Sealing strip wear monitoring system and assembly thereof

Abstract

A seal strip and wear monitoring system includes: a seal strip having an upper surface; and a wear monitoring system. The wear monitoring system includes: a sensing portion including a plurality of electrical traces, each of the electrical traces including an uppermost portion substantially parallel to and positioned at a depth from an upper surface of the seal strip, where the uppermost portion of each trace has a depth different from the depth of the other electrical traces; and a signal processing portion electrically connected with the electrical trace, the signal processing portion including circuitry configured to detect an electrical signal from the trace and determine when an uppermost portion of the trace is damaged.

Description

[0001] Related Applications

[0002] This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 481,835, filed on January 27, 2023, the disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present invention generally relates to papermaking, and more particularly to suction rolls and equipment within a paper machine. Background Art

[0004] Paper manufacturing inherently requires water removal at many stages of the production process. Generally, pulp (a slurry composed of water, wood, and other fibers) rides on top of a felt (in the form of a wide band), which serves as a carrier for the wet slurry before actual paper formation. The felt is used to carry the slurry in the wet section of the paper machine until enough water has been removed from the slurry to allow the paper to be processed without additional support added by the felt.

[0005] Quite commonly at the wet end of a paper machine, an initial water removal is accomplished using a suction roll (which can be a couch roll, a pick-up roll, or a press suction roll) in a press section, which is used in combination with a solid standard press roll (or against a Yankee dryer in a tissue paper machine), and the press roll is aligned and mated with the suction roll. The felt slurry carrier is pressed between these two rolls.

[0006] The main components of the suction roll 10 include a hollow housing 12 ( Figure 1 ), the hollow housing 12 is made of stainless steel, bronze, or other metal, and has tens of thousands of holes drilled radially around the circumference of the roll in a specified pattern. The size of these holes is calibrated (in the range of less than 1 / 8 inch to nearly 1 / 4 inch) and engineered according to the specific paper material to be processed. It is these holes that form the "ventilation openings" for water removal. This ventilation opening can generally be in the range of about 20% to 45% of the effective roll surface area. The suction roll housing is driven by a drive system that rotates the housing around a fixed core called a suction box.

[0007] The suction box 20 ( Figure 2) can be considered a conventional long rectangular box with a lid on top and ports on the ends, bottom, or sides. The ends of the box (specifically, the drive end) typically have guide bearings, the inner race of which is a guide bushing or bearing that is slidably mated to a journal on the suction box, and the outer race is pressed onto the rotating housing. The suction box 20 is connected to a suction source (e.g., a vacuum pump). An exemplary suction box and housing are shown in U.S. Patent No. 6,358,370 to Huttunen, the disclosure of which is hereby incorporated herein by reference in its entirety.

[0008] To utilize the holes in the housing, these ports must be used to form a vacuum zone 30 in the inner side of the suction roll housing, in the area directly below the pulp being processed. This is accomplished by the suction box 20, using a slotted retainer 32 that holds seals on both sides along the long axis of the suction box. Figure 2 The slotted retainer 32 is shown, and Figure 3 and Figure 4 two seals 34, 34' in the form of strips (hereinafter referred to as "sealing strips") are shown. In addition to these long seals, there are two shorter seals (referred to as end paper frames) at the short ends (referred to as the operating end and the drive end), and the shorter seals allow for some axial adjustment as needed to accommodate various paper widths.

[0009] The sealing strips 34, 34' are typically made of rubberized polymeric graphite and remain in almost constant contact with the inner surface of the housing 12 during operation (see Figure 3 and Figure 4 ). A constant vacuum is drawn between the sealing strips 34, 34'. This allows a vacuum zone 30 to be formed below the paper 40 as the paper 40 passes over the roll 10. The sealing strips 34, 34' are biased upward toward the suction roll housing 12 by a load tube 42, which is a sealed hose that extends the entire length below the sealing strips 34, 34'. The pressure in the load tube 42 causes the load tube 42 to expand (much like the air in a balloon) and lift the sealing strips 34, 34' toward the inner surface of the housing 12. This effect, along with the help of the system vacuum from the suction box 20 and the laminar flow of the previously mentioned lubricating water, forms a seal between the edges of the sealing strip 34 and the inner side of the housing 12.

