Abstract
An elevator car defining an interior space for accommodating passengers and/or cargo, comprising a support frame positioned above the interior space, a working platform moveable between a stowed position, above the interior space, and an operational position, within the interior space and at least one extendable suspension arrangement arranged to suspend the working platform from the support frame. The extendable suspension arrangement includes a connection plate, a first arm member connected at a first end to the support frame and slidably connected to a first connection point of the connection plate and a second arm member connected at another first end to the working platform and slidably connected to a second connection point of the connection plate.
Claims
1. An elevator car (1) defining an interior space (2) for accommodating passengers and/or cargo, the elevator car (1) comprising: a support frame (4) positioned above the interior space (2); a working platform (6) moveable between a stowed position, above the interior space (2), and an operational position, within the interior space (2); and at least one extendable suspension arrangement (8a, 8b) arranged to suspend the working platform (6) from the support frame (4), the extendable suspension arrangement (8a, 8b) comprising: a connection plate (10a, 10b, 10c, 10d); a first arm member (12a, 12b, 12c, 12d) connected at a first end (3a, 3b, 3c, 3d) to the support frame (4) and slidably connected to a first connection point (16a, 16b, 16c, 16d) of the connection plate (10a, 10b, 10c, 10d); a second arm member (14a, 14b, 14c, 14d) connected at another first end (5a, 5b, 5c, 5d) to the working platform (6) and slidably connected to a second connection point (18a, 18b, 18c, 18d) of the connection plate (10a, 10b, 10c, 10d); wherein the first arm member (12a, 12b, 12c, 12d) and the second arm member (14a, 14b, 14c, 14d) are configured to slide parallel to each other, along a sliding direction (13a), in order to extend the extendable suspension arrangement (8a, 8b) when the working platform (6) moves between the stowed position and the operational position, and wherein the first connection point (16a, 16b, 16c, 16d) and the second connection point (18a, 18b, 18c, 18d) have an offset (17a) from one another across the connection plate at least in a direction perpendicular to the sliding direction (13a).
2. The elevator car (1) of claim 1, wherein the first connection point (16a, 16b, 16c, 16d) and the second connection point (18a, 18b, 18c, 18d) additionally have another offset (19a) from one another along the sliding direction (13a).
3. The elevator car (1) of claim 1, wherein the connection plate (10a, 10b, 10c, 10d) comprises a pivot point (28a, 28b, 28c, 28d) arranged such that the connection plate (10a, 10b, 10c, 10d) rotates about the pivot point (28a, 28b, 28c, 28d) when the working platform (6) moves between the stowed position and the operational position.
4. The elevator car (1) of claim 1, wherein the first connection point (16a, 16b, 16c, 16d) comprises a first projection and wherein the first arm member (12a, 12b, 12c, 12d) comprises a slot (20a, 20b), and the first projection is configured to slide in the slot.
5. The elevator car (1) of claim 4, wherein the slot (20a, 20b) extends along substantially the entire length of the first arm member (12a, 12b, 12c, 12d).
6. The elevator car (1) of claim 4, wherein the connection plate (10a, 10b, 10c, 10d) comprises a second projection (24a, 24b), wherein the second projection (24a, 24b) is also configured to slide in the slot (20a, 20b) of the first arm member (12a, 12b, 12c, 12d).
7. The elevator car (1) of claim 1, comprising a first extendable suspension arrangement (8a) and a second extendable suspension arrangement (8b), wherein the first extendable suspension arrangement (8a) suspends the working platform (6) from a first side of the support frame (4), and wherein the second extendable suspension arrangement (8b) suspends the working platform (6) from a second, opposing side of the support frame (4).
8. The elevator car (1) of claim 1, wherein the first extendable suspension arrangement (8a, 8b) further comprises: a secondary connection plate (10b, 10c); a secondary first arm member (12b, 12c) connected at a first end (3b, 3c) to the support frame (4) and slidably connected to a first connection point (16b, 16c) of the secondary connection plate (10b, 10c); a secondary second arm member (14b, 14c) connected at a first end (5b, 5c) to the working platform and slidably connected to a second connection point (18b, 18c) of the secondary connection plate (10b, 10c); wherein the first arm member and the second arm member are configured to slide parallel to each other, along a sliding direction, and wherein the first connection point (16b, 16c) and the second connection point (18b, 18c) are offset from one another at least in a direction perpendicular to the sliding; wherein the first connection plate (10a, 10d) and the secondary connection plate (10b, 10c) are attached together at their respective pivot points (28a, 28b, 28c, 28d), so as to be movable relative to each other.
9. The elevator car (1) of claim 8, wherein the counterforce generator comprises at least one deflector (130, 132, 154, 224a, 224b, 236a, 236b) such as a deflection sheave, and the tension member is arranged to pass over the at least one deflector, and wherein the tension member is arranged in a roping ratio of at least 2:1 with the hoisting device.
10. The elevator car (1) of claim 1, further comprising a counterforce generator (120, 140, 218) configured to provide a counterforce; and a tension member (124, 216a, 216b), connected to the working platform (6) and to the counterforce generator (120, 140, 218), so as to transmit the counterforce and thereby hoist the working platform (6) from the operational position to the stowed position.
