Elevator assembly with counterweight blocking stop

Abstract

An elevator assembly (1) comprises an elevator car (2), a counterweight (4), and a safety device (8) located on a roof (9) of the elevator car (2). A locking handle (10) is positioned within the elevator shaft (6), and connected to a first end (12a) of a tension member (12). A blocking stop (14) is connected to a second end (12b) of the tension member (12). The blocking stop (14) is moveable between an inactive state, in which the tension member (12) holds the blocking stop (14) in a position in which it does not limit downwards movement of the counterweight (4), and an active state, in which tension in the tension member (12) is reduced to allow the blocking stop (14) to move to a position in which it limits downwards movement of the counterweight (4).

Claims

1. An elevator assembly (1), comprising: an elevator car (2) arranged to move in an elevator shaft (6); a counterweight (4) coupled to the elevator car (2) and arranged to move upwards and downwards in the elevator shaft (6); a safety device (8) located on a roof (9) of the elevator car (2) and moveable between a deployed position, in which it extends away from the roof (9) of the elevator car (2), and an undeployed position in which it is stowed on the roof (9) of the elevator car; a locking handle (10) positioned within the elevator shaft (6), and connected to a first end (12a) of a tension member (12; 212a, 212b); a blocking stop (14; 214a, 214b), which is connected to a second end (12b) of the tension member (12; 212a, 212b), and which is moveable between an inactive state, in which the tension member (12; 212a, 212b) holds the blocking stop (14; 214a, 214b) in a position in which it does not limit downwards movement of the counterweight (4), and an active state, in which tension in the tension member (12; 212a, 212b) is reduced to allow the blocking stop (14; 214a, 214b) to move to a position in which it limits downwards movement of the counterweight (4); and a safety switch (11) arranged such that, when the safety device (8) is in the deployed position, the safety switch (11) is triggered and thereby causes the locking handle (10) to move so as to reduce tension in the tension member (12; 212a, 212b), thereby allowing the blocking stop (14; 214a, 214b) to move into the active state.

2. The elevator assembly (1) of claim 1, wherein the locking handle (10) further comprises a locking member (10a) arranged to hold the locking handle (10) in a first position that puts the tension member (12; 212a, 212b) under tension so as to hold the blocking stop (14; 214a, 214b) in the inactive state.

3. The elevator assembly (1) of claim 2, wherein the locking handle (10) further comprises an electromagnetic actuator (10d) arranged to release the locking member (10a) when the safety switch (11) is triggered, so that the locking handle (10) can move to a second position to reduce tension in the tension member (12; 212a, 212b), thereby allowing the blocking stop (14; 214a, 214b) to move into the active state.

4. The elevator assembly (1) of claim 1, wherein the locking handle (10) comprises a rotary member (10c) connected to the first end (12a) of the tension member (12; 212a, 212b) and a handle member (10b) arranged to turn the rotary member (10c) and thereby adjust tension in the tension member (12; 212a, 212b).

5. The elevator assembly (1) of claim 1, further comprising at least one visual indicator (18) of the blocking stop (14; 214a, 214b) being in the active or inactive state.

6. The elevator assembly (1) of claim 5, wherein the visual indicator is a traffic light system (18) comprising a first light indicating that the blocking stop (14; 214a, 214b) is in the active state and a second light indicating that the blocking stop (14; 214a, 214b) is in the inactive state.

7. The elevator assembly (1) of claim 5, wherein the visual indicator (18) is electrically connected to the blocking stop (14; 214a, 214b).

8. The elevator assembly (1) of claim 1, comprising at least one resilient member (26a, 26b) connected to the blocking stop (14; 214a, 214b).

9. The elevator assembly (1) of claim 8, wherein the at least one resilient member (26a, 26b) is arranged to be extended when the blocking stop (14; 214a, 214b) is moved to the inactive state by the tension member (12; 212a, 212b).

10. The elevator assembly (1) of claim 8, wherein the at least one resilient member (26a, 26b) is arranged to relax when the tension is reduced and help the tension member (12; 212a, 212b) to move the blocking stop (14; 214a, 214b) to the active state.

11. The elevator assembly (1) of claim 1, wherein the blocking stop (14; 214a, 214b) is arranged to rotate into the active state.

12. The elevator assembly (1) of claim 1, wherein the blocking stop (14; 214a, 214b) is mounted on a counterweight guide rail (16; 16a, 16b).

13. The elevator assembly (1) of claim 1, comprising a first blocking stop (214a) connected to a first tension member (212a) and a second blocking stop (214b) connected to a second tension member (212b), wherein the first and second tension members (212a, 212b) are connected to the locking handle (10).

