Abstract
An elevator car (1) defining an interior space (2) for accommodating passengers and/or cargo. The elevator car (1) includes a working platform (12) moveable between a stowed position, above the interior space (2), and an operational position, suspended within the interior space (2), a hoisting device (18) located at the working platform (12) and a tension member (16a, 16b) connected to the hoisting device (18) and connected to the working platform (12) such that a suspending portion (17a, 17b) of the tension member (16a, 16b) suspends the working platform (12). The hoisting device (18) is configured, when actuated, to alter the length of the suspending portion (17a, 17b), so as to hoist the working platform (12) between the stowed position and the operational position.
Claims
1. An elevator car (1) defining an interior space (2) for accommodating passengers and/or cargo, the elevator car (1) comprising: a working platform (12) moveable between a stowed position, above the interior space (2), and an operational position, suspended within the interior space (2); a hoisting device (18) mounted to the working platform (12); a tension member (16a, 16b) connected to the hoisting device (18) and connected to the working platform (12) such that a suspending portion (17a, 17b) of the tension member (16a, 16b) suspends the working platform (12), wherein the hoisting device (18) is configured, when actuated, to alter the length of the suspending portion (17a, 17b), so as to hoist the working platform (12) between the stowed position and the operational position; wherein the hoisting device (18) is attached to an underside (14) of the working platform (12), the underside of the working platform facing the interior space.
2. The elevator car (1) of claim 1, wherein the hoisting device (18) maintains said suspending portion at a given length, unless actuated by the application of a force.
3. The elevator car (1) of claim 1, wherein the hoisting device (18) is rotationally driven, configured to alter the length of the suspending portion (17a, 17b).
4. The elevator car (1) of claim 3, wherein the hoisting device (18) comprises a worm screw (20) and a sliding member (22) configured to slide along the worm screw (20) when the worm screw (20) is rotationally driven, wherein the tension member (16a, 16b) is connected to the sliding member (22), such that when the sliding member (22) moves the length of the suspending portion (17a, 17b) is altered.
5. The elevator car (1) of claim 1, wherein the hoisting device (18) is manually actuatable.
6. The elevator car (1) of claim 1, wherein the hoisting device (18) comprises at least one deflector (24a, 24b), and wherein the tension member (16a, 16b) is arranged to pass over the at least one deflector (24a, 24b) in a 3:1 roping arrangement.
7. The elevator car (1) of claim 1, further comprising a support frame (8) located at an upper part of the elevator car (1) and a connection mechanism (11), the connection mechanism (11) connected to the support frame (8) and connected to the working platform (12).
8. The elevator car (1) of claim 7, wherein the connection mechanism (11) is arranged to exclusively support the weight of the working platform (12) in the operational position.
9. The elevator car (1) of claim 7, wherein the connection mechanism (11) is a scissor mechanism.
10. The elevator car (1) of claim 9, wherein the tension member (16a, 16b) passes through an intersection point (15a, 15b) of the scissor mechanism and connects to the support frame (8).
11. The elevator car (1) of claim 9, wherein the tension member (16a, 16b) is connected to an intersection point (15a, 15b) of the scissor mechanism.
12. An elevator system comprising an elevator car (1) according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Certain preferred examples of this disclosure will now be described, by way of example only, and with reference to the accompanying drawings, in which:
(2) FIGS. 1a, 1b and 1c are cutaway schematic views of an elevator car including a working platform, moveable between a stowed position (as shown in FIGS. 1a and 1b) and an operational position (as shown in FIG. 1c);
(3) FIG. 2 is a perspective view of a working platform according to an example of the present disclosure, in the operational position, in which the top surface of the working platform is visible;
(4) FIG. 3 is a perspective view of a working platform according to this example of the present disclosure, in the operational position, in which the underside of the working platform is visible;
(5) FIG. 4 is a plan view of the hoisting device according to this example of the present disclosure, when the working platform is in the operational position;
(6) FIG. 5 is a perspective view of a working platform according to this example of the present disclosure, in the stowed position, in which the top surface of the working platform is visible;
(7) FIG. 6 is a perspective view of a working platform according to this example of the present disclosure, in the stowed position, in which the underside of the working platform is visible;
(8) FIG. 7 is a plan view of the hoisting device according to this example of the present disclosure, when the working platform is in the stowed position;
(9) FIG. 8 is a partial perspective view of the underside of the working platform as the working platform is being moved between the operational position and the stowed position, by actuating the hoisting device; and
(10) FIG. 9 is a partial side view of the working platform, including the hoisting device and an actuator, as shown in FIG. 8.