11. The elevator car (1) of claim 10, wherein the counterforce generator (120, 140, 218) is a hoisting device; and wherein the tension member (124, 216a, 216b) is arranged such that a suspending portion (217a, 217b) of the tension member suspends the working platform (6), wherein the hoisting device is configured, when actuated, to alter the length of the suspending portion (217a, 217b), so as to hoist the working platform between the stowed position and the operational position.
12. The elevator car (1) of claim 10, wherein the counterforce generator comprises at least one spring element (140) and the spring element is arranged to be compressed as the working platform (6) is moved from the stowed position to the operational position, and thereby provide the counterforce acting to move the working platform (6) from the operational position to the stowed position.
13. The elevator car (1) of claim 10, wherein the counterforce generator comprises at least one counterweight (120) and the tension member (124) is fixed at one end to the at least one counterweight (120) and connected to the working platform (6) such that, as the at least one counterweight (120) moves downwards vertically relative to the elevator car (1), the working platform (6) is hoisted in from the operational position to the stowed position.
14. The elevator car (1) of claim 10, wherein the counterforce generator (218) is a worm screw.
15. An elevator system (101) comprising an elevator car (1) according to claim 1, further comprising a main counterweight (105) and one or more ropes or belts (107) connected between the elevator car (1) and the main counterweight.
Description
DRAWING DESCRIPTION
(1) Certain preferred examples of this disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:
(2) FIG. 1 shows a cutaway view of an elevator car including an extendable suspension arrangement for a working platform, according to a first aspect of the present disclosure;
(3) FIG. 2 shows a side view of the working platform, extendable suspension arrangement, and support frame of the elevator car of FIG. 1, with the working platform in an operational position;
(4) FIG. 3 shows a perspective view of the elevator car components shown in FIG. 2, with the working platform moving between a stowed position and the operational position;
(5) FIG. 4 shows a side view of the elevator car components shown in FIG. 2, with the working platform in the stowed position;
(6) FIG. 5 shows a detailed side view of the extendable suspension arrangement, including a connection plate and first and second arm members, according to the first aspect of the present disclosure;
(7) FIG. 6a shows a blown-apart view of the components shown in FIG. 5;
(8) FIG. 6b shows a connection plate as seen in FIGS. 5 and 6a;
(9) FIG. 7 shows a perspective view of some components of an elevator car and a counterforce generator according to a first example of a second aspect of the present disclosure, with the working platform in a stowed position;
(10) FIG. 8 shows the same components as FIG. 7, with the working platform moving between the stowed position and an operational position;
(11) FIG. 9 shows the same components as FIGS. 7 and 8, with the working platform in the operational position;
(12) FIG. 10 is a close-up view showing how the counterforce generator is connected to the working platform by a tension member in this first example;
(13) FIG. 11 is another close-up view of the counterforce generator in this first example;
(14) FIG. 12 shows an underside perspective view of some components of an elevator car and a counterforce generator according to a second example of the second aspect of the present disclosure, with the working platform in a stowed position;
(15) FIG. 13 shows the same components as FIG. 12, with the working platform moving between the stowed position and an operational position;
(16) FIG. 14 shows the same components as FIGS. 12 and 13, with the working platform in the operational position;
(17) FIG. 15 is close-up view showing how the counterforce generator is connected to the working platform by a tension member in this second example;
(18) FIG. 16 is a perspective view of a working platform according to a third example of the second aspect of the present disclosure, in an operational position, in which the top surface of the working platform is visible;
(19) FIG. 17 is a perspective view of the working platform according to this third example, in the operational position, in which a hoisting device is visible on the underside of the working platform;
(20) FIG. 18 is a plan view of the hoisting device according to this third example of the present disclosure, when the working platform is in the operational position;
(21) FIG. 19 is a perspective view of the working platform according to this third example of the present disclosure, in the stowed position, in which the top surface of the working platform is visible;
(22) FIG. 20 is a perspective view of the working platform according to this third example of the present disclosure, in the stowed position, in which the underside of the working platform is visible;
(23) FIG. 21 is a plan view of the hoisting device according to this third example of the present disclosure, when the working platform is in the stowed position;
(24) FIG. 22 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 according to this third example;
(25) FIG. 23 is a partial side view of the working platform, including the hoisting device and an actuator, as shown in FIG. 22; and
(26) FIG. 24 is a schematic illustration of an elevator system according to various examples of the present disclosure.
DETAILED DESCRIPTION
(27) FIG. 1 shows an elevator car 1 which defines an interior space 2, which is suitable for accommodating passengers and/or cargo. The elevator car 1 includes a support frame 4 which is positioned above the interior space 2. The elevator car 1 also includes a working platform 6, which is moveable between a stowed position (as shown in FIG. 4), above the interior space 2, and an operational position, within the interior space 2, as is seen in FIG. 1. The working platform 6 is suspended by a first extendable suspension arrangement 8a and a second extendable suspension arrangement 8b, which, as shown, are on opposite sides of the elevator car 1 and opposite sides of the working platform 6.
