WO2010019145A1

WO2010019145A1 - Inspection device and method for deformable elevator buffers

Info

Publication number: WO2010019145A1
Application number: PCT/US2008/073112
Authority: WO
Inventors: Brad Guilani; Peter Viner
Original assignee: Otis Elevator Company
Priority date: 2008-08-14
Filing date: 2008-08-14
Publication date: 2010-02-18

Abstract

An inspection device includes a housing having an internal cavity and an elevator buffer probe disposed partially within the internal cavity and extending from the housing. A spring within the internal cavity provides a bias force extending the elevator buffer probe from the housing toward an initial probe position. An indication is coupled with the elevator probe for indicating an amount of movement of the elevator buffer probe from the initial probe position against the bias force of the spring. A determination as to whether the elevator buffer meets a predetermined performance criterion can be made based on the indication.

Description

INSPECTION DEVICE AND METHOD FOR DEFORMABLE ELEVATOR BUFFERS

BACKGROUND OF THE INVENTION

[0001] This disclosure relates to elevator systems and, more particularly, to a device and method for inspecting deformable elevator buffers and determining whether the buffers meet a performance standard.

[0002] Deformable elevator buffers are commonly used at a bottom of an elevator hoistway to decelerate and stop a mass, such as an elevator car or a counterweight. For instance, one or more buffers may decelerate/stop the elevator car or the counterweight if an overrun condition past an expected stop point occurs.

[0003] Deformable elevator buffers may be formed from an energy absorbing material, such as foam. However, one drawback of using foam is that the foam may change over a period of time. For instance, heat and moisture may chemically degrade the foam and thereby lower the mechanical stiffness of the foam. Therefore, the buffers must be periodically inspected to gauge whether the mechanical stiffness has changed.

[0004] Several different types of devices and methods have been used for inspecting deformable elevator buffers. One somewhat subjective method includes puncturing the buffer with a sharp device, and manually judging whether the mechanical stiffness has changed based on the resistance to puncturing. In addition to this method being subjective, the puncturing irreversibly damages the buffer and may diminish its performance or preclude its further use. Alternatively, the buffer may include a dedicated inspection device, which may be integrated into the foam. The inspection device continually monitors the mechanical stiffness of the buffer. Although effective, the device is invasive and may therefore require complicated manufacturing steps and add expense to the buffer. Moreover, the device is only capable of monitoring a single buffer and does not provide an indication until the mechanical stiffness of the buffer has degraded beyond an acceptable level.

SUMMARY OF THE INVENTION

[0005] An example inspection device includes a housing having an internal cavity and an elevator buffer probe partially within the internal cavity and extending from the housing. A spring within the internal cavity provides a bias force urging the elevator buffer probe from the housing toward an initial probe position. An indicator is coupled with the elevator probe for indicating an amount of movement of the elevator buffer probe from the initial probe position against the bias force of the spring.

[0006] An example method for use with the inspection device includes the steps of manually moving the elevator buffer probe into contact with a deformable elevator buffer, where the contact causes the elevator buffer probe to move against the bias force of the spring; determining an amount of movement of the elevator buffer probe from the indicator; and determining whether the deformable elevator buffer meets a predetermined performance criterion in response to the amount of movement.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

[0008] Figure 1 illustrates an example elevator system.

[0009] Figure 2 illustrates a cross-sectional view of an inspection device.

[0010] Figure 3 illustrates an exploded view of the inspection device of Figure 2.

[0011] Figure 4 illustrates an example operation of an inspection device.

[0012] Figure 5 illustrates another example operation of an inspection device.

[0013] Figure 6 illustrates an example spring for use in an inspection device.

[0014] Figure 7 illustrates a top view of an inspection device.

[0015] Figure 8 illustrates another example inspection device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] Figure 1 illustrates selected portions of an example elevator system 10 that includes a hoistway 12, an elevator car 14, drive members 16, deformable elevator buffers 18, a hoist machine 20, and a counterweight 22 that operate in a known manner to move the elevator car 14 up and down the elevator hoistway 12. The deformable elevator buffers 18 are located toward the bottom of the hoistway 12, for example, in the pit of the hoistway 12. [0017] As shown, each of the deformable elevator buffers 18 may be generally tubular or cylindrical in shape. However, it is to be understood that the deformable elevator buffers 18 may alternatively have other shapes, such as a rectangular shape.