DETAILED DESCRIPTION
(11) FIG. 1a shows a view of an elevator car 1, which defines an interior space 2. The elevator car 1 has side walls 4 surrounding the interior space 2. Above the interior space 2 there is a support frame 8, beneath which there is pivotably attached a decorative ceiling cover panel 10. In this arrangement, as shown in FIG. 1a, a passenger located within the interior space 2 of the elevator car 1, sees the decorative ceiling cover panel 10 as covering the vast majority, or even the entirety of the elevator car ceiling, such that the support frame 8 is not normally visible.
(12) FIG. 1b shows the elevator car 1 of FIG. 1a, in which the decorative ceiling cover panel 10 has been pivoted down to an open position. The elements of FIGS. 1b and 1c, which are already labelled in FIG. 1a, and can easily be identified as such by the skilled person, have not been labelled again in FIGS. 1b and 1c so as to improve the clarity of the drawings. Although FIG. 1b shows the decorative ceiling cover panel 10 as having been hinged open, from a pivot point in the elevator car ceiling, it is equally possible that the decorative ceiling cover panel 10 could be fixed in place by any other suitable mechanism, such as for example screws or clips, and could then be removed entirely from the ceiling of the elevator car 1 in order to expose the support frame 8.
(13) Once the decorative ceiling cover panel 10 has been pivoted down or removed, the working platform 12 is then visible, located within the support frame 8 above the interior space 2 of the elevator car 1. In the elevator car as shown in FIG. 1b, the working platform 12 is still in the stowed positon, but is now accessible such that a maintenance person can move the working platform 12 from the stowed position shown in FIG. 1b, to the operational position, as shown in FIG. 1c.
(14) As is most clearly seen in FIG. 1c, a connection mechanism 11 is arranged to suspendably connect the working platform 12 to the support frame 8. In this example, the connection mechanism 11 is a scissor mechanism. The scissor mechanism 11 opens out to allow the working platform 12 to be suspended within the interior space 2. The connection mechanism 11 can be any suitable mechanism which allows the working platform 12 to be moved between the stowed position and the operational position, and is able to adequately support the working platform 12 (together with any load carried in use) in its operational position.
(15) As shown in FIG. 1c, the working platform 12 can be lowered from the stowed position into the interior space 2 of the elevator car. This lowered position of the working platform 12 is referred to herein as the operational position. It is in this position that a maintenance person can use the working platform 12 to stand on, and thereby access parts of the elevator system through the open ceiling for maintenance purposes. The height of the working platform 12 in the operational position is ideally 1.0 m or 1.1 m below the support frame 8, such that a maintenance person standing fully upright on the working platform 12 will protrude out of an opening in the ceiling of the elevator car 1 as provided by the support frame 8. The working platform 12 has a top surface 13 (seen in FIG. 2) and an underside 14 (seen in FIG. 3).
(16) The connection mechanism 11 supports the working platform 12 in the operational position, and is able to bear the weight both of the working platform 12 and the weight of a maintenance person and any tools (up to a certain recommended maximum weight). In the absence of the hoisting device according to the present invention, a maintenance person would have to manually lower the working platform 12 from the stowed position, as shown in FIG. 1a, to the operational position, as shown in FIG. 1c. The connection mechanism 11 does not provide any resistance to this motion and so the maintenance person would need to support some of the weight of the working platform 12 as it was lowered, in order to prevent a sudden drop of the working platform 12 which would risk injury to the maintenance person and/or damage to the elevator car. In order to return the working platform 12 from the operational position to the stowed position, the maintenance person would have to push the working platform 12 upwards against its weight. However, the working platform 12 may weigh as much as 60 kg and so this can require the maintenance person to exert a large amount of upwards force, which is undesirable due to health and safety considerations.
