Procedure for checking the straightness of elevator guide rails and straightening the rails, and an apparatus set for performing the procedure

Abstract: The invention relates to a procedure for checking the straightness of elevator guide rails (11) and straightening deflections of the rails, an apparatus for implementing the procedure and to a measuring apparatus. The elevator guide rails (11) are inspected by means of a measuring device (1) movable along the rail (11), said device comprising two guides (5,6) placed successively along the guide rail (11) and leaning against the rail (11) as their stop face, by measuring the distance of the guide rail (11) between the guides (5,6) by means of the measuring device (1). The deflections detected are straightened and the straightened areas are checked by means of the measuring device (1).

Description: The present invention relates to a procedure for checking the straightness of elevator guide rails and straightening their deflections, and to an apparatus set for implementing the procedure. In fast high-quality elevators, a good travelling comfort is a target of increasing importance. Lateral swing, i.e. horizontal vibration of the passenger cabin of the elevator, is the predominant parameter of travelling comfort, and its quality is a significant argument in discussions relating to the travelling comfort provided by an elevator. Lateral swing may arise from several causes, but the primary cause are short, sharp bends in the guide rail line. The task of straightening these bends is generally the more difficult the longer the line is. On the other hand, long guide rail lines are generally used with faster elevators, and increased speed again means that the effect of bends in producing lateral swing becomes more pronounced. The need to minimize lateral swing is greatest in the case of top-quality elevators, tall buildings and especially elevators serving the top floors of the building. These elevators travel through long distances along the guide rails at a high speed. Therefore, to achieve the required low level of lateral swing, the guide rail line must be very straight. The equipment currently used for checking the straightness of the alignment of elevator guide rails, controlling the quality of guide rail lines and charting the lines and the lateral deflections in them requires special instrumentation and is quite bulky and complex, and rendering the results obtained into a form usable for the straightening of deflections requires subsequent calculations by means of computers. Such a solution, which is technically very demanding, may be acceptable in research and product development, but it is not very practical or efficient when new guide rail lines are to be installed or old ones improved. The means used at the sites of installation to check the straightness of the line are often of a rather coarse nature, e.g. comparing to a ruler or plumb line. Even visual estimates of the line quality have been resorted to. Thus, the estimates of line quality made in connection with installation have not been unambiguous but have been dependent on the experience and skill of the estimator. As the repeatability of the measurement is low, it is generally not possible to obtain sufficiently reliable estimates of the quality of the corrections made. Since the quality and straightness of the alignment of elevator guide rail lines may vary considerably from rail to rail and in different parts of the shaft, it must be possible to inspect complete guide rail lines easily and reliably. Similarly, it must be possible to control the quality of corrections to guide rail lines as accurately as possible even during the execution of the corrections. FR-A-2 436 366 discloses a mechanical measuring device for checking the straightness of railways, said measuring device being movable along the railway and comprising two guides which are placed successively along the railway and held in contact with the railway. The measuring device is provided with a measuring element which follows the railway surface and measures the distance of the railway from the measuring device. No means for straightening deflections have been disclosed. Another measuring device for detecting deformations on guide rails has been described in DE-A-39 13 159, said measuring device using an electronic reporting device. JP-A-53-142746 discloses the use of a measuring device which is mounted on an elevator cabin frame. To provide a solution to the problem referred to above, the present invention proposes a procedure and an apparatus set for checking the straightness of elevator guide rails and straightening their deflections. The procedure of the invention is characterized by what is presented in claim 1, the apparatus set of the invention is characterized by what is presented in claim 4. The other embodiments of the invention are characterized by what is presented in the other claims. The advantages achieved by the invention include the following: The procedure of the invention is easy to apply, the actions required by the procedure are well adapted as part of the installation operations, and the apparatus is robust enough to be handled in the circumstances prevailing in an elevator shaft. The apparatus can be used at the site of installation to chart the whole guide rail line and the problematic points in it by means of a recorder, allowing work to be concentrated on them. This enables savings to be achieved in the costs of both inspection and straightening of the rails. A better quality of guide rail installation is achieved as the deflections can be measured and also the required corrections are correct to the required accuracy and can be checked immediately. Easy to use, because the persons who installed the guide rails can perform the final quality inspection using the same equipment which was used in the installation work. Applicable for both new installations and modernization projects. The criteria of quality do not vary depending on the inspector's skill or working condition or on other factors. Permanent documentation of the inspection is easily obtained. In the following, the invention is described in detail by the aid of an example by referring to the drawings attached, in which Fig. 1a, 1b and 1c are diagrams representing some common types of deviation occurring at the joints between rails. Fig. 1d presents the cross-section of the guide rail Fig. 2 presents the measuring device Fig. 3a and 3b illustrate the straightening of deflections like those