[0010] In practical applications, in a normally operating suction roll, the sealing strips 34, 34' never directly contact the inner side of the suction roll housing 12. If the sealing strips 34, 34' contact the housing 12, they will wear away and will quickly lose their sealing ability. To eliminate or significantly reduce this wear and provide a seal, water is applied along the length of the sealing strips 34, 34' by means of a lubricating spray formed by water flowing through the spray nozzles 24 (see Figure 2) This spray keeps the sealing strips 34, 34' lubricated by means of the laminar flow of water between the sealing surface and the inner surface of the housing 12.

[0011] The amount of water used for lubrication should be properly adjusted so that an appropriate amount of lubrication is applied to keep the sealing strips 34, 34 lubricated, but not so much as to become a problem for the pulp being processed or to waste water. Additionally, the process water used in a paper mill may contain chemicals and a large number of particles, and during normal operation, the particles may clog the lubrication spray nozzles 24. Since these nozzles 24 are located inside the rotating housing 12, the paper machine operator cannot see these nozzles 24.

[0012] The sealing strips are typically replaced regularly after a certain degree of wear. However, since the paper machine operator or anyone attempting to view the sealing strips cannot see the sealing strips inside the water suction roll, many conditions inside the operating water suction roll, including the degree of wear of the sealing strips, are unknown. Accordingly, a reliable method for detecting the wear of the sealing strips may be desired that informs the paper machine operator that the equipment needs maintenance before a failure occurs. Summary of the Invention

[0013] As a first aspect, embodiments of the present invention relate to a sealing strip and wear monitoring system. The system includes a sealing strip having an upper surface and a wear monitoring system. The wear monitoring system includes: a sensing portion including a plurality of electrical traces, each of the electrical traces including an uppermost portion positioned at a certain depth from the upper surface of the sealing strip, wherein the depth of the uppermost portion of each trace is different from the depth of the uppermost portion of the other electrical traces; and a signal processing portion electrically connected to the electrical traces, the signal processing portion including circuitry configured to detect an electrical signal from the traces and determine when the uppermost portion of the traces is damaged.

[0014] As a second aspect, embodiments of the present invention relate to a sealing strip monitoring system, which includes: a sealing strip having an upper surface; a printed circuit board (PCB) having a first finger and a second finger and a main panel; a wear monitoring system; and a temperature monitoring system at least partially mounted on the PCB. The wear monitoring system includes: a sensing portion including a plurality of electrical traces, each of the electrical traces including an uppermost portion generally parallel to the upper surface of the sealing strip and positioned at a certain depth from the upper surface of the sealing strip, wherein the depth of the uppermost portion of each trace is different from the depth of the uppermost portion of the other electrical traces, and wherein the uppermost portion of the electrical traces is located on the first finger; and a signal processing portion electrically connected to the electrical traces, the signal processing portion including circuitry mounted on the main panel of the PCB and configured to detect an electrical signal from the traces and determine when the uppermost portion of the traces is damaged. Description of the Drawings

[0015] Figure 1 Is a perspective end view of a typical water suction roll of a paper machine.

[0016] Figure 2 Is an enlarged perspective end view of the water suction box area of a typical water suction roll.

[0017] Figure 3 Is an end view of the water suction box area and the sealing strip of a conventional water suction roll.

[0018] Figure 4 Is an end view of the water suction box area and the sealing strip of another conventional water suction roll.

[0019] Figure 5 Is a schematic side view of a sealing strip and a wear monitoring system according to an embodiment of the present invention.

[0020] Figure 6 Is Figure 5 A schematic diagram of the wear monitoring system.

[0021] Figures 7A - 7C Is an illustration Figure 5 Of the sequential perspective view of the structure of the sensing part of the wear monitoring system.

[0022] Figure 8 Is Figure 5 A perspective view of the electronic components of the wear monitoring system.

