Elevator safety arrangement configured to detect a load on a working platform and elevator

Abstract

The invention relates to an elevator safety arrangement comprising a hoistway; an elevator car mounted in the hoistway; a working platform mounted on top of the roof the elevator car; at least one sensing arrangement for sensing load of the working platform and at least one balustrade. Said balustrade is mounted on the working platform such that its weight is carried by the working platform, and in that it is movable between a substantially upright position and a substantially horizontal position.

Claims

1. An elevator safety arrangement, comprising: a hoistway; an elevator car mounted in the hoistway; a working platform mounted on top of a roof of the elevator car; at least one balustrade mounted on the working platform such that a weight of the at least one balustrade is carried by the working platform, the at least one balustrade movable between a substantially upright position and a substantially horizontal position; and at least one first sensing arrangement including a first sensor horizontally adjacent to a planar upper tread surface of the working platform, the first sensor configured to simultaneously sense a load on the working platform and indirectly sense a load on the at least one balustrade in both the substantially upright position and the substantially horizontal position by sensing a position of the working platform, the position of the working platform varying based on a change in the weight of the at least one balustrade carried by the working platform due to the load on the at least one balustrade when the at least one balustrade is in either the substantially upright position or the substantially horizontal position.

2. The elevator safety arrangement according to claim 1, wherein when the at least one balustrade is at the substantially horizontal position, the at least one balustrade lies over the planar upper tread surface of the working platform such that the at least one balustrade at least partially covers the planar upper tread surface of the working platform.

3. The elevator safety arrangement according to claim 1, wherein the at least one balustrade is mounted on the working platform pivotally between the substantially upright position and the substantially horizontal position.

4. The elevator safety arrangement according to claim 1, wherein the working platform comprises: the planar upper tread surface for a person to stand on, and a plate vertically above a level of the planar upper tread surface of the working platform, and wherein the first sensor for sensing the position of the working platform is vertically between the roof of the elevator car and the plate.

5. The elevator safety arrangement according to claim 4, wherein the working platform comprises: a lateral border structure extending upwards above the level of the planar upper tread surface, and the plate is fixedly connected with the lateral border structure.

6. The elevator safety arrangement according to claim 5, wherein the first sensor for sensing the position of the working platform is horizontally adjacent to the planar upper tread surface of the working platform and vertically between the roof of the elevator car and the plate.

7. The elevator safety arrangement according to claim 4, wherein the first sensor for sensing the position of the working platform comprises: a sensor body; and a sensor head, and wherein the working platform is connected to the plate such that vertical movement of the working platform moves the plate towards the roof of the elevator car such that the plate compresses the sensor head.

8. The elevator safety arrangement according to claim 7, wherein the sensor head is vertically movable relative to the sensor body.

9. The elevator safety arrangement according to claim 1, further comprising: a second sensing arrangement for sensing a position of the at least one balustrade.

10. The elevator safety arrangement according to claim 9, wherein the second sensing arrangement comprises: at least one second sensor for sensing the position of the at least one balustrade, and wherein the at least one balustrade is mounted on the working platform pivotally around a pivoting fulcrum, and the at least one second sensor for sensing the position of the at least one balustrade is beside the pivoting fulcrum of the at least one balustrade.

11. The elevator safety arrangement according to claim 10, wherein the at least one second sensor for sensing the position of the at least one balustrade comprises: a sensor body; and a sensor head horizontally movable relative to the sensor body, and wherein the at least one balustrade is arranged to move the sensor head horizontally when pivoted.

12. The elevator safety arrangement according to claim 9, wherein the at least one balustrade comprises: a cam member pivotal together with the at least one balustrade, the cam member including one or more protrusions and depressions, and wherein a sensor head of the second sensing arrangement is against the cam member for being actuated by aid of at least one protrusion and at least one depression of the cam member.

13. An elevator safety arrangement comprising a hoistway; an elevator car mounted in the hoistway; a working platform mounted on top of a roof of the elevator car, the working platform including a planar upper tread surface for a person to stand on, and a plate vertically above a level of the planar upper tread surface; and at least one first sensing arrangement for sensing a load of the working platform, the at least one first sensing arrangement including a sensor horizontally adjacent to the planar upper tread surface of the working platform and vertically between the roof of the elevator car and the plate, the sensor configured to sense a position of the working platform.

14. An elevator comprising: the elevator safety arrangement of claim 1.

15. The elevator safety arrangement of claim 9, wherein the second sensing arrangement is configured to sense whether the position of the at least one balustrade is the substantially upright position or is the substantially horizontal position.

16. The elevator safety arrangement of claim 15, wherein the second sensing arrangement comprises: a pair of second sensors adjacent to a cam member, the cam member configured to pivot with the at least one balustrade when the at least one balustrade moves between the substantially upright position and the substantially horizontal position.