(28) As seen in FIGS. 1-6, each extendable suspension arrangement 8a, 8b includes two connection plates 10a, 10b, 10c, 10d. One of the connection plates 10b, 10c is on the inner side of the suspension arrangements 8a, 8b i.e. closer to the working platform 6, and the other connection plate 10a, 10d is on the outer side of the extendable suspension arrangement i.e. further from the working platform 6. Each connection plate 10a, 10b, 10c, 10d is slidably connected at a respective first connection point 16a, 16b, 16c, 16d to a respective first arm member 12a, 12b, 12c, 12d. Each first arm member 12a, 12b, 12c, 12d is connected at a first end 3a, 3b, 3c, 3d to the support frame 4. Similarly, each connection plate 10a, 10b, 10c, 10d is slidably connected at a respective second connection point 18a, 18b, 18c, 18d to a respective second arm member 14a, 14b, 14c, 14d. Each second arm member 14a, 14b, 14c, 14d is connected at another first end (i.e. a first end of the second arm member) 5a, 5b, 5c, 5d to the working platform 6.
(29) A side view of some of the elevator car components, showing the extendable suspension arrangement 8a, but omitting the outer structure of the elevator car 1, is shown in FIG. 2. The features described herein with reference to the extendable suspension arrangement 8a apply likewise to extendable suspension arrangement 8b, although the corresponding reference numerals have been omitted. It will be understood from FIG. 1 that the pair of suspension arrangements 8a, 8b (on the left and right) are arranged to suspend the working platform 6 from the support frame 4 in the operational position seen in FIG. 2.
(30) As can be seen in FIG. 2, each of the first arm members 12a, 12b comprises a slot 20a, 20b and each of the second arm members 14a, 14b comprises a slot 22a, 22b. Each slot 20a, 20b, 22a, 22b extends along substantially the entire length of the first arm member 12a, 12b and the second arm member 14a, 14b respectively. Each connection plate 10a, 10b includes a first projection 16a, 16b (providing a first connection point) and a second projection 24a, 24b both configured to slide in the slots 20a, 20b of the first arm members 12a, 12b. Similarly, each connection plate 10a, 10b includes another first projection 18a, 18b (providing a second connection point), and another second projection 26a, 26b and both configured to slide in the slots 22a, 22b of the second arm members 14a, 14b. Thus the respective first projections 16a, 18a and second projections 24a, 26a of the first and second arm members 12a, 14a define a sliding direction along which the first arm member 12a and the second arm member 14a are arranged to slide. This sliding direction can be seen in FIG. 6b and is described in more detail below. In a similar way, the respective first projections 16b, 18b and second projections 24b, 26b of the first and second arm members 12b, 14b define a sliding direction along which the first arm member 12b and the second arm member 14b are arranged to slide.
(31) Each connection plate 10a, 10b comprises a pivot point 28a, 28b. The first connection plate 10a and the second connection plate 10b of the extendable suspension arrangement 8a (and similarly the extendable suspension arrangement 8b) are attached together at their respective pivot points 28a, 28b so as to rotate relative to each other about this shared pivot point 28a, 28b. As can be seen, the pivot point 28a, 28b is located centrally between the first connection point 16a, 16b and the second connection point 18a, 18b, both along the sliding direction, and perpendicular to the sliding direction. As the first connection plate 10a rotates relative to the second connection plate 10b, the sliding directions of each corresponding set of first and second arm members 12a, 12b, 14a, 14b likewise rotate about the shared pivot point 28a, 28b. This can be appreciated by comparing FIGS. 2 and 3.
(32) The elevator car 1 optionally further includes a cover panel 30, which is configured to cover the working platform 6 when the working platform 6 is in the stowed position, as shown in FIG. 4.
(33) As the working platform 6 is moved between the operational position (seen in FIG. 2) and the stowed position (seen in FIG. 4), the first connection plate 10a, 10d and second connection plate 10b, 10c rotate relative to each other i.e. in opposite directions (and thus the sliding directions of the pairs of arms also rotate relative to each other). At the same time, the first arm member 12a, 12b, 12c, 12d and the second arm member 14a, 14b, 14c, 14d slide parallel to each other, along a sliding direction, as can be seen with reference to FIGS. 2, 3 and 4, which show the stages as the working platform 6 moves from the operational position to the stowed position. The sliding direction is fixed relative to the connection plate, as described with reference to the later Figures, but as the connection plate rotates, so too does the sliding direction. As can be seen in the side view of FIG. 2, the first connection point 16a, 16b and the second connection point 18a, 18b have an offset from one another in a direction perpendicular to the sliding direction. In the example shown, the first connection point 16a, 16b and the second connection point 18a, 18b also have an offset from one another along the sliding direction. These offsets are described in more detail below, with reference to FIG. 6b.
(34) By connecting the first and second arm members 12a, 12b, 14a, 14b slidably to the connection plates 10a, 10b, 10c, 10d with an offset between the first and second connection points 16a, 16b, 18a, 18b, an extendable suspension arrangement 8a is provided which has both a long range of extension between the stowed and operational positions, and also a compact footprint when not extended.