[0023] Figure 9 Is a schematic diagram of a wear monitoring system according to an alternative embodiment of the present invention.

[0024] Figure 10 Is a schematic diagram of a wear monitoring system according to an alternative embodiment of the present invention.

[0025] Figure 11 Is a plan view of a sealing strip monitoring system according to an embodiment of the present invention.

[0026] Figures 12A - 12D Is an illustration Figure 11 Of the sequential perspective view of the structure of the sealing strip monitoring system.

[0027] Figure 13 Is a schematic diagram of a wear monitoring system according to another embodiment of the present invention. Detailed Description

[0028] The present invention will be described more fully hereinafter, in which embodiments of the present invention are shown. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, like reference numerals always refer to like elements. For clarity, the thickness and dimensions of some components may be exaggerated.

[0029] In addition, for ease of description, spatial relative terms (such as "under", "below", "lower", "above", "upper", etc.) may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "under" or "below" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary term "under" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatial relative descriptors used herein are to be interpreted accordingly.

[0030] Well-known functions or constructions may not be described in detail for the sake of brevity and / or clarity.

[0031] Now referring to the drawings, in Figures 5 - 8 a sealing strip 100 and an accompanying wear monitoring system 120 are shown. Except for the accommodation space for the wear monitoring system 120 described below, the sealing strip 100 largely has a conventional design in the above-described manner: it is elongated and has a generally constant cross-section; it resides within a channel-shaped retainer and is supported by a load tube against its lower surface 105; a load cell biases the sealing strip 100 upward (i.e., toward the housing of the water absorption roller) such that its upper surface 106 faces the housing and contributes to sealing therewith; and it is formed of a polymeric material such as rubber (which may be filled with a filler such as graphite).

[0032] Now referring to Figure 5 , the wear monitoring system 120 is shown as being embedded within the sealing strip 100. The wear monitoring system 120 includes a sensing portion 122, a signal processing portion 124, and a cable 126 that connects the sensing portion 122 to the signal processing portion 124. The sealing strip 100 includes a channel 108 in its lower surface, and the cable 110 between adjacent wear monitoring systems 120 is routed within the channel 108. In addition, a cap 128 surrounds the upper end portion of the sensing portion 122 and is flush with the upper surface 106 of the sealing strip 100.

[0033] Now referring toFigure 6 , the sensing portion 122 generally includes a printed circuit board (PCB) 123 having traces 130 (discussed in more detail below). The signal processing portion 124 generally includes a PCB 125 having processing components (also discussed in more detail below). Additionally, although shown herein as separate PCBs, the sensing portion 122 and the signal processing portion 124 can be formed on the same PCB (e.g., see system 420 shown below in Figures 11 - 12D ).

[0034] Now referring to Figure 6 , a wear monitoring system 120 is schematically shown. The sensing portion 122 shown at the top in Figure 6 includes a plurality of electrical traces 130 on a PCB 123. As can be seen in Figure 6 , the traces 130 are laid on the PCB 123 as a series of generally U-shaped lines, where the upper horizontal "extensions" 132 (the uppermost part of each trace 130) of each trace 130 are spaced apart from adjacent upper extensions 132 by a certain distance such that the upper extensions 132 are spaced apart from each other (in some embodiments, they may be spaced evenly or regularly, in this example, spaced 1 / 32 inch apart, for example), and are each at a different "depth" (i.e., the distance from the upper surface 106 of the sealing strip 100). One vertical extension 134 of each trace 130 is connected (via a cable 126) to a switch 140 on the PCB 125 of the signal processing portion 124, and the other vertical extension 136 of each trace 130 is connected (also via a cable 126) to a corresponding capacitor 142 mounted on the PCB 125. (It should be understood that in some embodiments, the capacitor 142 can be mounted at or near the trace 130 itself).

[0035] Still referring to Figure 6 , the signal processing portion 124 further includes a microcontroller 146, a power supply 148, and a communication driver 150. The switch 140 is directly connected to the microcontroller 146 via parallel charge and discharge resistors 152a, 152b and a sampling buffer 153. The microcontroller 146 is connected to the power supply 148 and the communication driver 150. Both the power supply 148 and the communication driver 150 are connected to a data and power bus 154. Additionally, all the capacitors 142 are connected in parallel and connected to ground.

