A hoisting rope for an elevator includes a plurality of longitudinally spaced, discrete targets retained within the rope. The targets have a characteristic that may be monitored by a device that is responsive to that characteristic. In a particular embodiment, the targets are formed from a magnetically permeable material and the monitoring device responds to changes in the magnetic field as the target passes the monitoring device. In another embodiment, the targets are formed from material that reflects electromagnetic energy. In this embodiment, the monitoring device emits electromagnetic energy and is sensitive to the energy that is reflected back from the target. A method to inspect the hoisting ropes includes the steps of positioning the monitoring device proximate to the hoisting rope, moving the hoisting rope relative to the device, and monitoring the targets to determine the spacing between targets. Changes in spacing are indicative of stretching of the rope, and thereby degradation of the rope.
An elevator rope tension monitoring assembly is disclosed. The rope tension monitoring system includes a plurality of sensors that produce an output corresponding to the level of tension in each of the ropes. A controller compares the relative levels of sensed tension and generates a warning signal if a sufficient deviation in the relative level of tension in the ropes is observed.
A load bearing member, such as a polymer cord reinforced belt, includes at least one element of a different material having a characteristic that distinguishes it from the polymer fibers that make up the strands of the cord. The element of second material has a configuration that is repeated along the length of the load bearing member. The configuration of the second material element provides a readily detectible indication of localized strain on the load bearing member. As the load bearing member is strained over time, the configuration of the second material element is also altered. Analyzing the configuration of the second material element along the length of the load bearing member provides information regarding the condition of the belt.
An elevator load bearing assembly, such as a polymer cord, reinforced belt, includes at least one element of a ferromagnetic material associated with each cord that comprises one or more non-ferromagnetic materials. The ferromagnetic element is associated with the cord such that a physical characteristic of the ferromagnetic element changes responsive to strain on the non-ferromagnetic fibers. In one example, the ferromagnetic element is a steel wire that breaks in areas that are strained, caused by bending fatigue, for example. Detecting a number of changes (i.e., breaks) in the ferromagnetic element along the length of the load bearing assembly provides an indication of the belt condition.
A detection method for measuring lift guide rail perpendicularity and an apparatus for practicing the method. The detection method includes the following steps: selecting several monitoring points on a working surface of the lift under testing, measuring seriatim the position coordinates of each monitoring point in the longitudinal direction of the guide rail and the distance between two adjacent monitoring points, measuring seriatim the included angle between the line connecting the two adjacent monitoring points and the plumb line (or the horizontal line), plotting a graphic chart of the perpendicularity error data to obtain the perpendicularity curve for the lift guide rail. The apparatus includes an instrument frame, several detector heads, a displacement sensor, an inclination sensor, a microprocessor and a power supply unit installed on the instrument frame. The advantages of the present invention are: the detected data are picked up directly by the sensors and inputted into the microprocessor, and analyzed and outputted by the microprocessor, so that automation and intellectualization of lift guide rail perpendicularity detection are achieved.
A load bearing assembly in an elevator system includes a plurality of discernable markings on an external surface of the assembly. A monitoring device includes at least one detector that detects locations of the markings along the length of the assembly. Changes in spacing between markings provides an indication of belt loading conditions and provides an ability to determine a condition of the belt relative to whether a replacement of the belt may be necessary. A variety of markings and a variety of detecting arrangements are disclosed.
