|
(11) | EP 1 464 606 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
|
|
|
|
||||||||||||||||
| (54) | ELEVATOR |
| (57) An elevator system including a hoist disposed on the top portion of a hoistway, a
wire rope wound around a traction sheave of the hoist and provided with an elevator
car at its one end and a counter weight at the other end, a compensation chain having
respective ends fastened to the lower portion of the elevator car and the lower portion
of the counter weight, a relief weight connectable to the compensation chain in emergencies
for adjusting the balance between the elevator car and the counter weight to cause
the elevator car to move, and detecting means for detecting that the relief weight
is connected to the compensation chain. |
TECHNICAL FIELD
[0001] This invention relates to an elevator system and, particularly, to a safe method for restoring from an emergency mode to a normal mode in elevators having no machine room.
BACKGROUND ART
[0002] Examples of a known elevator system are disclosed in Japanese Patents Laid-Open Nos. 2000-351548 and 2000-169055, and one of such examples is shown in Figure 3. Figure 3 is a sectional view of a conventional elevator system showing the structure thereof.
[0003] In Figure 3, 1 is an elevator car. 2 is a counter weight (CWT). 3 is a compensation chain. 4 is a relief weight. 5 is a hoist, and it is disposed on the top of the hoistway. 6 is a brake releasing apparatus.
[0004] The elevator car 1 and the CWT 2 described above are connected to either end of the wire rope wound around the hoist 5. The compensation chain 3 is disposed such that the both ends thereof locate separately under the elevator car 1 or the CWT 2. The relief weight 4 is connected to the compensation chain 3 in cases such as necessitating rescues in emergencies, and adjusts the balance between the elevator car 1 weight and the CWT 2. The brake releasing apparatus 6 disposed on the hoist 5 releases the brake of the hoist 5. The brake releasing apparatus 6 of the hoist 5 is operated by remote control at the side of the landing or the like on the uppermost floor.
[0005] The operation in emergencies of the conventional elevator system shown in Figure 3 is described in the following.
[0006] If the elevator car 1 suspends halfway between floors due to power failure or the like, for instance, elevator passengers in such emergencies are generally rescued by making the car 1 alight on the nearest floor using the brake releasing apparatus 6 to let the passengers get off the car. The brake releasing apparatus 6 allows the brake of the hoist 5 to be manually released to cause the elevator car 1 to move upward or downward due to the unbalance between the elevator car 1 weight and the CWT 2. It is not possible to make the elevator car 1 move, however, if the weight of the elevator car 1 and the CWT 2 is balanced (in such cases as where the elevator car 1 is accommodating half the nominal riding capacity), even if the brake is released, and so in such cases the relief weight 4 is mounted to the compensation chain 3 disposed under the elevator car 1 for adjusting the balance between the elevator car 1 weight and the CWT 2 and causing an unbalance therebetween and letting the elevator car 1 move.
[0007] Thus, conventional elevator systems have a problem that relief weights, if left unremoved, could fall on and hit elevator machinery and tools to damage them after restoration to a normal driving following rescuing of elevator passengers.
DISCLOSURE OF INVENTION
[0008] The present invention, that has been made to solve the problem described above, has as its object to provide an elevator system in which restoration to a normal driving with the relief weight unintentionally failed to dismount is restrained.
[0009] In order to achieve the above object, an elevator system according to the invention comprises a hoist disposed on the top portion of a hoistway, a wire rope wound around a traction sheave of the hoist and provided with an elevator car at its one end and a counter weight at the other end, a compensation chain having respective ends fastened to the lower portion of the elevator car and the lower portion of the counter weight, a relief weight connectable to the compensation chain in emergencies for adjusting the balance between the elevator car and the counter weight to cause the elevator car to move, and detecting means for detecting that the relief weight is connected to the compensation chain.
[0010] Also, acccording to the elevator system of the present invention, the driving of the elevator car may be suspended when said detecting means detects that the relief weight is connected to said compensation chain.
[0011] Also, according to the elevator system of the present invention, the detecting means may comprise a light switch, which detects that the relief weight is connected to the compensation chain when the relief weight interrupts the beam of light between a light emitting section and a light receiving section of the light switch.
[0012] Further, in the elevator system of the present invention, the detecting means may be disposed at either the lower portion of the elevator car or the lower portion of the counter weight, and the operation of the elevator car is suspended when it detects the load of the relief weight.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
Figure 1 is a sectional view of an elevator system of exemplary embodiment 1 of the invention showing the structure thereof;
Figure 2 is an enlarged view of the compositions under the elevator car in an elevator system of exemplary embodiment 2 of the invention; and
Figure 3 is a sectional view of a conventional elevator system showing the structure thereof.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1.
[0015] An elevator system of one exemplary embodiment of the invention will now be described while referring to Figure 1. Figure 1 is a sectional view of an elevator system of Embodiment 1 of the invention showing the structure thereof.