17. The elevator safety arrangement of claim 13, wherein the sensor is configured to simultaneously sense the load on the working platform and indirectly sense a load on at least one balustrade based on a change in a weight of the at least one balustrade carried by the working platform due to the load on the at least one balustrade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the present invention will be described in more detail by way of example and with reference to the attached drawings, in which

(2) FIG. 1 illustrates a preferred embodiment of an elevator safety arrangement.

(3) FIG. 2 illustrates preferred details of the elevator safety arrangement, when the working platform and the balustrade of the elevator safety arrangement are in a first state.

(4) FIG. 3 illustrates preferred details of the elevator safety arrangement, when the working platform and the balustrade of the elevator safety arrangement are in a second state.

(5) FIGS. 4a-4d illustrate preferred details of optional further features of the safety arrangement.

(6) The foregoing aspects, features and advantages of the invention will be apparent from the drawings and the detailed description related thereto.

DETAILED DESCRIPTION

(7) FIGS. 1-3 illustrate an embodiment of an elevator safety arrangement comprising a hoistway 1, an elevator car 2 mounted in the hoistway 1, a working platform 3 mounted on top of roof 4 the elevator car 2, at least one sensing arrangement 5 for sensing load of the working platform 3. The working platform 3 comprises a planar upper tread surface 3a for a person to stand on. The elevator safety arrangement further comprises at least one balustrade 6 mounted on the working platform 3 such that its weight is carried by the working platform 3, and it is movable between a substantially upright position and a substantially horizontal position. By said sensing arrangement 5 a load placed on the working platform, were it a person or his belongings, will be detectable. The load will be detectable when it is placed to be supported by the planar upper tread surface 3a of the working platform 3 but also when the load is placed to be supported by the balustrade because the balustrade is carried by the working platform 3. This is particularly advantageous because should the service person forget his belongings, such as his tool box, on the horizontally tilted balustrade upon leaving the hoistway, this will also be detectable, and thereby actions for avoiding crushing of the toolbox between the car and the hoistway ceiling can be taken.

(8) In the preferred embodiment, the balustrade 6 is a planar structure, such as a plate or a structure comprising plurality of members, such as beams, placed on the same plane. Thus, it can be simply arranged in said substantially horizontal position where it requires only little space in vertical direction. As showed in FIG. 1, the elevator can comprise more than one of said balustrades 6. If these are to be folded partially over each other, as it is the case in the presented embodiment, it may be needed that one of the balustrades 6 is not perfectly horizontal in said substantially horizontal position.

(9) So as to enable reacting to sensing of an increase of load of the working platform 3, the sensing arrangement 5 is preferably connected electrically to the elevator control system. The elevator control system can be adapted to perform one or more predefined actions when one or more criteria are met, said criteria including sensing of an increase of load of the working platform 3. The elevator control system can in this context be understood broadly to include the normal elevator control unit but also the safety circuit of the elevator. Said predefined actions may include one or more of the following: elevator mode change from normal operation mode to service operation mode, stop of movement of the elevator car, prevention of further starts of the elevator car in response to signals from passengers.

(10) As disclosed in FIGS. 1-3, the elevator safety arrangement is further such that in said substantially horizontal position, said balustrade 6 lies over the planar upper tread surface 3a of the working platform 3 covering it at least partially. Thereby it blocks direct stepping on the planar upper tread surface 3a covered by it. The balustrade 6 extends in said substantially horizontal position along the planar upper tread surface 3a, preferably parallelly therewith, but if a slight angle between the balustrade 6 and the planar upper tread surface 3a is needed for some reason, then it is preferably less than 10 degrees, more preferably less than 5 degrees. The configuration being parallel, as far as possible, ensures low overall structure for the equipment placed on top of the elevator car 2. Correspondingly, the balustrade 6 extends in said substantially upright position straight upwards, but if a slight angle between the balustrade 6 and vertical plane is needed for some reason then it is preferably less than 10 degrees, more preferably less than 5 degrees.

(11) As disclosed in FIGS. 1-3, the elevator safety arrangement is further such that said balustrade 6 is mounted on the working platform 3 pivotally, preferably via one or more hinges, between said substantially upright position and said substantially horizontal position. When the car 2 is in normal operation mode, the balustrade 6 is to be in said substantially horizontal position. Upon entering the hoistway, by stepping on top of the car roof 4, the service person can manually pivot the balustrade 6 up to said substantially upright position, wherein it serves as a safety blockage against falling from the car roof 4.