(35) When the working platform 6 is in the operational position, as shown in FIG. 2, a second end 7a of the first arm member 12a is pulled away from a second end 9a of the second arm member 14a, providing a long range of extension for the the extendable suspension arrangement 8a, thereby allowing the working platform 6 to be lowered to a desired height within the interior space 2 of the elevator car 1.
(36) As the working platform 6 is moved from the operational position (seen in FIG. 2) to the stowed position (seen in FIG. 4) the first arm member 12a, 12b, 12c, 12d and the second arm member 14a, 14b, 14c, 14d slide relative to the connection plate 10a, 10b, 10c, 10d, as seen in FIG. 3, and the connection plates 10a, 10b rotate in opposite directions about the shared pivot point 28a, 28b.
(37) When the working platform 6 is in the stowed position, as shown in FIG. 4, the first end 3a of the first arm member 12a, 12b is adjacent to the second end 9a of the second arm member 14a, 14b and the first end 5a of the second arm member 12a, 12b is adjacent to the second end 7a of the second arm member 14a, 14b. As seen in FIG. 4, due to the offset along the sliding direction of the first and second connection points 16a, 18a, 24a, 26a, the first arm member and the second arm member 12a, 14a slide into a “stacked” position, in which they overlap along the sliding direction 13a. Furthermore, due to the pivoting of the connection plates 10a, 10b, the first and second arm members 12a, 14a rotate (whilst sliding) to sit in a substantially horizontal position (as defined relative to the elevator car 2) above the working platform 6 in the stowed position, as seen in FIG. 4.
(38) The arrangement of the connection plates 10a, 10b and first and second arm members 12a, 12b, 14a, 14b is shown in more detail in the view of FIG. 5, and in the exploded view of FIG. 6a. FIG. 6b shows a single exemplary connection plate 10a. Throughout this description, each reference numeral is followed by either “a” or “b”. These reference numerals refer to like components, with the additional “a” and “b” indicating that this component is part of the first extendable suspension arrangement 8a, respectively the outer and inner parts of the first extendable suspension arrangement 8a. Likewise, although not included in FIGS. 2-6, the statements made herein apply likewise to the components of the second extendable suspension arrangement 8b seen in FIG. 1, respectively the inner and outer parts of the second extendable suspension arrangement 8b, labelled elsewhere with “c” and “d”. The terms “a” and “b”, are used in the following description for clarity, but it will be understood by the skilled person that these statements may apply likewise to the second extendable suspension arrangement 8b having components followed by “c” and “d”.
(39) As shown, the exemplary extendable suspension arrangement 8a includes a first arm member 12a, 12b, having a slot 20a, 20b, and a second arm member 14a, 14b, having a second slot 22a, 22b. Each connection plate 10a, 10b comprises four projections, 16a, 16b, 18a, 18b, 24a, 24b, 26a, 26b. The projections 16b, 18b, 24b and 26b are visible only from their rear side in the view shown in FIG. 5, and project from the side of the connection plate 10b which is not seen in FIG. 5 i.e. into the page. There are a first projection 16a, 16b and a second projection 24a, 24b arranged to move in the slot 20a, 20b of the first arm member 12a, 12b, to form a sliding connection. There are similarly a first projection 18a, 18b and a second projection 26a, 26b, arranged to move in the slot 22a, 22b of the second arm member 14a, 14b, to form a sliding connection. For a given extendable suspension arrangement 8a there is a first set including a connection plate 10a, a first arm member 12a, a second arm member 14a, and there is then a second set including a connection plate 10b, a first arm member 12b and a second arm member 14b (and likewise for “c” and “d”). The connection plates 10a, 10b of these “sets” each have a central pivot point 28a, 28b about which the connection plates 10a, 10b rotate as the extendable suspension arrangement 8a extends when the working platform 6 moves between the stowed position and the operational position. The connection plates 10a, 10b of the extendable suspension arrangement 8a are arranged to rotate in opposite directions to one another. The connection plates 10a, 10b are joined at these pivot points 28a, 28b to form a kind of scissor mechanism.
(40) These two “sets” are shown more clearly in a blown-apart view in FIG. 6a. The reference numerals followed by “a” and “b” have been used as an example, but this applies equally to the components “c” and “d”. It can be seen that each of the projections 16a, 18a, 24a, 26a is formed by an arrangement of a nut and bolt, placed on opposing sides of the slots 20a, 20b, 22a, 22b and fastened together, in this example. Each projection 16a, 18a, 24a, 26a additionally includes two washers, to improve the smoothness of sliding. Additionally it can be seen that the pivot points 28a, 28b are attached together by a nut and bolt, passing through a respective hole on each plate 10a, 10b. Washers are again included, to assist in smooth rotation. Of course, other examples could omit such a nut and bolt fastening and instead rely on projections formed on the surfaces of the connection plates 10a, 10b to slide in the slots 20a, 20b, 22a, 22b, or a combination of these two approaches could be used.
(41) The first projection 16a forms a first connection point which is fixed relative to the connection plate 10a. The first projection 16a together with the second projection 24a defines a sliding direction 13a for the first arm member 12a. Similarly the first projection 18a forms a second connection point which is also fixed relative to the connection plate 10a, and together the first and second projections 18a, 26a define a sliding direction 13a for the second arm member 14a, which is parallel to the sliding direction 13a of the first arm member 12a. This ensures that the first arm member 12a and the second arm member 14a do not converge as they slide.
