arrangement for a lift system according to claim 22 comprising that the at least one safety device is further provided with a safety device switch(1G5,205a,2(l5b) which is adapted to be opened in response to a releasing action of the safetydevice, wherein the at least one safety device switch (l05,205a,205b) is electricaily coupled tothe at least one brake switch (103,203a,2tl3b) , and the at least one safety device switch (105,205a,2t)5bl is adapted to the at least on hrakeswitch from the power supply when the at least one safety device switch is opened. A safety arrangement for a lift system according to ciairn 22 cornprising at least a first safety device and a second safety device, that the first safety device being provided with a first safety device switch i2ü5al and a first hrakeswitch (203a) which are electricaily coupled to each other, that the second safety device being provided with a second safety device switch (205b) and asecond brake switch (ZOBb) which are electricaily coupled to each other, that the first safety device switch (205a) is adapted to be opened in response to a releasingaction of the first safety device, that the second safety device switch (205b) is adapted to be opened in response to a releasingaction ofthe second safety device, that the first safety device switch iIZOSa) and the second safety device switch iZOShl areelectricaily coupled in series , wherein the power supply to the first hrake switch (203a) and to the second brake switch (20%)is disconnected when the first safety device switch (Zﬁäa) or the second safety device switch(ZOSb) are opened.