[0036] The wear monitoring system 120 operates by repeatedly sampling the respective traces 123 and their corresponding capacitors 142. When a direct connection is created between the charge resistor 152a and the capacitor 142, the capacitor 142 begins to charge. This relationship can be understood as

[0037]

[0038] and

[0039] τ = RC

[0040] wherein:

[0041] Vc is the voltage potential across the capacitor with respect to common ground, in volts;

[0042] Vs is the voltage potential of the power supply device with respect to common ground, in volts;

[0043] e is Euler's number, which is an irrational number presented as 2.71828 in the present disclosure;

[0044] t is the total charging time of the capacitor, in seconds, and is typically the time constant multiplied by an integer;

[0045] τ (tau) is the time constant, in seconds;

[0046] R is the resistance of the charging resistor, in ohms; and

[0047] C is the capacitance of the capacitor, in farads.

[0048] For Figure 6 the system illustrated in, in the case where the capacitor 142 is a 10 nF capacitor, the charging resistor 152a is 100 kΩ, and the supply voltage is 5 V, the time constant τ is 1 ms. Based on the knowledge that a capacitor typically reaches its steady-state period (–99% of its maximum charge) after 5τ, it can be calculated that the voltage of the capacitor 142 should be approximately 4.97 V after 5 ms. If the measured voltage across the sampled capacitor 142 is within the threshold of this value (e.g., within 10%), it can be assumed that the connection between the capacitor 142 and the charging resistor 152a is intact.

[0049] It should also be understood that in some embodiments, the discharge rate can be defined by the following equation:

[0050] Vc = Vs * e (-(t / τ)) where each parameter of the equation is as described above.

[0051] As the seal strip 100 is used, it undergoes wear. Once the upper surface 106 of the seal strip 100 wears to the farthest trace 130a (i.e., the trace of its extension 132 closest to the upper surface of the seal strip 100 – see Figure 6)To the extent that the material of the upper sealing strip 100 is worn away, the trace 130a is also worn. The wear of the trace 130a breaks the connection between its corresponding capacitor 142a and the charging resistor 152a. Therefore, when the switch 140 samples the connection to the capacitor 142a, the measured voltage exceeds the acceptable range, indicating that the trace 130a has been damaged and, thus, that the wear on the sealing strip 100 has reached the depth of the trace 130a.

[0052] As the sealing strip 100 continues to wear, the upper surface 106 is worn away until it reaches the extension 132 of the second outermost trace 130b. Continued wear of the trace 130b breaks the connection to its corresponding capacitor 142b, which is detected when the switch 140 attempts to connect to the capacitor 142b. This process can continue until (a) all of the traces 130 are broken or (b) the user chooses to replace the worn sealing strip 100 when a specific wear depth is reached.

[0053] Figures 7A - 7C An exemplary configuration and construction of the sensing portion 122 are illustrated. As Figure 7A shown, the PCB 123 includes traces 130 and contact pads 131 for connecting the traces 130 to the signal processing portion 124 via a cable 126. Figure 7B The application of the cap 128 for isolating and protecting the traces 130 is illustrated. Figure 7C It is shown that any space between the cap 128 and the PCB 123 can be filled with a potting compound 129, and the attachment of the cable 126 to the contact pad 131 is also shown.

[0054] Figure 8 An exemplary configuration of the signal processing portion 124 is illustrated. As Figure 8 shown, the capacitors 142 are mounted on the PCB 125, as is the control circuitry (i.e., the microcontroller 146, the power supply 148, and the communication driver 150). Figure 8 The cable 126 attached to a contact pad (not shown) at one end of the PCB 125 is shown. Additionally, the connector 160 is mounted near either end of the PCB 125 so that the system 120 can be "daisy-chained" along the length of the sealing strip 100 to other systems 120, forming an overall assembly that can provide a full-length wear profile of the sealing strip 100.