(42) The sliding direction 13a is seen more clearly in FIG. 6b, which shows a single connection plate 10a (although this could equally be one of the other connection plates 10b, 10c, or 10d). The first arm member and the second arm member (not shown) slide along the parallel sliding directions 13a. As seen in FIG. 6b, the first projection 16a, forming the first connection point, and the second projection 18a, which forms the second connection point, are offset from each other by a total offset 15a.
(43) The total offset 15a is made up of two different components. There is a first offset component 17a, which is an offset along a direction that is perpendicular to the sliding direction 13a of the first and second arm members. The offset 17a along this direction allows the first and second arm members to slide along their lengths without contacting each other. There is also a second offset component 19a, which is an offset along the sliding directions 13a. The offset 19a along the sliding directions 13a increases the total length of the extendable suspension arrangement when both the first arm member and the second arm member are fully “extended” i.e. slid as far as possible away from each other.
(44) The first and second connection points 16a, 18a are fixed relative to the connection plate 10a, so the sliding direction 13a is constant with respect to the connection plate 10a. However, as described above, the connection plate 10a is arranged to pivot around the pivot point 28a as the extendable suspension arrangement extends or contracts, so that as the working platform is moved between the stowed and operational positions, the connection plate 10a rotates. Therefore, during this movement, the sliding direction 13a itself rotates with respect to the frame of reference of the elevator car 1.
(45) As described above, in some examples, the elevator car further comprises a counterforce generator, configured to provide a counterforce acting against the weight of the working platform, and a tension member.
(46) In a first set of examples, as shown in FIGS. 7-11, the counterforce generator comprises a set of counterweights 120. FIG. 7 shows the elevator car 1 according to the present disclosure, in which the decorative ceiling cover panel 30 has been pivoted down, but the working platform 6 is still in the stowed position. The counterweights 120 are shown as each being arranged in a vertical stack and retained within a surrounding structure 122 (such as a tube). The surrounding structure 122 retains the counterweights 120 in position to move along a fixed vertical path, and ensures that they do not fall into the hoistway which could pose a danger. However, there could be no surrounding structure, or a different shape of structure to that shown. Additionally there could be any number of counterweights, for example a single counterweight. In some examples there is at least one counterweight, or a set of counterweights, on each of two opposing sides of the working platform 6. This advantageously provides increased stability and a more symmetrically balanced counterforce to the working platform 6.
(47) When the working platform 6 is in the stowed position, as shown in FIG. 7, the counterweights 120 are at their lowest position, at the bottom of the surrounding structure 122, close to the floor 121 of the elevator car. The side walls of the car have been omitted for clarity. As the working platform 6 is moved out of the stowed position and away from the support frame 4, down towards the operational position, as shown in FIG. 8, the counterweights 120 begin to move vertically upwards, i.e. away from the car floor 121. The working platform 6 shown in FIG. 8 is suspendably connected to the support frame 4 by suspension arrangements 8a, 8b, shown here schematically (omitting the detail which is seen in FIGS. 1-6).
(48) Once the working platform 6 is in the operational position, as shown in FIG. 9, the counterweights 120 are at their uppermost position within the surrounding structure 122. The suspension arrangements 8a, 8b are also shown schematically in FIG. 9.
(49) The working platform 6 is connected to each of the counterweights 120 by a tension member 124, in this example a rope, as seen most clearly in FIG. 10. One end of the tension member 124 is fixed to the working platform 6 at a first connection point 126, and the other end of the tension member 124 is connected to one of the counterweights 120 at a second connection point 128. Between the first connection point 126 and the second connection point 128, the tension member 124 passes over a first deflection sheave 130 and over a second deflection sheave 132. Any number of such deflection sheaves can be used, as required. The first deflection sheave 130 converts vertical motion of the working platform 6 into horizontal motion of a section of the tension member 124, and the second deflection sheave 132 converts this horizontal motion of the section of tension member into vertical motion of the section of tension member 124, connected to the counterweight 120.
(50) Thus, the weight of the counterweights 120 generates a counterforce that is transmitted by the tension member 124 and acts to apply an upwards vertical force to hoist the working platform 6 towards the stowed position. In some examples, the weight of the counterweights 120 provides a counterforce approximately equal to the force acting downwards on the working platform due to its weight. In some examples, the weight of the counterweights 120 provides a counterforce which is slightly larger than the downwards force acting on the working platform 6 due to its weight. As a result of this, absent any additional forces, the working platform 6 is automatically hoisted to the stowed position. When a maintenance person moves the working platform 6 from the stowed position to the operational position, he or she must then place an additional weight, for example a toolbox, or apply their own weight, to keep the working platform 6 in the operational position. Alternatively, or in addition, there may be a mechanism for holding the working platform 6 in the operational position. Additionally shown in FIG. 10 is the extendable suspension arrangement 8a shown in the previous Figures.