in Fig. 1a and 1b Fig. 4 presents a straightening device Fig. 5 illustrates the straightening of a rail joint by means of the straightening device, and Fig. 6a and 6b present guide rail profiles before and after straightening. Fig. 1a presents a guide rail joint in which the guide rails 11 are so deflected that the installed guide rail line shows a bulge towards the guide plate 31 of the guide rail. In the guide rail joint illustrated in Fig. 1b, the ends of the guide rails 11 are bent towards the back 32 of the guide rails 11. In the guide rail joint in Fig. 1c, the rails are deflected in the direction of the plane of the back 32 of the guide rails 11. The common types of deflection illustrated in Fig. 1a, 1b and 1c are projections of real types of deflection, and real deflections are usually combinations of the types in Fig. 1c and either Fig. 1a or Fig. 1b. These common types of deflection shown in Fig. 1a, 1b and 1c are not the only types possible, but the deflection may be of some other shape, e.g. an S-curvature. The guide rail joints presented in Fig. 1a, 1b and 1c show an exaggerated gap between the backing plate 20 which also serves as a connecting plate, and the guide rails 11, although in a real joint there is no such gap but the plate 20 and the guide rails 11 are tightly pressed together by means of fixing devices 33. Fig. 1d presents the cross-section of the guide rail. The guide rail consists of a T-shaped rail in which the top of the "T" constitutes the back 32 of the guide rail 11 and the leg of the "T" forms the guide plate 31 and guide surfaces. According to the invention, the operations for the checking and correction of the guide rail lines are carried out roughly in the following sequence: The guide rail line, partly or completely installed in an elevator shaft, is checked by means of the measuring device, whereupon the necessary corrections of deflections are carried out. Finally, the correction results can be checked. Fig. 2 presents a measuring device 1 composed of the following parts: supporter 2 for suspending the measuring device so that it will follow the guide rail line, and recorder unit 3. The measuring device 1, which comprises a frame 4, guides 5 and 6, and a distance detector 7, is suspended with a piece of steel wire 8 on the supporter 2, which is fixed to the elevator car unit 35, more particularly to the overhead beam of the car frame, by means of a C-clamp (not shown). Connected to the supporter is a guide element 9 which follows the rail line. The guide element 9 consists of a wheel turning on a bearing, but a sliding element or equivalent would do as well. The guides 5 and 6 of the measuring device 1 are provided with wheels 10 and magnets whose attraction holds the wheels 10 of the guides of the measuring device 1 in contact with the guide rail 11. The distance detector 7 is provided with a wheel 12 which follows the guide rail and whose distance from the frame 4 depends on the mutual positions of wheel 12 and the points of contact of the wheels 10 of the guides 5,6 with the guide rail, and vice versa. The momentary distance data or corresponding signal provided by the distance detector is passed via cable 13 to the recorder unit 3. The recorder unit 3 comprises a signal processing unit 14 and a recorder 15. In the processing unit 14, the signal obtained from the detector is amplified and it can also be filtered or processed in other ways to produce a more usable signal. The detector is preferably so calibrated that the detector reading equals the deviation of the measuring point from the straight line between the points of contact of the wheels 10 with the guide rail. For each guide rail line, both the surface in the direction of the guide plate and the surface in the direction of the back plate of the rail must be checked. Thus, the checking of one guide rail line using the device described above is performed as follows: As explained above, the measuring equipment is mounted on the elevator car so that the measuring device 1 follows one of the guide surfaces of the guide rail line. The elevator is now driven at a low speed from the bottom of the shaft to the top while the recorder is recording the distance signal supplied by the detector. At the top of the shaft, the measuring device 1 is so remounted that it will follow the guide surface perpendicular to the one just checked, whereupon the elevator is driven down while the distance signal is recorded as before. In this way, by driving the elevator once from end to end of the shaft and back, the lateral deflections of one guide rail line can be charted. On the basis of this charting, corrections are carried out where the deflections exceed the allowed limit. Deflections are frequently observed around rail joints. This is due to the fact that the ends of the several-meter-long guide rails 11 are most likely to be exposed to bending forces during manufacture and subsequent operations such as cutting into pieces of a given length, transportation etc. Fig. 3a illustrates the manner in which a deflection like that shown in Fig. 1a is straightened by using shims 34. Shims are placed between the ends of the connecting plate 20 and the back 32 of the guide rail 11. By means of fixing devices 33, the guide rail is tightened against the connecting plate, causing the rail joint to be straightened. Fig. 3b shows how a deflection like that in Fig. 1b is straightened by means of shims 34. A shim or shims are placed between the connecting plate 20 and the back 32 of the guide rail 11 so that the fixing devices 33 are divided into two groups, one of which is above the shims 34 and the other below it along the guide rail. By means of fixing devices 33, the guide rail is tightened against the ends of the connecting plate, resulting in the straightening of the rail joint. There are shims of different thicknesses, so that by choosing from them or using a pack of several shims the required thickness range can be covered in sufficiently small steps, e.g. 0.1 mm. Fig. 4 presents a straightening device 16 consisting of a rigid frame 17, gripping hooks 18 and a screw 19 which turns in a threaded hole (not shown) in the frame. The screw has a sharp tip 30. The screw can also be provided with a separate end piece (not shown) rotatably mounted on it. The rigidity of the straightening device 16 can also be increased e.g. by connecting the hooks with a beam or by replacing the hooks with a U-shaped or J-shaped beam. In this case, however, care must be taken not to allow the structure