14. The elevator assembly of claim 13, wherein the first and second blocking stops (214a, 214b) are electrically connected in series to a or the visual indicator (18).

15. An elevator system comprising the elevator assembly (1) of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Certain exemplary embodiments of this disclosure will now be described with reference to the accompanying drawings, in which:

(2) FIG. 1 schematically illustrates an example elevator assembly according to the prior art;

(3) FIG. 2 schematically illustrates an example elevator assembly according to an example of the present invention;

(4) FIG. 3a is a close-up view of an exemplary locking handle;

(5) FIG. 3b schematically illustrates the arrangement of a tension member in the interior of the locking handle of FIG. 3a;

(6) FIG. 4 schematically illustrates a plan view of an exemplary layout of an elevator assembly according to the present disclosure;

(7) FIG. 5a schematically illustrates an example with two blocking stops in an inactive state;

(8) FIG. 5b schematically illustrates an example with two blocking stops in an active state; and

(9) FIG. 6 is a schematic block flow diagram representing some functional connections between some components in an exemplary elevator assembly.

DETAILED DESCRIPTION

(10) FIG. 1 schematically illustrates selected portions of an elevator assembly 80 as known from the prior art. The elevator assembly 80 includes an elevator car 82 coupled to a counterweight 84 located within an elevator shaft 86. A safety device 88 is located on the roof of the elevator car 82. The safety device 88 can be deployed to provide a barrier function as shown in FIG. 1.

(11) A blocking stop 81 is located in the pit of the elevator shaft 86, and is arranged to move, responsive to the safety device 88 being deployed, between a retracted position and a deployed position, in which it limits the movement of the counterweight 84 in a downward direction. In this way, movement of the elevator car 82 in an upward direction can be limited, allowing a maintenance person 85 to safely enter the elevator shaft 86 and work from the roof of the elevator car 82. The position of the blocking stop 81 can additionally be indicated by a visual indicator 83.

(12) FIG. 2 schematically illustrates selected portions of an elevator assembly 1 according to the present invention, that includes an elevator car 2 and a counterweight 4 located within an elevator shaft 6. The counterweight 4 is coupled to the elevator car 2 in any suitable manner, as defined by the prior art, for example using roping or belts (not shown) so as to move upwards and downwards in the elevator shaft 6 in response to movement of the elevator car 2.

(13) The elevator assembly 1 further includes a locking handle 10 positioned within the elevator shaft 6. The locking handle 10 may be mounted on a wall of the elevator shaft 6 at such a position that it can be reached by a service technician 22 from the uppermost landing 20 when the elevator car 2 has been stopped for a maintenance procedure. The locking handle 10 includes a locking member 10a and handle member 10b.

(14) When the elevator car 2 has been stopped for a maintenance procedure, it is desirable to prevent any upwards movement of the elevator car 2 by blocking downwards movement of the counterweight 4. This is achieved by activating one or more blocking stops 14, for example a blocking stop 14 seen in FIG. 2 positioned in a pit of the elevator shaft 6.

(15) The locking handle 10 is coupled to the blocking stop 14 by a tension member 12, for example via a pulley 26 or other equivalent system for guiding the tension member 12. The tension member 12 may be a cable in some examples. As is more clearly seen in FIGS. 3a and 3b, the locking handle 10 is connected to a first end 12a of the tension member 12 by virtue of the tension member 12 being at least partially wrapped around a rotary member 10c (such as a drum). The tension member 12 is fixed in place to the locking handle 10 by a locking clamp 10e, as seen in FIG. 3b, which shows the arrangement of the tension member 12 in the interior of the locking handle 10.

(16) With reference to FIG. 3a, the locking handle 10 is seen to include the rotary member 10c, a handle member 10b that can be grasped to turn the rotary member 10c, a locking member 10a and an associated electromagnetic actuator 10d. The locking member 10a is activated, e.g. when a current is applied to the electromagnetic actuator 10d, to hold the locking handle 10 in a first position (seen in FIG. 3a) that puts the tension member 12 under tension (i.e. the inactive state of the blocking stop 14). The electromagnetic actuator 10d is electrically connected to a safety switch, as will be described in more detail below. When the locking member 10a is released, e.g. by disconnecting the current to the electromagnetic actuator 10d, the locking handle 10 is free to move to a second position to reduce tension in the tension member 12 (i.e. the active state of the blocking stop 14). The motion of the locking handle may be aided by the use of a pneumatic piston 10f attached to the rotary member 10c.