(51) The arrangement of the counterweights 120 in the surrounding structures 122 is shown in more detail in FIG. 11. Each surrounding structure 122, in this example a tube, is adjacent to, and optionally fixed or attached to, a car upright 136. Car uprights 136 are existing components known in the art, and various numbers and arrangements of car upright are possible in accordance with the present disclosure. The number and placement of counterweights 120 and surrounding structures 122 can be altered depending on the number and arrangements of car uprights 136. Each surrounding structure 122 additionally includes a stopper 138 at the bottom of the surrounding structure 122, which prevents the counterweights 120 from falling out of the bottom of the surrounding structure 122, possibly into the hoistway which could create a danger (e.g. in the event of there being a fault with the tension member 124, or a counterweight 120 becoming detached).
(52) In the example seen in FIG. 10, the tension member 124 is fixed at one end to the counterweight 120 and fixed at its other end to the working platform 6, i.e. a 1:1 roping. However, it will be appreciated that other roping ratios may be used instead, for example the tension member 124 could be arranged to undersling the working platform 6 with its other end fixed to a suitable connection point in the car (e.g. on the opposite upright 136 or on the support frame 4).
(53) A second example is shown in FIGS. 12-15. In this example, the counterforce generator comprises a spring element 140, in particular a gas spring. This is advantageous because gas springs are more reliable than coil springs. In the particular example shown, the spring element 140 is attached to the working platform 6, specifically to the underside of the working platform 6. The spring element 140 could alternatively be attached to a top or side surface of the working platform 12, but when attached to the underside the spring element 140 is less likely to get in the way of a maintenance person using the working platform 6. Alternatively, the spring element 140 may be attached to another suitable component of the elevator car 1, such as the support frame 4 or other stationary part of the elevator car ceiling. In FIG. 12, the working platform 6 is shown in the stowed position, with the decorative ceiling cover panel 30 in the open position. It can be seen that the spring element 140 has a piston 152 which is in a fully extended position and thus there is zero counterforce.
(54) As the working platform 6 is moved down between the stowed position and the operational position, as shown in FIG. 13, the spring element 140 is partially compressed. FIG. 14 shows the working platform 6 in the operational position. In this position, as shown, the spring element 140 is fully compressed.
(55) As shown in FIGS. 12, 13 and 14, the piston 152 of the spring element 140 is connected to a tension member 124, which could, for example, be a rope. In the particular example shown, the tension member 124 also passes through a deflection plate 150 that is fixed to the working platform 6, before then passing through an aperture 154 in the working platform 6. The number of times that the tension member 124 passes back and forth between the deflection plate 150 and the piston 152 can be adjusted to give a gearing effect as horizontal movement of the piston 152 is translated into vertical movement of the tension member 124. Any other suitable roping arrangement, which results in the spring element 140 being compressed as the working platform 6 is moved from the stowed position to the operational position, is possible in accordance with the present disclosure.
(56) FIG. 15 shows how the tension member 124 passes through the aperture 154 in the working platform and extends vertically to be connected at its second end to a connection point 156 in the elevator car 1 that moves relative to the working platform 6, as the working platform 6 is moved from the stowed position to the operational position. In this example, the point 156 is a pivot point of the extendable suspension arrangement 8b that controls movement of the working platform 6 relative to the support frame 4. The suspension arrangements 8a, 8b are as described with reference to the earlier Figures. Connecting the tension member 124 to the pivot point of the extendable suspension arrangement 8b advantageously allows the stroke of the spring element 140 to be reduced and consequently is particularly well suited for small elevator cars. The second end of the tension member 124 could alternatively be connected to a fixed point in the elevator car 1, such as a car floor or ceiling. In another set of examples, the second end of the tension member 124 is connected to the pivot point of the extendable suspension arrangement 8b and the first end of the tension member 124 is connected to a spring element 140 that is attached to the support frame 4 or other part of the car ceiling, rather than being attached to the working platform 6.
(57) Although, in this example, the first end of the tension member 124 is connected to a spring element 140 which is attached to the working platform 6, with the second end attached to a point 156 which moves relative to the working platform 6 as the working platform 6 is moved down in the elevator car 1, alternatively, the spring element 140 could be attached to a fixed structure within the elevator car 1, and the second end of the tension member 124 could be connected to the working platform 6. For example, the spring element 140 could be attached to the support frame 4 or elsewhere above the ceiling of the elevator car 1. This would still provide compression of the spring element 140, and hence a counterforce, as the working platform 6 is moved from the stowed position to the operational position, and the tension member 124 could still be arranged to hoist the working platform 6 in the upwards vertical direction.
(58) As a result of the arrangement described above, the spring element 140 provides a counterforce as the working platform 6 is moved downwards into the operational position, due to the compression of the spring element 140. This damping effect can make it safer for a maintenance person to handle the working platform 6. Then, once the working platform 6 is in the operational position, this counterforce is transmitted by the tension member 124, to hoist the working platform 6 back towards the stowed position. In some examples, the counterforce provided by the spring element 140 could be less than or approximately equal to the downward force acting on the working platform 6 due to its weight, so that once moved to the operational position it tends to stay there. In other examples, the counterforce provided by the spring element 140 may be larger than the downward force acting on the working platform 6 due to its weight, such that once moved to the operational position, the working platform 6 will tend to move back upwards to the stowed position unless an additional weight, such as a toolbox, or a maintenance person, is placed on the working platform 6.