(17) According to examples of the present disclosure there is provided a hoisting device, which, when actuated by a maintenance person, changes the length of a suspending portion of a tension member, thereby hoisting or lowering the working platform as required, and thus helping the maintenance person to move the working platform 12 between the operational and stowed positions, in a controlled manner and without having to support its weight.
(18) FIGS. 2 and 3 show a working platform 12 according to an example of the present disclosure. The working platform 12 is in the operational position. In FIG. 2 the top surface 13 of the working platform 12 is visible, in FIG. 3 the underside 14 of the working platform 12 is visible. In addition to the connection mechanism 11, the working platform 12 is also connected to the support frame 8 by a first tension member 16a and a second tension member 16b, although as described above, these tension members could be connected instead to an intersection point of the connection mechanism 11. The first tension member 16a is close to a first side of the working platform 12, and the second tension member 16b is close to a second, opposing side of the working platform 12. In this example, the first tension member 16a passes through the intersection point 15a, or apex, of the connection mechanism 11. The second tension member 16b passes through the intersection point 15b, or apex, of the connection mechanism 11. The working platform 12 includes a ladder 30, which a maintenance person can fold down in order to climb up onto the working platform 12.
(19) Each tension member 16a, 16b is connected to the support frame 8 at a first end of the respective tension member 16a, 16b. The second end of each tension member 16a, 16b is connected to a hoisting device 18 according to the present disclosure, as shown in FIG. 3. Each tension member 16a, 16b includes a suspending portion 17a, 17b between the support frame 8 and the working platform 12, which is suspending the working platform 12, or would be if it were not for the connection mechanism 11. In the example as shown, each suspending portion 17a, 17b is substantially vertical. The hoisting device 18 is shown in more detail in FIG. 4.
(20) FIG. 4 shows the arrangement of the hoisting device 18 when the working platform 12 is in the operational position, as shown in FIGS. 2 and 3. In this example, the hoisting device 18 includes a worm screw 20 and a sliding member 22. The mechanism of a worm screw is such that as the worm screw 20 is turned, by means of end connection 32, the sliding member 22 slides along the worm screw 20. The direction (left or right, as viewed in FIG. 4) in which the sliding member 22 moves is determined by the direction of rotation of the worm screw 20. By the meshing of the thread of the worm screw 20 and the corresponding worm gear within the sliding member 22, the rotational motion of the worm screw 20 is converted into longitudinal motion of the sliding member 22. The thread angle (pitch angle) and thread depth of the worm screw are chosen such that the worm screw is self-locking i.e. so that if a maintenance person stops turning the worm screw 20 then the worm screw 20 will remain stationary and so will the sliding member 22. Thus the working platform 12 will remain stationary as long as the worm screw is not turned i.e. actuated (unless of course, the working platform is moved by a different means e.g. manually lifted). This allows the working platform 12 to be raised or lowered to intermediate positions, and then held there without requiring effort from the maintenance person. Often a locking mechanism is included at the support frame 8, to allow the working platform 12 to be locked in the stowed position. However, using the hoisting device 18 of the present invention, the working platform 12 can be locked in the stowed position without use of such an additional locking mechanism, simply using the self-locking of the hoisting device.
(21) The sliding member 22 includes a hole which is configured to receive the worm screw and act as a worm-gear i.e. convert rotational motion of the worm screw into longitudinal motion of the sliding member 22 along the worm screw 20. The hole which receives the sliding member 22 is a plastic self-lubricating ring comprising grooves, which provide the worm-gear mechanism. This allows for easy movement of the sliding member 22 along the worm screw 20.