(12) In the following preferred details of the sensing arrangement 5 for sensing load of the working platform 3 are discussed. Said sensing arrangement 5 for sensing load of the working platform 3 comprises a sensor 5a for sensing position of the working platform 3, as illustrated in Figures. Said sensor 5a is also referred to as a position sensor. The sensing arrangement 5 is arranged to sense the load based on position of the of the working platform 3. The working platform 3 comprises a planar upper tread surface 3a for a person to stand on, and a detent member 3b above the level L of said planar upper tread surface 3a of the working platform 3, and the position sensor 5a is in vertical direction between the car roof 4 and the detent member 3b. This structure provides that the position sensor 5a does not decrease the height of the safety space, i.e. the distance between the planar upper tread surface 3a of the working platform 3 and the ceiling of the hoistway 1 can be maximized. Structure of the working platform 3 can thus also generally be maintained low. In the preferred embodiment illustrated, the position sensor 5a is beside the planar upper tread surface 3a of the working platform 3. No planar upper tread surface 3a of the working platform 3 needs to be located on top of the position sensor 5a. Thereby their structures do not pile up vertically and the overall structure can be made low.

(13) The above mentioned aspects are implemented in the preferred embodiment more specifically such that the working platform 3 comprises a lateral border structure 3c extending upwards above the level of the planar upper tread surface 3a, and the detent member 3b is fixedly connected with the lateral border 3c. Said lateral border structure 3c is preferably an upright plate section, a so called kick plate section. Said upright plate section and said planar upper tread surface 3a are preferably integral parts of a bent metal plate. Thus, the structure is simple to form by bending. Alternatively, said lateral border structure 3c can be an upright plate section in the form of a separate edge profile part, preferably made of metal, such as of aluminum for instance.

(14) The sensor head 5a2 is preferably vertically movable relative to the body 5a1. The aforementioned position sensor 5a preferably comprises a sensor body 5a1 and a sensor head 5a2, and vertical movement of the working platform 3 is arranged to bring the detent member 3b downwards and towards the car roof 4, i.e. downwards, such that it compresses the sensor head 5a2. The resulting position is disclosed in FIG. 2.

(15) For holding the working platform from moving freely, said sensing arrangement 5 preferably comprises a restriction means therefor. In the preferred implementation of the holding means illustrated in FIGS. 1-3 comprise at least one spring 5b arranged to resist downwardly directed movement of the working platform 3. The holding means, i.e. the spring in this case, holds the working platform 3 in an upper position, and resists movement thereof downwards to its lower position. By dimensioning of the spring 5b, sensitivity of the sensing arrangement 5 can be adjusted. The sensing arrangement 5 is preferably adjusted such that a weight of 10 kg or more can move the working platform 3 downwards such that the sensor head 5a2 is compressed. The sensing arrangement 5 preferably further comprises a limit stopper 12 for delimiting downwards directed movement of the working platform 3. The range of downwards directed movement of the working platform 3 is preferably delimited by the limit stopper 12 to be 1 cm or less. Owing to the limit stopper 12, the moving range of the sensor head 5a2 will not be exceeded and overload and breaking thereof is avoided.

(16) The arrangement preferably further comprises a sensing arrangement 7 for sensing position of the movable balustrade 6. A preferred implementation of the sensing arrangement 7 is illustrated in FIGS. 1-3. In the presented embodiment, said sensing arrangement 7 for sensing position of the movable balustrade 6 comprises at least one sensor 7a1,7a2 for sensing position of the balustrade 6. Said sensor 7a1,7a2 is also elsewhere referred to as a position sensor.

(17) Said balustrade 6 is mounted on the working platform 3 pivotally between said substantially upright position and said substantially horizontal position, in particular around a fulcrum f, and said at least one sensor 7a1,7a2 is beside the pivoting fulcrum f of the balustrade 6. Thereby, when the balustrade is in its horizontal position as illustrated in FIGS. 1 and 2, the at least one sensor 7a1,7a2 does not increase the height of the overall structure at all, or at least not significantly.

(18) As for the preferred structure of said at least one sensor 7a1,7a2, it preferably comprises a sensor body 8a1,8b1 and a sensor head 8a2,8b2, as illustrated. The preferably, the sensor head 8a2,8b2 is horizontally movable relative to the sensor body 8a1,8b1 as then the sensor is simple to make to have a low structure. The balustrade 6 on the other hand, is preferably arranged to move the sensor head 8a2,8b2 horizontally when pivoted.

(19) FIG. 2 illustrates the balustrade 6 being in said substantially horizontal position. When the balustrade 6 is pivoted, it ends up in position as disclosed in FIG. 3. The balustrade 6 is preferably arranged to move, and thereby actuate, the sensor head 8a2,8b2 with a cam member 9. The balustrade 6 then preferably comprises a cam member, such as a cam disc 9 having a non-circular rim, and pivotal together with the balustrade 6 and comprising one or more protrusions 11 and depressions 10a, 10b. The sensor head 8a2,8b2 is placed against the cam member for being actuated by aid of at least a protrusion and at least a depression of the cam member 9, in the presented case particularly against the non-circular rim thereof. The sensor head 8a2,8b2 is arranged to be compressed by the protrusions 11 when the balustrade is pivoted such that the sensor head 8a2,8b2 is at a point of a protrusion 11, said compression being relieved when the sensor head 8a2,8b2 is at a point of a depression 10a, 10b. The sensor itself can contain a returning spring whereby when the sensor head 8a2,8b2 comes to be at a point of a depression 10a, 10b, the sensor head 8a2,8b2 is freed to move into it.