[0055] An alternative embodiment of the wear monitoring system is illustrated in Figure 9within and is broadly labeled 220. The wear monitoring system 220 is similar to the wear monitoring system 120 in that it includes a sensing portion 222 mounted on a PCB 223 having a trace 230 and a signal processing portion 224 mounted on a PCB 225, wherein the sensing portion 222 and the signal processing portion 224 are connected by a cable 226. However, the wear monitoring system 220 relies on a plurality of resistors 242 connected to the trace 230 of the sensing portion 222 instead of capacitors. These resistors 242 are connected to ground and are connected in parallel with each other. The detection circuit mounted on the signal processing portion 224 is also slightly different: the switch 240 is directly connected to the microcontroller 246 and is connected to a resistor 252, which in turn has one end connected to a voltage supply 247 and the other end connected to the microcontroller 246 through a sampling buffer 253.

[0056] When the switch 240 connects the resistor 252 to one of the resistors 242, this relationship can be defined as:

[0057]

[0058] where:

[0059] Vout is the output of the voltage divider with respect to common ground, in volts;

[0060] Vs is the voltage potential of the power supply with respect to common ground, in volts;

[0061] Rp is the value of the main resistor, in ohms; and

[0062] Rs is the value of the selected resistor in the resistor bank, in ohms.

[0063] For Figure 9 the system 220 illustrated in, for a supply voltage of 5V, the resistor 242 is 10 kΩ and the resistor 252 is also 10 kΩ, and the output voltage Vout is half of the supply voltage or 2.5V.

[0064] As described above, when the seal strip 200 wears during use, it eventually reaches and damages the extension 232 of the outermost trace 230a. When the switch 240 connects the resistor 242a to the charging resistor 252, the voltage should be approximately 2.5V. If this measurement changes by more than a certain threshold (e.g., 10%), the system 220 recognizes that this measurement indicates that the seal strip 200 has worn to the depth of the extension 232 of the trace 230a.

[0065] The voltage reading can be 0 V (indicating a short circuit) or 5 V (indicating an open circuit). An open circuit indicates that no current is passing through trace 230a, while a short circuit indicates that the electrical trace 230a is in contact with an external component, such as lubricating water. Either event indicates that the sealing strip 200 has worn down to the level of trace 230a.

[0066] Like the wear monitoring system 120, this process is repeated for the other traces 230 until all the traces 130 are disconnected, or the user chooses to replace the worn sealing strip 100 when a specific wear depth is reached.

[0067] Another embodiment of the wear monitoring system is shown in Figure 10 and is broadly labeled 320. In this system, the traces 330 of the sensing portion 322 are generally L-shaped. The traces 330 are connected in parallel via a common trace 331, which is then connected to the signal processing portion 324. Resistors 341 are also located on the common trace 331 between each pair of adjacent traces. Resistors 342 connected to the respective traces 330 are located on the PCB 323 of the sensing portion 322. In this embodiment, the strength of the resistors 342 varies. The resistors 342 are connected in parallel with each other via traces 343, which are connected to trace 331.

[0068] The signal processing portion 324 does not have a switch; instead, the common trace 331 is directly connected to the microcontroller 346 via trace 357. A constant current source 355 is also connected to trace 357.

[0069] System 320 operates relying on Ohm's law (voltage = current * resistance). For resistors 341 connected in series, the resistance is

[0070] Rt = R1 + R2 + R3... + Rn

[0071] where Rt is the total resistance and Rn is the resistance of each resistor. For resistors 342 connected in parallel, the resistance is calculated as

[0072]

[0073] Therefore, since the current is constant, a change in the measured voltage indicates a change in the resistance of the system. This resistance change occurs when the traces 330 are damaged due to wear on the sealing strip 300.

[0074] Using Figure 10 the resistance values shown in, when all the traces 330 are intact, the microcontroller 346 reads a voltage of approximately 10 V. As the sealing strip 300 wears, about a 1 V increase is detected for each trace 330 as it wears away.

[0075] Those skilled in the art will appreciate that while voltage signals and current signals are monitored in the above embodiments, in other embodiments, combined voltage and current signals may be detected and employed.