[0018] The deformable elevator buffers 18 serve to buffer the elevator car 14 and the counterweight 22 in the hoistway 12. For example, the elevator car 14 or the counterweight 22 may overrun an expected stop position in the elevator hoistway 12 and move downwards toward the deformable elevator buffers 18. In this regard, the deformable elevator buffers 18 decelerate and stop the elevator car 14 and/or the counterweight 22. In some examples, the deformable elevator buffers 18 may be used in relatively low duty speed systems.

[0019] The deformable elevator buffers 18 may be formed of any suitable type of material for buffering the elevator car 14 and/or the counterweight 22. For example, the deformable elevator buffers 18 are formed of a polymer material. The polymer material may be a foam material, such as polyurethane foam, but other types of polymer material may also be used.

[0020] Over time, the material used to form the deformable elevator buffers 18 may degrade from exposure to heat, moisture, or the like. For example, the material may chemically degrade and cause a change in properties of the deformable elevator buffers 18 that may influence buffering capacity. In this regard, an inspection device 30 as shown in Figure 2 may be used to inspect the deformable elevator buffers 18 and facilitate determining whether the deformable elevator buffers 18 meet a predetermined performance standard. Moreover, the inspection device 30 is portable, reusable, handheld, relatively compact, and may be carried from site to site to inspect deformable elevator buffers 18 at different locations.

[0021] Referring to the cross-sectional view of the inspection device 30 in Figure 2 and an exploded view of the inspection device 30 shown in Figure 3, the inspection device 30 includes a housing 32 having an internal cavity 34 that extends between a first end 38a and a second end 38b of the housing 32. For example, the internal cavity may be a cylindrical bore, but is not limited to any particular shape. The housing 32 is generally cylindrical, but may alternatively have another shape that is also suitable for manual gripping. [0022] An elevator buffer probe 36 is located at least partially within the internal cavity 34 and extends through an opening 37 in the first end 38a. A spring 40 is also located within the internal cavity 34 and provides a bias force that extends the elevator buffer probe 36 from the housing 32 toward an initial probe position, as shown in Figure 2. An indicator 42 is coupled with the elevator buffer probe 36 to indicate an amount of movement of the elevator buffer probe 36 from the initial probe position against the bias force of the spring 40.

[0023] In this example, the housing 32 includes a cap 44 for containing the spring 40 within the internal cavity 34. The cap 44 is circular and fits within the second end 38b of the housing 32. For example, the cap may be thread-fit or snap-fit into the second end 38b. The cap 44 includes an opening 46 through which the indicator 42 extends when the elevator buffer probe 36 moves from the initial probe position.

[0024] The elevator buffer probe 36 includes a shaft portion 48 that extends between a first end 50 and a second end 52. The first end 50 includes a stop 54 that has a larger diameter than the shaft portion 48. The spring 40 fits over the shaft portion 48 and abuts the stop 54. The spring 40 is at least partially compressed in the internal cavity 34 such that the spring 40 provides a bias force that urges the stop 54 into contact with the first end 38a. Thus, the stop 54 establishes the initial position of the elevator buffer probe 36.

[0025] The second end 52 of the shaft portion 48 is extendable from the housing 32 through the opening 46 of the cap 44. In the illustrated example, the second end 52 includes the indicator 42. The indicator 42 therefore extends through the opening 46 and is visible when the elevator buffer probe 36 moves from the initial position.

[0026] In the illustrative embodiment, the second end 52 is generally circular in cross-section and includes a generally planar surface 64 serving as the indicator 42. For example, a lower section 66 of the planar surface 64 serves as a first indicating portion, such as a pass condition. An upper section 68 of the planar surface 64 serves as a second indicating portion, such as a fail condition. The lower section 66 and the upper section 68 may include a color indication (e.g., green and red), a graduated scale, or other pass/fail indication. Alternatively, the indicator 42 may be any type of indicator for providing a pass/fail indication, including visual indicators such as a light indicator that illuminates when the elevator buffer probe 36 moves a predetermined amount from the initial probe position or audible or other easily perceivable indicators. Given this description, one of ordinary skill in the art will recognize other types of indicators to meet their particular needs.

