Abstract
A devise that will increase an inductive proximity sensor's detection distance and detection position. The devise uses a housing in combination with a sensor and axially magnetized magnet and a target magnet to achieve the increased detection distance and position. The devise can be defined as universal because it allows different manufacturers and sizes of sensors to be used and calibrated. A treaded end section of the devise allows connection of standard conduit fittings.
Claims
1. An apparatus used to increase sensing detection distance of inductive proximity sensors comprising: an inductive proximity sensor; a housing for said sensor; an axially magnetized magnet mounted in said housing.
2. The apparatus of claim 1 wherein said housing comprises: a treaded bore for set screw; a straight bore for said axially magnetized magnet; a set screw for locking said sensor.
3. The apparatus of claim 1 further comprising: a pilot bore that can be machined for different diameter sensors.
4. The apparatus of claim 1 further comprising: a target magnet for interaction with said sensor.
5. The apparatus of claim 1 further comprising: a threaded hole for a conduit connector.
6. The apparatus of claim 1 further comprising: said sensor is a two wire inductive proximity sensor.
7. The apparatus of claim 1 further comprising: said sensor is a three wire inductive proximity sensor.
8. The apparatus of claim 1 further comprising: said sensor operates on AC or DC voltage.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a side and upright view of the devise that shows all the elements combined that are needed to create the current invention. All elements are within the main housing 2 except for target 4 which is to be mounted as the target. FIG. 1 also shows sensor 1 can detect the presence of target 4 at its face end.
[0012] FIG. 2 is a top view of the devise in combination but not showing target 4 as in FIG. 1. Dimension 11 shows minimal clearance.
[0013] FIG. 3 is a side and horizontal view that is identical to FIG. 1 except that element 4 is positioned laterally unlike FIG. 1. FIG. 3 shows that the devise will operate even though element 4 is not positioned at the face end of element 1.
[0014] FIG. 4 illustrates sensing distance differences between the current invention and a inductive proximity sensor alone. Element 13, is a target 4 as shown in FIG. 1. Top drawing 17, which is the current invention, shows the many different positions the devise will detect the target and element 14 shows the distance in inches of detection. Bottom drawing 18 shows only a sensor without the current invention. It can be seen that there is only one detection position and the distance is greatly reduced.
DETAILED DESCRIPTION
[0015] Detailed description of the present invention are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriate detailed system, structure or manner.
[0016] Referring to FIG. 1, the present invention will be described. Housing 2 can be seen to comprise all items that when assembled make-up the complete apparatus. It is a machined non-metallic material such as plastic, nylon, fiberglass or any other non-metallic material. Housing 2 is shown on FIG. 2, which is a top view of FIG. 1. Hole 6 is a threaded bore for sensor 1. Hole 12 is a machined thread size of ½ inch NPT. This thread is slightly larger than 6 and allows the current invention to be connected to a standard conduit connector. In the assembly process of the current invention, sensor 1 is threaded into hole 6 and because threaded hole 12 is a larger hole, sensor 1 is inserted past threaded hole 12 till it meets the threads in hole 6. Hole 6 is machined with threads to match sensor 1. Sensor 1 then is threaded into housing 2 and positioned correctly. It is important to note that different manufacturers of sensors will be positioned at different locations within housing 1. Therefore, by turning the sensor in the threads, the correct position can be attained. A better understand this procedure is as follows. When assembling a complete apparatus, all items are within or about the housing 2. Cable 8 is connected to a pilot light for visual indication. Target Magnet 4 is positioned at approximately 3 to 4 inches from the face of sensor 1. Sensor 1 is then adjusted within hole 6 in housing 2 till the pilot light turns on. Then, target 4 is removed to assure the pilot light turns off. Target 4 is then moved back to the original position. If the pilot light comes on, the process of positioning is complete and set screw 3 is tightened to prevent sensor 1 to move, thus assuring the assembled current invention is calibrated. The 3 to 4 inch distance referred to is just an average distance. Some sensors may meet and exceed this distance while others may not. Therefore, the 3 to 4 inch distance referred to cannot be an exact distance, although in most cases, it can be an average.
[0017] Turning now to hole 10 on FIG. 1, the threaded bore is machined for the thread size of set screw 3. Hole 10 is machined completely through the body of housing 2 and into the bore of hole 6. Therefore, when sensor 1 is inserted into housing 2 and calibrated, and set screw 3 is threaded into hole 10, set screw 3 will come in contact with sensor 1 and lock sensor 1 in place with housing 2. Hole 10 can only be a threaded bore and set screw 3 can only be a screw with machined threads. The thread size hole 10 depends only on the thread size of set screw 3. As was mentioned previously, sensor 1 can have different diameters and different thread sizes. Further, since the present invention will operate correctly with various diameters of inductive proximity sensors, it is obvious that hole 6 will be machined for these different diameters of sensor 1.