(17) In this example, the locking handle 10 moves in a rotary fashion. When the locking member 10a is released, the rotary member 10c is free to turn clockwise from a first (vertical) position (seen in FIGS. 3a and 3b), pulled by the tension member 12 so as to reduce tension in the tension member 12. This turns the handle member 10b from the first (vertical) position to the second (horizontal) position seen in phantom in FIG. 2. To return the locking handle 10 from the second position to the first position, the rotary member 10c can be manually rotated in reverse (i.e. anti-clockwise) by turning the handle member 10b back to the first (vertical) position shown in FIGS. 3a and 3b. This wraps more of the first end 12a of the tension member 12 around the rotary member 10c, increasing the tension and causing the tension member 12 to pull the blocking stop 14 back into the inactive state. Upon reaching the first position, the locking member 10a is re-activated (e.g. by activating the electromagnetic actuator 10d using another switch triggered by movement of the locking handle 10) to hold the locking handle 10 in the first position and hence hold the blocking stop 14 in the inactive state.

(18) Returning to FIG. 2, it will be appreciated that, when the blocking stop 14 is held in the inactive state by tension in the tension member 12, the blocking stop 14 is not limiting downwards movement of the counterweight 4. A visual indicator 18 may display a warning (e.g. red) light. In this mode of operation, the elevator car 2 and the counterweight 4 may move close to the top and bottom of the elevator shaft 6 respectively. When the blocking stop 14 is in the active state, the counterweight 4 is prevented from moving to the bottom of the elevator shaft 6, preventing the elevator car 2 from moving to the top of the elevator shaft 6. This results in a space above the elevator car 2 being made available, allowing maintenance or inspection procedures to be safely carried out.

(19) In this example, the counterweight 4 and the blocking stop 14 are located on a counterweight guide rail 16 located in the elevator shaft 6. However, in practice, the blocking stop 14 could instead be mounted on a wall 7 of the elevator shaft 6 or in any other suitable configuration close to the operational range of movement of the counterweight 4.

(20) The elevator assembly 1 shown in FIG. 2 further includes a safety device 8 located on a roof 9 of the elevator car 2, that can be selectively moved between a deployed position and an undeployed position by an operator such as a service technician 22. In the deployed position shown in FIG. 2, the safety device 8 is positioned such that it extends away from the roof 9 of the elevator car 2, forming a physical safety barrier at the edge of the elevator car 2. The relative positions of the safety device 8 (when undeployed), the locking handle 10 and the elevator car 2 in the elevator shaft 6 are shown in FIG. 4.

(21) During normal operation of the elevator car 2, the safety device 8 is stowed on the roof 9 of the elevator car in an undeployed position (seen in phantom in FIG. 2), such that the elevator car 2 may travel to the top of its operational range. In at least some examples, the safety device 8 is connected to the roof 9 of the elevator car 2 by, for example, a hinge, allowing it to be folded up from, and down to, the roof 9 of the elevator car to minimise its profile when not in use.

(22) In certain situations, such as in the event that a maintenance procedure must be carried out, it is necessary to maintain a safe operating area above the elevator car 2 within the elevator shaft 6 to allow sufficient space for, e.g. a service technician 22 to have access to the roof 9 of the elevator car 2. In such situations, the safety device 8 is manually moved into the deployed position by, e.g. a service technician 22. In some examples, the safety device 8 is accessible from the landing 20 such that it can be moved into the deployed position without entry into the elevator shaft 6.

(23) The elevator assembly 1 includes a safety switch 11 (such as a position switch) which is triggered when the safety device 8 is moved into the deployed position, causing the locking member 10a of the locking handle 10 to release, and allowing the locking handle 10 to move into the second position in which the tension in the tension member 12 is reduced, allowing the blocking stop 14 to move into an active state in which it limits the downwards motion of the counterweight 4. This movement of the locking handle 10 provides a first visual indication of whether or not the blocking stop 14 is active, which can be confirmed from the state of the visual indicator 18, from which it can be determined whether it is safe for a service technician 22 to enter the elevator shaft 6.

(24) When a service technician 22 has finished a maintenance operation, he/she may leave the elevator shaft 6 and stow away the safety device 8. The locking handle 10 can then be manually operated from the landing 20. Moving the locking handle 10 in a reverse direction pulls the blocking stop 14 into an inactive position via the tension member 12, and allows the elevator car 2 and the counterweight 4 to return to a normal range of operation. As discussed above, the locking member 10a is activated to hold the blocking stop 14 in the inactive state via the tension member 12.