[0027] The elevator buffer probe 36 also includes an indenter shaft 70 that extends between a tip 72 and the stop 54. The diameter of the shaft 70 is smaller than the diameter of the shaft portion 48. In this example, the tip 72 is rounded and is relatively blunt to avoid puncturing or damaging the deformable elevator buffers 18. As may be appreciated, the tip 72 may be formed in other blunt shapes, such as a squared-off shape. Likewise, the cross- sectional diameter of the indenter shaft 70 is relatively large to avoid puncturing or damaging the deformable elevator buffers 18. For example, the cross-sectional diameter of the indenter shaft 70 may be about 4 - 8 millimeters (about 0.16 - 0.31 inches). In a further example, the indenter shaft 70 is about 5 millimeters (about 0.2 inches) in diameter. If the diameter is too small, the indenter shaft 70 may puncture the deformable elevator buffer 18, and if the diameter is too large, a large spring 40 may be required. The term "about" as used in this description relative to distances or other values refers to possible variation in the given value, such as normally accepted variations or tolerances in the art.

[0028] The spring 40 may be a coil spring having a known spring constant. In this example, the coils of the spring 40 are of uniform diameter from end to end of the spring 40. The spring constant of the spring 40 may be selected to correspond to a deformability of the deformable elevator buffers 18, as will be discussed in more detail below.

[0029] The inspection device 30 may be used to inspect the deformable elevator buffers 18 and facilitate determining whether the deformable elevator buffers 18 meet predetermined performance criterion. For instance, the predetermined performance criterion may correspond to a desired level of performance of the deformable elevator buffers 18.

[0030] A user may move the tip 72 of the elevator buffer probe 36 into contact with one of the deformable elevator buffers 18 by pressing the indenter shaft into the deformable elevator buffer 18. Upon contact, the deformable elevator buffer 18 causes the elevator buffer probe 36 to move against the bias force of the spring 40. That is, the indenter shaft 70 retracts into the internal cavity 34 of the housing 32 and causes the indicator 42 to extend from the housing 32 through the opening 46. The amount of movement of the elevator buffer probe 36 relative to the housing 32 corresponds to the amount of deflection of the deformable elevator buffer 18 and determines how much of the indicator 42 becomes visible. Thus, for a relatively small amount of probe movement (i.e., large buffer deformation), only the upper section 68 of the indicator 42 may become visible. For a relatively large amount of probe movement (i.e., small buffer deformation) the upper section 68 and the lower section 66 of the indicator 42 may become visible.

[0031] Figure 4 illustrates operation of the inspection device 30 relative to a degraded deformable elevator buffer 18'. In this example, the deformable elevator buffer 18' deforms a relatively large amount in response to contact with the elevator buffer probe 36. For instance, pressing the indenter shaft 70 into the deformable elevator buffer 18' compresses the spring 40. In this case, since the deformable elevator buffer 18' is not very stiff, the deformable elevator buffer 18' only moves the elevator buffer probe 36 a small amount against the bias force of the spring 40 such that only the upper section 68 of the indicator 42 becomes visible. Thus, the indicator 42 indicates a fail condition to a user.

[0032] Figure 5 illustrates operation of the inspection device 30 relative to a non- degraded deformable elevator buffer 18". In this example, the deformable elevator buffer 18" deforms a relatively small amount in response to contact with the elevator buffer probe 36. In this case, since the deformable elevator buffer 18" is not degraded and is relatively stiff (compared to the deformable elevator buffer 18'), the deformable elevator buffer 18" moves the elevator buffer probe 36 a large amount against the bias force of the spring 40 such that both the upper section 68 and the lower section 66 of the indicator 42 are visible. Thus, the indicator 42 indicates a pass condition to a user.

[0033] The spring 40 and spring constant of the spring 40 may be preselected based upon a given deformable elevator buffer 18. For instance, the spring constant may correspond to known amounts of deflection of polyurethane foam such that the amount of movement of the elevator buffer probe 36 against the bias force of the spring 40 corresponds to a desired predetermined performance criterion of the deformable elevator buffer 18. In one example, a suitable spring constant may be determined empirically by heat aging a given elevator buffer or comparable sample and utilizing numerous test springs having different spring constants to determine a spring constant that is suitable. Thus, the spring constant of the spring 40 is not limited to any particular spring constant, as long as the spring 40 is not too soft or too hard to register a fail condition of a degraded elevator buffer. In one example, the spring constant of the spring 40 may be about 15 lbs/in (268 kg/m) and is suitable for inspecting deformable elevator buffers 18 made of polyurethane foam. In a further example, the spring constant may be about 26 lbs/in (464 kg/m).