[0018] In FIG. 1, hole 9 is shown as a hole completely through the length of Item 2. This is a straight hole without threads. The purpose of this hole is so that magnet 7, can be press fit into hole 9. The diameter of the hole 9 is slightly smaller than magnet 7. The purpose of drilling hole 9 smaller than magnet 7 is to create a press fit for magnet 7. In the process of assembling, magnet 7 is pressed into hole 9 throughout the length of housing 2.
[0019] Further on FIG. 1, target 4 is shown as the target magnet. Target 4 is an axially magnetized magnet. Target 4 is not included within the assembled apparatus but rather a separate entity that is to be placed on the member of equipment that is being monitored for motion detection. Item 4 is needed for the invention operation and not connected internally to Item 2. To further clarify it should be obvious that Item 2 in its completed form contains Items 1, 3, and 7. Also, housing 2 needs to be machined for these items. Therefore, holes 6, 10 and 9 are the machined bores either with machined threads or straight bore. Cable 8 is only the cable from sensor 1.
[0020] In reference to target 4, it can be seen in FIG. 1 to be positioned at the face or detection area of Item 1. It should be noted that the current invention uses an target 4 that is ⅞″ in diameter by 1″ long axially magnetized magnet. Thus, in the foregoing examples of detection distance, it is to be understood that any reference to detecting distances are based on Item 4 having these dimensions. The target 4 dimensions are being used for reference to show how the current invention creates a longer detection distance. The current invention can use different sizes of target 4 to accommodate different applications for the end user and will effect detection distance.
[0021] In this example seen on FIG. 1, sensor 1 would detect target 4 and “turn on” or become active. The distance between target magnet Item 4 and Item 1 face is referred to as “detection distance”. If a standard inductive proximity sensor without the current invention was used, this distance would be a nominal distance as per the specifications of the sensor. As stated earlier, this distance is in the range of 0.125 to 1 inch. With the standard inductive proximity sensor incorporated within the current invention, this distance is increased to approximately 3.5 inches based on the size of target 4. Because target 4 may vary in size to the application of the end user, the current invention's detection distance can vary but in any case, it greatly increases detection distance over a standard inductive proximity sensor used without the current invention.
[0022] In FIG. 3 we can see target 4 is now positioned on the side of the current invention and not at the face as was seen in FIG. 1. As long as the distance is within the approximate 3.5 inches, the proximity sensor incorporated within the current invention will become active or “turn on”. Also, it should be understood that sensor 1 will become active as long as target 4, being within the detection distance, is placed other than at the face of sensor 1. FIG. 4 shows 13 as different locations of target 4. The blocks A, B, C, D and E represent target 4. Sensor 1 will become active if Item 4 is placed anywhere between Blocks A thru E within the detection distance. This is especially helpful in applications that do not permit direct alignment between target 4 and the face of sensor 1. It should be understood that FIG. 4 is only a representative showing multiple points that target 4 can activate sensor 1.
[0023] FIG. 2, which is an end view. Dimension 11 shows the distance between hole 6 and hole 9. As discussed previously, hole 6 is a threaded bore. Therefore, hole 9 straight bore needs to be as close as possible to hole 6 without interfering with the finished machined threads of hole 6. The actual placement of hole 9 cannot be defined in dimension of placement on housing 2 because of the various diameter sizes of sensor 1 that could installed. Of course, the dimension of hole 6 depends on the dimension of sensor 1. In any case, hole 9 and hole 6 need to be as close as possible without interfering with each ones finished machining.
[0024] FIG. 4 will give a comparison of a common inductive proximity sensor and the current invention. Reference 17 shows the current invention fully assembled with all the components. Reference 13 depicts target 4 in the various positions that sensor 1 can detect target 4 presence. Also, dimension 14 shows the detecting distance in inches. Reference 18 shows just a normal sensor without the current invention. Reference 13 which is target 4 is shown in the only position where a sensor without the current invention can detect its presence. Dimension 16 shows in inches the detecting distance.
SUMMARY OF THE INVENTION
[0025] The primary object of the invention is to provide an apparatus that extends the detection distance of inductive proximity sensors.
[0026] Another object of the invention is to provide an apparatus that extends the detection distance of inductive proximity sensors of various dimensions.
[0027] Another object of the invention is to provide an apparatus that extends the detection distance of two wire inductive proximity sensors.
[0028] Another object of the invention is to provide a magnet that is used as a target for the inductive proximity sensor within the apparatus.
[0029] Another object of the invention is to provide an apparatus that increases an inductive proximity sensor's sensing area
[0030] Another object is to provide machined threads in the housing so that different brands of sensors to be properly adjusted
[0031] Another object of the invention is to provide an apparatus that does not limit detection to one position
[0032] Another object of the invention is to provide an apparatus that can be connected to an industry standard conduit connector
[0033] Another object of the invention is to provide an apparatus that can use either two or three wire inductive proximity sensors