[0076] Figure 11 Another wear monitoring system is illustrated and is broadly labeled 420. The wear monitoring system 420 is mounted on a single PCB 423 (i.e., both the sensing portion 422 and the signal processing portion 424 are located on the same PCB 423). As such, there are no cables such as cable 126; instead, traces 430 directly connect to components of the signal processing portion 424. The PCB 423 is flexible such that it can be bent so that the fingers 421 on which the sensing portion 422 is mounted can be oriented generally perpendicular to the main portion 427 of the PCB 423. Any of the wear monitoring systems 120, 220, 320 described above can be mounted on the PCB 423.

[0077] In this embodiment, a temperature monitoring system 470 is also mounted on the PCB 423. The temperature monitoring system 470 can take many forms, including the form described in U.S. Provisional Patent Application No. 63 / 375,587, filed on September 14, 2022, the disclosure of which is hereby incorporated herein by reference in its entirety. The sensing portion 472 of the temperature monitoring system 470 is mounted on the finger 471 of the PCB 423, and the signal processing components of the temperature monitoring system 470 are mounted on the main portion 427 of the PCB 423. The wear monitoring system 420 and the temperature monitoring system 470 together form an integral seal monitoring system 480.

[0078] The installation of the seal monitoring system 480 is illustrated in Figures 12A - 12D . Figure 12A The lower surface of the seal 400 is illustrated, in which a channel 408 has been formed and holes 409, 410 have been drilled perpendicular to the channel 408. Figure 12B The system 480 is illustrated installed in the seal 400, where the fingers 421, 471 are inserted into the holes 409, 410 to deploy the sensing portions 422, 472, and the main portion 427 of the PCB 423 is installed in the channel 408 itself. Figure 12C The connection of the cable 490 to the PCB 423 is illustrated to allow the above-described "daisy-chain connection" of the system 480 along the length of the seal 400. Figure 12D The addition of a potting compound 492 (e.g., elastomeric silicone) to fill the channel 408 is illustrated.

[0079] It should also be noted that any seal strip discussed herein can be implemented with different components to perform different functions. For example, the load tube can be replaced with other components (such as springs, elastic pads, etc.) that bias the seal strip towards the water-absorbing roller. The seal strip retainer can be configured differently. Other variations can also be employed.

[0080] Another variation of the wear monitoring system is shown in Figure 13 and is generally labeled 520. The sensing portion 522 includes a plurality of traces 530. The traces 530 differ from those shown in the wear monitoring systems 120, 220, 320, 420 in that: (a) the traces 530 depict an arcuate path at their upper end portions; and (b) the uppermost portions 531 of the traces 530 are separated from each other in a non-uniform manner. More specifically, a first distance between the uppermost portions of the upper traces (e.g., traces 530a, 530b) is much less than a second distance between the lower traces 530 (e.g., traces 530g, 530h). In the Figure 13 illustrated embodiment, one or more of the distances by which the intermediate traces 530 (traces 530c, 530d, 530e, 530f) are separated differ from both the first distance and the second distance. In other words, the distance between the upper end portions of adjacent traces 530 increases with the distance from the upper surface of the seal strip 500, provided that in some cases, the distance from the upper end portion of one trace 530 to the upper end portion of its adjacent trace 530 can be the same (e.g., (i) the distance between traces 530a and 530b and (ii) the distance between traces 530b and 530c can be the same).

[0081] Furthermore, in the illustrated embodiment, the traces shown in solid lines (i.e., 530a, 530c, 530e, 530g) are located on one side of the PCB, and the traces shown in dashed lines (i.e., 530b, 520d, 530f, 530h) are located on the opposite side of the PCB. This arrangement can help keep the traces that are close to each other separated.

[0082] Those skilled in the art will appreciate that the sensing portion 522 of the wear monitoring system 520 can be connected to a signal processing portion that is similar to any of the signal processing portions 124, 224, or 324 in terms of the position of resistors and / or capacitors.