(59) In yet other examples, as shown in FIGS. 16-23, the counterforce generator is 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 6 between the operational and stowed positions, in a controlled manner and without having to support its weight.
(60) FIGS. 16 and 17 show a working platform 6 according to an example of the present disclosure. The working platform 6 is in the operational position. In FIG. 16 the top surface 213 of the working platform 6 is visible, in FIG. 17 the underside 214 of the working platform 6 is visible. In addition to the suspension arrangements 8a, 8b (which are shown schematically, omitting some of the detail shown in the earlier Figures) the working platform 6 is also connected to the support frame 4 by a first tension member 216a and a second tension member 216b, although as described above, these tension members could be connected instead to an intersection point of the suspension arrangements 8a, 8b. The first tension member 216a is close to a first side of the working platform 6, and the second tension member 216b is close to a second, opposing side of the working platform 6. In this example, the first tension member 216a passes through the intersection point 215a, or apex, of the extendable suspension arrangement 8a. The second tension member 16b passes through the intersection point 15b, or apex, of the extendable suspension arrangement 8b. The working platform 6 includes a ladder 230, which a maintenance person can fold down in order to climb up onto the working platform 6.
(61) Each tension member 216a, 216b is connected to the support frame 4 at a first end of the respective tension member 216a, 216b. The second end of each tension member 216a, 216b is connected to a hoisting device 218 according to the present disclosure, as shown in FIG. 17. Each tension member 216a, 216b includes a suspending portion 217a, 217b between the support frame 4 and the working platform 6, which is suspending the working platform 6, or would be if it were not for the suspension arrangements 8a, 8b. In the example as shown, each suspending portion 217a, 217b is substantially vertical. The hoisting device 218 is shown in more detail in FIG. 18.
(62) FIG. 18 shows the arrangement of the hoisting device 218 when the working platform 6 is in the operational position, as shown in FIGS. 16 and 17. In this example, the hoisting device 218 includes a worm screw 220 and a sliding member 222. The mechanism of a worm screw is such that as the worm screw 220 is turned, by means of end connection 232, the sliding member 222 slides along the worm screw 220. The direction (up or down, as viewed in FIG. 18) in which the sliding member 222 moves is determined by the direction of rotation of the worm screw 220. By the meshing of the thread of the worm screw 220 and the corresponding worm gear within the sliding member 222, the rotational motion of the worm screw 220 is converted into longitudinal motion of the sliding member 222. 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 220 then the worm screw 220 will remain stationary and so will the sliding member 222. Thus the working platform 6 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 6 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 4, to allow the working platform 6 to be locked in the stowed position. However, using the hoisting device 218 of the present invention, the working platform 6 can be locked in the stowed position without use of such an additional locking mechanism, simply using the self-locking of the hoisting device.
(63) The sliding member 222 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 222 along the worm screw 220. The hole which receives the sliding member 222 is a plastic self-lubricating ring comprising grooves, which provide the worm-gear mechanism. This allows for easy movement of the sliding member 222 along the worm screw 220.
(64) The hoisting device 218 also includes a first elongate rod 226 and second elongate rod 228. The sliding member 222 is arranged to slide along these rods 226, 228 as it moves along the worm screw 220. These rods 226, 228 are smooth so that the sliding member 222 can slide smoothly along them, as it moves, but help to provide stability to the sliding member 222 and prevent it from twisting.
(65) The hoisting device 218 also includes a first deflection sheave 224a and a second deflection sheave 224b. As shown, when the working platform 6 is in the operational position, the sliding member 222 is close to a first end 234 of the worm screw, the end which is nearer to the first and second deflection sheaves 224a, 224b. The first end 234 is also nearer to the end connection 232. When the sliding member 222 is at this first end, very little of the tension members 216a, 216b, is passing back and forth between the respective deflection sheaves 224a, 224b and the sliding member 222, and therefore the remaining length of the tension members 216a, 216b i.e. the length of the suspending portion 217a, 217b (not shown in FIG. 18) which is suspending the working platform, is long.
(66) The hoisting device 218 furthermore includes a third deflection sheave 236a and a fourth deflection shave 236b. These deflection sheaves 236a, 236b direct the tension members 216a, 216b towards the outer edges of the working platform 6, to intersection points 238a, 238b. At these intersection points, the respective tension members 216a, 216b pass through the working platform 6. The portion of each tension member 216a, 216b which is the other side of the intersection point 238a, 238b (not shown) is the suspending portion 217a, 217b.
(67) FIGS. 19 and 20 show the working platform 6 according to the present disclosure, in the stowed position. In FIG. 19 the top surface 213 of the working platform 6 is visible, in FIG. 20 the underside 214 of the working platform 6 is visible.