[0034] Optionally, as shown in Figure 5, the housing 32 may include a tactile layer 80 around the outside of the housing 32. For instance, the tactile layer 80 may be a polymer, such as an elastomer, that facilitates gripping the inspection device 30. For instance, the tactile layer 80 may be manually fit over the housing 32, or overmolded onto the housing 32 in using a suitable molding process.

[0035] Figures 6 illustrates another example spring 140 that may be used in the inspection device 30 instead of the spring 40 shown in previous examples. In this disclosure, like reference numerals designate like elements where appropriate, and reference numerals with the addition of one hundred or multiples thereof designate modified elements. It is to be understood that the modified elements incorporate the same features and benefits of the corresponding original elements, except where stated otherwise. In this example, the spring 140 includes a first coil section 141a and a second coil section 141b. The first coil section 141a includes a diameter d_\, and the second coil section 141b includes a second diameter d₂ that is smaller than the first diameter d_\. Thus, the first coil section 141a may have a different spring constant than the second coil section 141b and thereby provide a varying amount of force necessary to move the elevator buffer probe 36. For instance, a relatively low amount of force may initially be necessary to move the elevator buffer probe 36 against a bias force of the second coil section 141b, and a relatively larger amount of force may be necessary to move the elevator buffer probe 36 further against a larger bias force provided by the first coil section 141a.

[0036] Figure 7 illustrates a top view of another example indicator 142 that may be used instead of the indicator 42 of the previous examples. In this example, the indicator 142 has a non-circular cross-section (e.g., a square) that is extendable through the opening 46 of the cap 44, similar to as described above for the indicator 42. The opening 46 and the cross-section of the indicator 142 are differently shaped such that only the corners of the indicator 142 may contact the sides of the opening 46, but any such contact is minimal so as not to interfere with the spring. Thus, the flat sides of the indicator 142 are spaced from the sides of the opening 46. For example, if the sides of the indicator 142 include symbols, markings, paint, or other type of indication, the indication will not rub against the sides of the opening 46 and wear off with use of the inspection device 30.

[0037] In another embodiment of the inspection device 230 shown in Figure 8, the inspection device 230 includes a handle portion 286. In the illustrated embodiment, the handle portion 286 is T-shaped; however, the handle portion 286 may alternatively be any shape suitable for holding the inspection device 230. In this case, the T-shaped handle portion 286 has a larger width than the lower portion of the housing 232, such that the inspection device 230 is adapted for the user to hold the handle portion 286 so that the tip 72 of the indenter shaft 70 indents into the buffer.

[0038] The handle portion 286 also includes a shaft portion 288 coupled to the cap 44. For example, the handle portion 286 may be integrally formed with the cap using molding, casting, or the like. Alternatively, the handle portion 286 may be welded to the cap 44, or coupled using fasteners or adhesive. The shaft portion 288 includes an internal cavity 290 that aligns with the internal cavity 34 of the housing 232. Similar to the example of Figure 2, the inspection device 230 includes an elevator buffer probe 236 having a shaft portion 248 that extends between a first end 250 and a second end 252. In this example, the first end 252 may extend into the internal cavity 290 of the handle portion 286 when the elevator buffer probe 236 is moved from an initial position.

[0039] In this embodiment, the housing 232 also includes a window 292 that is at least partially aligned with a generally planar surface 264 of probe 236 serving as an indicator 242. For example, a lower section 266 of the planar surface 264 serves as a first indicating portion, such as a pass condition. An upper section 268 of the planar surface 264 serves as a second indicating portion, such as a fail condition. The lower section 266 and the upper section 268 may include a color indication (e.g., green and red), a graduated scale, or other pass/fail indication. Alternatively, the indicator 242 may be any type of indicator for providing a pass/fail indication, including visual indicators such as a light indicator that illuminates when the elevator buffer probe 236 moves a predetermined amount from the initial probe position or audible or other easily perceivable indicators. Given this description, one of ordinary skill in the art will recognize other types of indicators to meet their particular needs. [0040] The disclosed inspection devices 30 and 230 may be used to inspect the deformable elevator buffers 18 and facilitate determining whether the deformable elevator buffers 18 meet a predetermined performance criterion. The inspection devices 30 and 230 therefore provide the benefits of being relatively compact and portable such that a user can carry the inspection device 30 or 230 between different locations. Moreover, the inspection devices 30 and 230 have a relatively simple design and do not damage or puncture the deformable elevator buffers 18.