to hinder the mounting and handling of the connecting plate 20 or its fixing bolts and nuts or the shims 34. Fig. 5 illustrates how the straightening device is used together with the measuring device to straighten a guide rail joint. The screws/nuts holding the connecting plate 20 have been loosened to reduce the friction. The straightening device 16 has been placed across the guide rail joint. The hooks 18 of the straightening device grip the guide rail back plate by one side while the tip 30 of the screw is placed at or beside the seam between the rails 11 on the opposite side of the guide rail back. The measuring device 1, which is similarly placed across the guide rail joint, is used to monitor the progress of the straightening operation. When the result obtained from the measuring device 1 indicates that the guide rail line is no longer noticeably curved around this joint, the loosened fixing devices are tightened again and the straightening device 16 is released. Fig. 6a represents the profile of a guide rail as measured by means of the measuring device of the invention. The diagram clearly shows the bends at the guide rail joints (joint 1, joint 2, etc.). At worst, the deflections measure over one millimetre from the line of the guide rail line, e.g. at the joint indicated with an arrow. Fig. 6b shows the profile of the same guide rail after corrections. The corrected deflections are only a fraction of the those measured before the correction. The profiles in Fig. 6a and 6b were obtained by measuring the surface lying in the direction of the nose of the rail. It is obvious to a person skilled in the art that the invention is not restricted to the examples described above but may instead be varied within the scope of the claims. For example, the following variations or their combinations are covered by the idea of the invention as defined in the claims: The wheels following the rails can be replaced e.g. with sliding elements. The detector measuring the distance of the measuring device 1 from the guide rail surface may also be e.g. an ultrasonic detector or some other type of contactless detector instead of one with a mechanical follower. Instead of a recorder/amplifier combination, the measurement data obtained from the detector may be stored after suitable processing in the memory of a portable computer or storage unit and printed from the memory to a display screen or on paper. In the foregoing, a single-channel type of checking equipment was described, but it would be easy to construct an apparatus with several channels to allow simultaneous inspection of two guide surfaces of the same rail or even two rails. In the straightening device, the screw could be replaced by some other type of device (e.g. hydraulic cylinder) to apply a thrust to the guide rail. The examples concentrate on the straightening of guide rail joints. However, if the straightening equipment is made to larger dimensions, it can be used for the straightening of other parts of the guide rail line as well.

Claims: Procedure for checking the straightness of elevator guide rails and straightening the rails, by successively measuring the distance of the guide rail (11) from a distance detector (7) provided on a measuring device (1) movable along the rail (11), said device comprising two guides (5,6) placed successively along the guide rail and being held in contact with the rail, straightening the guide rail (11) by applying a gripping element (18) to the guide rail above and below the area to be straightened as seen in the longitudinal direction of the rail and applying to the rail (11) a force essentially opposite to the direction of the deflection, thereby monitoring the progress of the straightening operation and fixing the area to be straightened to a rigid backing plate (20). Procedure according to claim 1, for straightening guide rail joints tightened against a backing plate, further comprising the steps of : loosening the fixing devices (33) holding the backing plate (20) before the straightening operation, tightening the loosened fixing devices after the straightness of the guide rail has been monitored, and releasing the straightening device (16). Procedure according to claim 2, further comprising the step of placing at least one shim (34) between the backing plate (20) and the guide rail (11). Apparatus set for performing the procedure according to claim 1, said set comprising a measuring device (1) for movement along the rail, said device comprising two guides (5,6) to be placed successively along the guide rail and to be held into contact with the rail, said measuring device (1) further comprising a distance detector (7) placed between said guides (5,6) for measuring and monitoring the distance of the guide rail (11) from the distance detector (7), a straightening device (16) provided with at least one gripping element allowing the straightening device (16) to be secured against the guide rail by gripping it from one side at points above and below the area to be straightened and with a thrust element (19,30) by means of which a force can be applied to the guide rail (11) from the opposite side of the rail, and at least one backing plate (20) and fixing means (33) for fixing the backing plate (20) to the straightened guide rail. Apparatus set according to claim 4, comprising an assortment of shims (34) to be fitted between a backing plate (20) and a guide rail (11) at a guide rail joint. Apparatus set according to claim 4 or 5, wherein the measuring device (1) is to be mounted on the elevator cabin frame in a manner enabling it to follow the vertical motion of the cabin. Apparatus set according to claim 6, wherein the measuring device (1) is suspended with steel wire (8) or equivalent so as to allow it to follow the vertical motion of the elevator cabin, the steel wire (8) or equivalent being attached to a supporting bar (2) whose one end is supported by and attached to the cabin frame while the other end, to which a wheel turning on a bearing, a sliding element or equivalent is attached, leans against the guide rail so as to follow it. Apparatus set according to any of claims 5 to 7, wherein the measuring device (1) is provided with at least one magnet arranged in such a manner that the magnet attraction holds the guides (5,6) of the measuring device in contact with a guide rail (11).

Inventors: EVANS PETER, SISSALA MIKKO, EVANS, PETER, SISSALA, MIKKO
Applicants: KONE ELEVATOR GMBH
Application year: 1991
Main classification: G01B5
IPC codes: G01B5, B66B19