(22) The hoisting device 18 also includes a first elongate rod 26 and second elongate rod 28. The sliding member 22 is arranged to slide along these rods 26, 28 as it moves along the worm screw 20. These rods 26, 28 are smooth so that the sliding member 22 can slide smoothly along them, as it moves, but help to provide stability to the sliding member 22 and prevent it from twisting.
(23) The hoisting device 18 also includes a first deflection sheave 24a and a second deflection sheave 24b. As shown, when the working platform 12 is in the operational position, the sliding member 22 is close to a first end 34 of the worm screw, the end which is nearer to the first and second deflection sheaves 24a, 24b. The first end 34 is also nearer to the end connection 32. When the sliding member 22 is at this first end, very little of the tension members 16a, 16b, is passing back and forth between the respective deflection sheaves 24a, 24b and the sliding member 22, and therefore the remaining length of the tension members 16a, 16b i.e. the length of the suspending portion 17a, 17b (not shown in FIG. 4) which is suspending the working platform, is long.
(24) The hoisting device 18 furthermore includes a third deflection sheave 36a and a fourth deflection shave 36b. These deflection sheaves 36a, 36b direct the tension members 16a, 16b towards the outer edges of the working platform 12, to intersection points 38a, 38b. At these intersection points, the respective tension members 16a, 16b pass through the working platform 12. The portion of each tension member 16a, 16b which is the other side of the intersection point 38a, 38b (not shown) is the suspending portion 17a, 17b.
(25) FIGS. 5 and 6 show the working platform 12 according to the present disclosure, in the stowed position. In FIG. 5 the top surface 13 of the working platform 12 is visible, in FIG. 6 the underside 14 of the working platform 12 is visible.
(26) FIG. 7 shows the arrangement of the hoisting device 18 when the working platform 12 is in the stowed position, as shown in FIGS. 5 and 6. The same components are labelled as in FIG. 4. As shown, when the working platform 12 is in the stowed position, the sliding member 22 is close to a second end 36 of the worm screw 20, the end which is further from the first and second deflection sheaves 24a, 24b. Thus, the tension members 16a, 16b pass around their respective deflection sheaves 24a, 24b, and pass back and forth between these deflection sheaves 24a, 24b and the sliding member 22. In the example as shown, the roping arrangement is 3:1, such that each tension member 16a, 16b passes back and forth between the deflecting sheave 24a, 24b and the sliding member 22 three times. This means that the length of the suspending portion of the tension member 17a, 17b (not shown in FIG. 7) will have been reduced by three times the length of the distance between the respective deflection sheave 24a, 24b and the sliding member 22. Thus, in the stowed position as shown in FIG. 7, a large length of each tension member 16a, 16b is ‘gathered’ between the sliding member 22 and the deflection sheaves 24a, 24b, meaning that the suspending portion 17a, 17b of the tension member 16a, 16b is very short.
(27) FIG. 8 is a perspective view of the underside 14 of the working platform 12 as the working platform 12 is being moved between the operational position and the stowed position. The working platform 12 is being moved by actuation of the hoisting device 18. The hoisting device 18, specifically the end connection 32, is being rotationally driven using a crank 40. A crank is often provided as a standard tool within an elevator car. However, the crank 40 could instead be replaced by an electric drill, which requires minimal exertion from a maintenance person in order to actuate the hoisting device 18.
(28) FIG. 9 is a side view of the working platform 12, as shown in FIG. 8, including the hoisting device 18 and the crank 40. The hoisting device 18 includes a bracket 42 arranged to limit the angle α at which the crank 40 extends. As shown, the crank 40 extends from the end connection 32 at an angle of a, where a is between approximately 120° and 150°. This helps to protect the technician from harm.
(29) Although the embodiments described above include a hoisting device in the form of a worm screw, it will be appreciated that this mechanism could be replaced by another type of linear drive or any other device that can be operated to change the length of the tension members. For example, a gas spring or reduction gear assembly might be employed instead.
(30) It will be appreciated by those skilled in the art that the disclosure has been illustrated by describing one or more specific examples thereof, but is not limited to these aspects; many variations and modifications are possible, within the scope of the accompanying claims.