[0083] This arrangement of the trace line 530 can provide a certain degree of flexibility in use for the user. Bringing the upper part of the trace line 530 closer to the surface of the sealing strip can enable the user to detect initial wear very accurately. The user can choose to take immediate action (e.g., replace the sealing strip 500) when wear is detected. Alternatively, if the user is less concerned about initial wear, the trace line 530 with a wider spacing located further away from the upper surface can provide a "fail-safe" level of detection in cases where more wear is acceptable.

[0084] The foregoing is a description of the invention and is not to be construed as limiting thereof. While exemplary embodiments of the invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the invention. Accordingly, all such modifications are intended to be included within the scope of the invention as recited in the claims. The invention is defined by the following claims, and equivalents thereof are included therein.

Claims

1. A sealing strip and a wear monitoring system, comprising: A sealing strip having an upper surface; And A wear monitoring system, the wear monitoring system comprising: A sensing portion including a plurality of electrical traces, each of the electrical traces including an uppermost portion positioned at a certain depth from the upper surface of the sealing strip, wherein the depth of the uppermost portion of each trace is different from the depth of the uppermost portion of other electrical traces; and A signal processing portion electrically connected to the electrical traces, the signal processing portion including circuitry configured to detect an electrical signal from the traces and determine when the uppermost portion of the traces is damaged.

2. The system according to claim 1, wherein, The signal processing portion includes a plurality of capacitors, each capacitor being connected to a corresponding electrical trace.

3. The system according to claim 1, wherein, The signal processing portion includes a plurality of resistors, each resistor being connected to a corresponding electrical trace.

4. The system according to claim 3, wherein, Each of the resistors has the same resistance.

5. The system according to claim 3, wherein Each of the resistors has a different resistance.

6. The system according to claim 1, wherein The detected electrical signal is a voltage signal.

7. The system according to claim 1, wherein, The detected electrical signal is a current signal.

8. The system according to claim 1, wherein The uppermost portions of the electrical traces are regularly spaced apart from each other.

9. The system according to claim 1, wherein, The uppermost positions of the electrical traces are unevenly spaced apart from each other.

10. The system according to any one of claims 1-9, wherein, The sensing portion and the signal processing portion are disposed on a common printed circuit board (PCB).

11. The system according to claim 10, further comprising a temperature sensing system disposed on the common PCB.

12. The system according to claim 10, wherein, The uppermost portion of the electrical traces is disposed on the fingers of the common PCB, the circuitry is disposed on the main portion of the PCB, and the fingers are generally normal to the plane defined by the main portion.

13. The system according to claim 1, wherein Each uppermost portion is generally parallel to each of the other uppermost portions.

14. The system according to claim 1, wherein, Each uppermost portion is arcuate.

15. A sealing strip monitoring system, comprising: A sealing strip having an upper surface; A printed circuit board (PCB) having a first finger, a second finger, and a main panel; A wear monitoring system, the wear monitoring system comprising: A sensing portion including a plurality of electrical traces, each of the electrical traces including an uppermost portion generally parallel to the upper surface of the sealing strip and positioned at a certain depth from the upper surface of the sealing strip, wherein the depth of the uppermost portion of each trace is different from the depth of the uppermost portion of other electrical traces; wherein the uppermost portion of the electrical traces is located on the first finger; A signal processing portion electrically connected to the electrical traces, the signal processing portion including circuitry mounted on the main panel of the PCB and configured to detect an electrical signal from the traces and determine when the uppermost portion of the traces is damaged; and a temperature monitoring system at least partially mounted on the PCB.

16. The seal strip monitoring system according to claim 15, wherein, The first finger and the second finger are arranged to be generally parallel to the main portion of the PCB.

17. The seal strip monitoring system according to claim 15, wherein, The temperature monitoring system is at least partially mounted on the second finger.

18. The seal strip monitoring system according to claim 15, wherein, The uppermost portions of the electrical traces are regularly spaced apart from each other.

19. The seal strip monitoring system according to claim 15, wherein, The uppermost positions of the electrical traces are unevenly spaced apart from each other.

20. The seal monitoring system according to claim 15, wherein, Each uppermost portion is arcuate.

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