[0016] In Figure 1, 7 is a light switch or a detecting means that is disposed at the bottom of the hoistway, and detects whether or not something has passed based on the occurrence or not of the interruption of beams of light running between the light emitting section and the light receiving section thereof opposing each other. An attempt to restore to a normal driving with a relief weight 4 remained connected to a compensation chain 3 fails because an omission to remove the relief weight 4 is revealed through the interruption of the beams of light of the light switch 7 by the relief weight 4 connected to the compensation chain 3, and this induces the suspension of the movement of an elevator car 1, thus preventing restoration to a normal driving.
[0017] In Figure 1, those components that are common in the example of a conventional elevator system shown in Figure 3 or those the counterparts thereof are found in Figure 3 are given the same reference numerals with no explanation, and the component that is not found in Figure 3 is given a new reference numeral.
[0018] Thus, it is possible to prevent the occurrence of a situation in which the relief weight 4 falls down on and hit the elevator machinery and tools to damage them because restoration to a normal driving with the relief weight 4 left unremoved is not possible as the light switch 7 disposed at the bottom of the hoistway detects whether or not the relief weight 4 is connected to the compensation chain 3 and whether or not the elevator system can be restored to a normal driving through the occurrence or not of the interruption of the beams of light running between the light emitting section and the light receiving section of the light switch 7.
[0019] Further, it is possible to prevent the occurrence of undesirable phenomenon of generating a slip between the wire rope and the hoist sheave due to insufficient friction therebetween that could happen when the elevator is operated with the car accommodating full passengers, for example, because of the unbalance between the elevator car 1 and the CWT 2 as a consequence of the presence of the relief weight 4 when the elevator system is restored to a normal driving by omitting the removal of the relief weight 4.
Embodiment 2.
[0020] The elevator system of another exemplary embodiment of the present invention will now be described with reference to Figure 2. Figure 2 is an enlarged view of an elevator system of Embodiment 2 of the invention showing the composition under the elevator car.
[0021] In Figure 2, 9 is a beam onto which one end of the compensation chain 3 is fastened. One end of the beam 9 is arranged to be rotatable about a pin 8 under the elevator car. 10 is a spring, and it supports the beam 9 at the other end to bear the weight of the compensation chain 3. 11 is a switch, and it restrains the elevator system's normal driving when the beam 9 serving as an operation lever is pulled downward. The operation lever is pulled downward when the spring 10 is compressed under the loads of the compensation chain 3 and the relief weights 4 mounted thereto.
[0022] Thus, when the switch 11 is turned on upon the downward movement of the operation lever, it is determined that the relief weights 4 are mounted on the compensation chain 3 and the restoration of the elevator operation to a normal driving mode is prevented when the relief weights 4 are unintentionally failed to be dismounted.
[0023] Although the integral components are disposed at the lower portion of the elevator car 1 in this embodiment, such the components may equally be disposed at the lower portion of the CWT 2.
[0024] As has been described, an elevator system according to the invention comprises a hoist disposed on the top portion of a hoistway, a wire rope wound around a traction sheave of the hoist and provided with an elevator car at its one end and a counter weight at the other end, a compensation chain having respective ends fastened to the lower portion of the elevator car and the lower portion of the counter weight, a relief weight connectable to the compensation chain in emergencies for adjusting the balance between the elevator car and the counter weight to cause the elevator car to move, and detecting means for detecting that the relief weight is connected to the compensation chain, so that it is possible to prevent the relief weight from falling down on and hit the elevator machinery and tools to damage them as a consequence of unintentional failure to remove the relief weight when restoring to a normal operation.
INDUSTRIAL APPLICABILITY
1. An elevator system comprising:
a hoist disposed on the top portion of a hoistway;
a wire rope wound around a traction sheave of said hoist and is provided with an elevator car at one end thereof and a counter weight at the other end thereof;
a compensation chain having respective end thereof fastened to the lower portion of the elevator car and the lower portion of the counter weight;
a relief weight connectable to said compensation chain in emergencies for adjusting the balance between the elevator car and the counter weight to cause the elevator car to move; and
detecting means for detecting that said relief weight is connected to said compensation chain.
2. An elevator system as claimed in claim 1 wherein the driving of the elevator car is
suspended when said detecting means detects that the relief weight is connected to
said compensation chain.
3. An elevator system as claimed in claim 2 wherein said detecting means comprises a
light switch, which detects that the relief weight is connected to the compensation
chain when the relief weight interrupts the beam of light between a light emitting
section and a light receiving section of the light switch.
4. An elevator system as claimed in claim 1 wherein said detecting means is disposed
at either the lower portion of the elevator car or the lower portion of the counter
weight, and the operation of the elevator car is suspended when it detects the load
of the relief weight.