(68) FIG. 21 shows the arrangement of the hoisting device 218 when the working platform 6 is in the stowed position, as shown in FIGS. 19 and 20. The same components are labelled as in FIG. 18. As shown, when the working platform 6 is in the stowed position, the sliding member 222 is close to a second end 236 of the worm screw 220, the end which is further from the first and second deflection sheaves 224a, 224b. Thus, the tension members 216a, 216b pass around their respective deflection sheaves 224a, 224b, and pass back and forth between these deflection sheaves 224a, 224b and the sliding member 222. In the example as shown, the roping arrangement is 3:1, such that each tension member 216a, 216b passes back and forth between the deflecting sheave 224a, 224b and the sliding member 222 three times. This means that the length of the suspending portion of the tension member 217a, 217b (not shown in FIG. 21) will have been reduced by three times the length of the distance between the respective deflection sheave 224a, 224b and the sliding member 222. Thus, in the stowed position as shown in FIG. 21, a large length of each tension member 216a, 216b is ‘gathered’ between the sliding member 222 and the deflection sheaves 224a, 224b, meaning that the suspending portion 217a, 217b of the tension member 216a, 216b is very short.
(69) FIG. 22 is a perspective view of the underside 214 of the working platform 6 as the working platform 6 is being moved between the operational position and the stowed position. The working platform 6 is being moved by actuation of the hoisting device 218. The hoisting device 218, specifically the end connection 232, is being rotationally driven using a crank 240. A crank is often provided as a standard tool within an elevator car. However, the crank 240 could instead be replaced by an electric drill, which requires minimal exertion from a maintenance person in order to actuate the hoisting device 218.
(70) FIG. 23 is a side view of the working platform 6, as shown in FIG. 22, including the hoisting device 218 and the crank 240. The hoisting device 218 includes a bracket 242 arranged to limit the angle α at which the crank 240 extends. As shown, the crank 240 extends from the end connection 232 at an angle of α, where α is between approximately 120° and 150°. This helps to protect the technician from harm.
(71) Although the examples described above in relation to FIGS. 16-23 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.
(72) As shown in FIGS. 1, 9 and 14-15, in all of the examples described above the working platform 6, 12, can be lowered from the stowed position into the interior space 2 of the elevator car to an operational position. The height of the operational position is determine by the range of movement of the extendable suspension arrangement. It is in this operational position that a maintenance person can use the working platform 6, 12 to stand on, and thereby access parts of the elevator system through the open ceiling for maintenance purposes. In particular, the height of the working platform 6, 12 in the operational position is ideally 1.0 m or 1.1 m below the support frame 4, 8. This means that a maintenance person standing fully upright on the working platform 8, 12 will protrude out of an opening in the ceiling of the elevator car 1 as provided by the support frame 4, 8. Furthermore, providing a minimum distance of 1.0 or 1.1 m between the working platform 6, 12 and the support frame, in the operational position, means that a maintenance person can take refuge in a safety space defined in the interior of the car in an emergency. The examples of an extendable suspension arrangement as disclosed herein provide a sufficient range of movement even when the car dimensions are small and a compact arrangement is needed in the stowed position.
(73) FIG. 24 is a perspective view of an elevator system 101 including a hoistway 117. An elevator car 1, according to the present disclosure, and a main counterweight 105 move in a vertical direction along the hoistway 117. There is seen an elevator car 1, a main counterweight 105, a set of one or more ropes and/or belts 107, a guide rail 109, a machine 111, a position reference system 113, and a controller 115. The elevator car 1 and main counterweight 105 are connected to each other by the set of ropes/belts 107s. The main counterweight 105 is configured to balance a load of the elevator car 1 and is configured to facilitate movement of the elevator car 1 concurrently and in an opposite direction with respect to the main counterweight 105 within an elevator hoistway 117 and along the guide rail 109.
(74) The ropes and/or belts 107 engage the machine 111, which is part of an overhead structure of the elevator system 101. The machine 111 is configured to control movement between the elevator car 1 and the main counterweight 105. The position reference system 113 may be mounted on a fixed part at the top of the elevator hoistway 117, such as on a support or guide rail, and may be configured to provide position signals related to a position of the elevator car 1 within the elevator hoistway 117.
(75) The controller 115 is located, as shown, in a controller room 123 of the elevator hoistway 117 and is configured to control the operation of the elevator system 101, and particularly the elevator car 1. For example, the controller 115 may provide drive signals to the machine 111 to control the acceleration, deceleration, levelling, stopping, etc. of the elevator car. The controller 115 may also be configured to receive position signals from the position reference system 113 or any other desired position reference device. When moving up or down within the elevator hoistway 117 along guide rail 109, the elevator car 1 may stop at one or more sets of landing doors 125 as controlled by the controller 115. Furthermore, the controller 115 may be used to drive the elevator car 1 to any position in the hoistway 117 where a maintenance person seeks sight of or access to components in the hoistway 117. Once the elevator car is safely held at such a position, a maintenance person riding in the car may deploy the working platform as already described above. Although shown in a controller room 123, those of skill in the art will appreciate that the controller 115 can be located and/or configured in other locations or positions within the elevator system 101.
(76) In one or more examples of the present disclosure, the elevator car 1 has relatively small dimensions, for example a car depth of 800 mm and a car width of 800 mm.
(77) It will be appreciated by those skilled in the art that the disclosure has been illustrated by describing one or more specific aspects thereof, but is not limited to these aspects; many variations and modifications are possible, within the scope of the accompanying claims.