[0041] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.

[0042] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

CLAIMSWhat is claimed is:

1. An inspection device comprising: a housing having an internal cavity; an elevator buffer probe disposed partially within the internal cavity and extending from the housing; a spring within the internal cavity, the spring providing a bias force urging the elevator buffer probe from the housing toward an initial probe position; and an indicator coupled with the elevator buffer probe, the indicator indicating an amount of movement of the elevator buffer probe from the initial probe position against the bias force of the spring.

2. The inspection device as recited in claim 1, wherein the indicator comprises a pass/fail indication.

3. The inspection device as recited in claim 1, wherein the elevator buffer probe includes a shaft portion having a first end and a second end, the first end including a stop establishing the initial probe position.

4. The inspection device as recited in claim 3, wherein the elevator buffer probe includes an indenter shaft extending between an indenter tip and the stop, the indenter shaft extending from the housing when the elevator buffer probe is in the initial probe position.

5. The inspection device as recited in claim 3, wherein the second end includes the indicator and is extendable through an opening of the housing when the elevator buffer probe moves from the initial probe position.

6. The inspection device as recited in claim 5, wherein the opening is circular and the second end includes a non-circular cross-section.

7. The inspection device as recited in claim 5, wherein the diameter of the second end is larger than the diameter of the first end of the shaft.

8. The inspection device as recited in claim 1, further comprising a handle portion on an end of the housing opposite from another end from which the probe extends from the housing.

9. The inspection device as recited in claim 1, wherein the housing includes a first end and a second end, and the elevator buffer probe extends from the first end when the elevator buffer probe is in the initial probe position and extends from the second end when the elevator buffer probe moves from the initial probe position.

10. The inspection device as recited in claim 1, wherein the elevator buffer probe includes an indenter shaft extending from the housing when the elevator buffer probe is in the initial probe position, and the indenter shaft includes a rounded tip.

11. The inspection device as recited in claim 10, wherein the indenter shaft includes a circular cross-section having a diameter of about 4-8 millimeters.

12. The inspection device as recited in claim 10, wherein the indenter shaft includes a circular cross-section having a diameter of about 5 millimeters.

13. The inspection device as recited in claim 1, further comprising a tactile layer disposed on an outside portion of the housing.

14. The inspection device as recited in claim 1, wherein the spring is a coil having a first section with a first coil diameter and a second section with a second, different coil diameter.

15. The inspection device as recited in claim 1, wherein the internal cavity is a cylindrical bore.

16. The inspection device as recited in claim 1, wherein the spring includes a spring constant of 15 lbs/in (268 kg/m).

17. The inspection device as recited in claim 1, wherein the spring includes a spring constant of 26 lbs/in (464 kg/m).

18. A method for use with an inspection device including a housing having an internal cavity, an elevator buffer probe disposed partially within the internal cavity and extending from the housing, a spring within the internal cavity that provides a bias force extending the elevator buffer probe from the housing toward an initial probe position, and an indicator coupled with the elevator buffer probe, the method comprising: placing the elevator buffer probe into contact with a deformable elevator buffer, such that the elevator buffer probe is caused to move against the bias force of the spring; pressing the elevator buffer probe against the deformable elevator buffer such that the elevator buffer probe moves further against the bias force of the spring, causing said indicator to become perceivable; and determining whether the deformable elevator buffer meets a predetermined performance criterion based on the indication of said indicator.

19. The method as recited in claim 18, wherein the indicator further comprises a pass/fail indication and the step of determining whether the deformable elevator buffer meets a predetermined performance criterion is based on the pass/fail indication.

20. The method as recited in claim 18, further comprising determining that the deformable elevator buffer does not meet the predetermined performance criterion if the indicator indicates a fail condition, and determining that the deformable elevator buffer meets the predetermined performance criterion if the indicator indicates a pass condition.