(25) FIG. 4 shows the general layout of some components of the elevator assembly in the elevator shaft 6. The counterweight 4 is guided by counterweight rails 16a, 16b to run alongside the elevator car 2. The locking handle 10 is mounted to a wall of the elevator shaft 6 in a position that can be reached by a person wishing to enter from the landing 20. The safety device 8 is mounted on the roof 9 of the elevator car 2. The safety device 8 has two pivot points 8a, 8b so that the safety device 8 can be pivoted down from its deployed position to an undeployed position in which it is stowed flat on the roof 9. It can be seen that there is only a small distance d between the safety device 8 and the landing 20.

(26) In this example, the elevator assembly 1 further includes a visual indicator 18, mounted on the roof 9 of the elevator car 2, which shows whether the blocking stop 14 is in the active state or inactive state, and hence provides further indication of whether it is safe for a service technician 22 to enter the elevator shaft 6. The visual indicator 18 is, for example, a traffic light system with two lights, e.g. a green light illuminated when the blocking stop 14 is in the active state and a red light illuminated when the blocking stop 14 is in the inactive state.

(27) FIGS. 5a and 5b represent a particular example, in which the counterweight 4 is mounted on a pair of counterweight guide rails 16a, 16b, with two blocking stops, 214a and 214b, each located on one of the counterweight guide rails 16a, 16b. The two blocking stops 214a, 214b are operably connected to the locking handle 10 by two tension members 212a and 212b respectively. The tension members 212a and 212b may be diverted from the locking handle 10 to the blocking stops 214a, 214b by a system of deflection sheaves, such that the two tension members 212a, 212b are connected in parallel to the locking handle 10.

(28) FIGS. 5a and 5b also show two resilient members 26a and 26b in the form of spring coils. The resilient members 26a, 26b are employed such that they are extended when the blocking stops 214a, 214b are in the inactive state, i.e. when the tension members 212a, 212b are held under sufficient tension, as shown in FIG. 5a. In this manner, when the locking handle is moved to reduce the tension in the tension members 212a, 212b, the resilient members 26a, 26b relax, helping to forcibly move the blocking stops 214a, 214b into the active state, shown in FIG. 5b. When the locking handle 10 is moved in the reverse direction, increasing the tension in the tension members 212a, 212b, the resilient members 26a, 26b are extended, and the blocking stops 214a, 214b pulled into and held in the inactive state by the tension members 212a, 212b. The resilient members 26a, 26b can be held in the extended state until they are subsequently released when the position of the locking handle 10 is moved, for example, during the next maintenance operation.

(29) As shown schematically in FIGS. 5a and 5b, each of the blocking stops 214a, 214b is operatively connected to a position switch 34, 36. The function of these switches 34, 36 is described below with reference to FIG. 6. The first and second blocking stops 214a, 214b are electrically connected in series to the visual indicator 18 via these position switches 34, 36.

(30) FIG. 6 shows a schematic block flow diagram representing the activation of the blocking stops 214a, 214b in the example shown in FIGS. 5a and 5b, as would take place during, for example, a maintenance operation. A service technician 22 first moves the safety device 8 into the deployed position, which should trigger the safety switch 11 at step 71. The triggering of the switch 11 activates the electromagnetic actuator 10d in the locking handle 10, releasing the locking member 10a (step 72) and allowing the locking handle 10 to turn from its first position to its second position, reducing the tension in the tension members 212a, 212b. This should result in the blocking stops 214a, 214b moving to the active state in which downwards movement of the counterweight 4 is limited, and providing a safe space above the elevator car 2 for the service technician 22 to enter the elevator shaft 6 (steps 73, 74). If the locking handle 10 is not seen to turn to its second position, and no change is seen in the state of the visual indicator 18, then the service technician 22 will realise that the blocking stops 214a, 214b have not been moved correctly into the active state.

(31) Furthermore, the visual indicator 18 is designed to confirm to the service technician 22 that it is safe to enter the elevator shaft 6, in which case the visual indicator 18 may display a green light, shown in block 75. Alternatively, a red light is displayed, as shown in block 76, indicating that it is potentially unsafe to enter the elevator shaft 6. In order to detect that the blocking stops 214a, 214b have correctly moved into the active state, the two blocking stops 214a, 214b move into contact with switches 34 and 36 respectively. The switches 34 and 36 are connected to the green light in series, such that if either of the switches 34, 36 is not triggered, i.e. in the event that one of the blocking stops 214a, 214b has not moved into the active state, the green light is not illuminated, and instead the red light is illuminated. Of course, any other colours or types of indicator may be implemented in the visual indicator 18.

(32) 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 examples; many variations and modifications are possible, within the scope of the accompanying claims.