(20) In the presented embodiment, said at least one sensor 7a1,7a2 comprises two of said sensors 7a1,7a2 adjacent the cam member 9, and said cam member 9 comprises two of said depressions 10a, 10b. One 10b of the depressions 10a, 10b is at the point of one 7a2 of the sensors 7a1,7a2 when the balustrade 6 is in said substantially upright position and the other 10a of the depressions 10a, 10b being at the point of the other 7a1 of the sensors 7a1,7a2 when the balustrade 6 is in said substantially horizontal position. In the presented embodiment, said two of said sensors 7a1,7a2 are on opposite lateral sides beside the cam member 9, in order to maintain the structure low. In the presented embodiment, said two depressions 10a, 10b are at 90 degrees from each other.

(21) So as to enable reacting to sensing of pivoting of the balustrade 6 to its substantially upright position, the sensing arrangement 7 is preferably connected electrically to the elevator control system. The elevator control system can be adapted to perform one or more predefined actions when one or more criteria are met, said criteria including sensing the balustrade 6 is away from its substantially horizontal position. The elevator control system can in this context be understood broadly to include the normal elevator control unit but also the safety circuit of the elevator. Said predefined actions may include one or more of the following: elevator operation mode change from normal operation mode to service operation mode, stop of movement of the elevator car, prevention of further starts of the elevator car in response to signals from passengers. These criteria, particularly for allowance of service operation mode, preferably further include sensing that the balustrade 6 is in said substantially upright position. This will ensure that the balustrade 6 is not only tilted up but tilted up to its correct position.

(22) FIGS. 4a-4d illustrate details of optional further features of the safety arrangement. The arrangement presented in FIGS. 1-3 comprises further a first stopper member 13 fixed on the balustrade 6. The first stopper member 13 is thereby pivotal around the pivoting fulcrum f of the balustrade 6 together with the balustrade 6. The first stopper member 13 is arranged to pivot, when the balustrade 6 is pivoted from said substantially horizontal position to said substantially upright position, together with the balustrade 6 to be aligned with a second stopper member 14 mounted in the hoistway structures, in particular on a guide rail 15 for guiding the elevator car 2 (or alternatively a guide rail for guiding the counterweight) such that the second stopper member 14 is in the path of the first stopper member 13. Thus, should the car 2 be moved, the first and second stopper member 13,14 will eventually collide as illustrated in FIG. 4d, and further movement of the car 2 will be blocked. The second stopper member 14 preferably includes a buffer element 14a for softening the collision between the stopper member 13 and 14, for example polyurethane buffer, gas spring or similar.

(23) When the car 2 is in normal operation mode, the balustrade 6 is in said substantially horizontal position, and the first stopper member 13 is not aligned with said second stopper member 14. As illustrated in FIG. 4b, upon entering the hoistway 1, by stepping on top of the car roof 4, the service person can manually pivot the balustrade 6 up to said substantially upright position, wherein it serves as a safety blockage against falling from the car roof 4. Simultaneously with pivoting of the balustrade 6, the first stopper member 13 fixed thereon becomes pivoted to be aligned with said second stopper member 14 in accordance with FIG. 4c and as described above. Subsequent movement of the car 2 upwards will cause the first and second stopper member 13,14 to collide, which will block further movement of the car 2.

(24) In general, it is preferred that in the service operation mode, the elevator does not serve passengers automatically. Particularly, the elevator car is not movable automatically in response to passenger signals received from user interfaces for passengers, such as ones located at landings and/or inside the elevator car. However, preferably the elevator car 2 is movable by aid of manually operable service drive equipment, such as a user interface for a service person, which user interface is preferably located on top of the elevator car 2.

(25) In general, each said sensor 5a,7a1,7a2 can be any kind of a sensor suitable for sensing position. It can be in the form of a switch, such as an NC- or NO-switch, for instance. This type of sensors have the advantage that they are reliable and simply usable for safety related limit monitoring. They are simply connectable with a safety circuit of the elevator, for instance. Also other kind of sensors suitable for this function are commercially available and usable instead of a switch type position sensor described.

(26) It is to be understood that the above description and the accompanying figures are only intended to teach the best way known to the inventors to make and use the invention. It will be apparent to a person skilled in the art that the inventive concept can be implemented in various ways. The above-described embodiments of the invention may thus be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that the invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.