Micrometer with pressure sensor

Abstract

The invention relates to a micrometer with a pressure sensor. A micrometer further includes a pressure sensor that measures the pressure experienced by the spindle. The micrometer is configured to present an indication signal when the pressure data generated by the pressure sensor indicates that a pressure threshold has been reached. The indication signal may be visually or audibly presented. The micrometer may further include an automatic locking mechanism to hold the spindle in place when a pressure threshold has been reached.

Description

Technical Field

[0001] The present disclosure relates to measurement tools. Background Art

[0002] Conventional micrometers are used to measure the distance or length dimension of an object with very fine precision measurements. Micrometers are capable of being accurate to a range less than conventional human scale distances (such as 1 mm or less). Due to this, ensuring the accuracy of the measurement is highly desirable. When measuring an object, a conventional micrometer may be susceptible to overtightening, which may cause inaccurate measurements if overtightening induces deformation in the measured object. Therefore, it is desirable to have a micrometer that is less susceptible to the effects that cause inaccurate measurements. Summary of the invention

[0003] One aspect of the present disclosure relates to a micrometer including a frame having a body, a spindle, an ejector pin, an anvil, a displacement sensor, an indicator, and a pressure sensor. The spindle includes a distal end and a proximal end, wherein the proximal end is at least partially disposed in the body along a first axis at a port of the body. The ejector pin engages the proximal end of the spindle, wherein an axial position of the spindle along the first axis changes in response to rotation of the ejector pin. The anvil pin is disposed on the frame along the first axis and at a predetermined distance from the port. The displacement sensor generates displacement data indicating a distance between the anvil pin and the distal end of the spindle. The indicator presents information by outputting an indication signal. The pressure sensor generates pressure data indicating a pressure applied by the spindle to the ejector pin at the proximal end of the spindle. When the pressure data indicates that the applied pressure is greater than a threshold value, the indication signal is modified. In some embodiments, the indicator includes a display, and the indication signal includes a visual display signal. In some embodiments, the indicator includes a speaker, and the indication signal includes an audible display signal. In some embodiments, the indicator includes a light emitting diode (LED), and the indication signal includes an illumination signal suitable for the LED.

[0004] The above aspects and other aspects of the present disclosure will be explained in more detail hereinafter with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is a diagrammatic view of a micrometer with a pressure sensor.

[0006] Figure 2 is a diagrammatic illustration of a pressure sensor for use within a micrometer.

[0007] Figure 3 is an exploded diagrammatic illustration of the parts of a micrometer with a pressure sensor.

[0008] Figure 4 is a diagrammatic view of a micrometer having a pressure sensor during use with a workpiece. DETAILED DESCRIPTION

[0009] The illustrated embodiments are disclosed with reference to the accompanying drawings. However, it will be understood that the disclosed embodiments are intended to be merely examples that may be embodied in various forms and alternative forms. The drawings are not necessarily drawn to scale, and some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed are not to be construed as limiting, but rather as a representative basis for teaching those skilled in the art how to practice the disclosed concepts.

[0010] Figure 1 1 is an illustration of a micrometer 100 according to one embodiment of the teachings disclosed herein. Micrometer 100 includes a frame 101 having a body 103 and a flange 105. Body 103 includes an interior portion suitable for housing other components of micrometer 100, and a number of ports 107 that permit access to cavities within other components of the body. In the depicted embodiment, body 103 includes two ports 107 that form a passage 109. Other embodiments may include different configurations having different numbers of ports 107 or different arrangements or shapes of ports 107 without departing from the teachings disclosed herein.

[0011] The spindle 111 is at least partially disposed within the passage 109. An anvil 113 is positioned on the flange 105, the anvil being axially aligned with the spindle 111 along a first axis 115. The spindle 111 is adjustably positionable along the axis 115, and because the length of the spindle 111 is known and the relative position of the anvil 113 relative to the rest of the frame 101 is known, the distance therebetween comprises a micrometer measurement distance 117. The measurement distance 117 is a variable distance that corresponds to the position of the spindle 111 relative to the anvil 113 along the axis 115.

[0012] The spindle 111 is further coupled to an ejector pin 119 that provides an interface to a user for positioning the spindle 111 along the axis 115. Rotation of the ejector pin 119 about the axis 115 in the rotational directions 121 and 121' causes corresponding movement of the spindle 111 along the axis 115 in the displacement direction 123. In the depicted embodiment, the ejector pin 119 is screwed into the port 107 to both secure the ejector pin 119 to the frame 101 and also enable displacement of the spindle 111. Other embodiments may include alternative configurations without departing from the teachings disclosed herein. In the depicted embodiment, the micrometer 100 further includes a grip 125 to provide an ergonomic surface for the user to rotate the ejector pin 119 and to provide a handle for the user during operation. In the depicted embodiment, the grip 125 may also be used to apply a rotational force to the ejector pin 119, but other embodiments may include other configurations without departing from the teachings disclosed herein.

[0013] Since the relative position of the anvil 113 relative to the frame 101 is known, the measured distance 117 can be accurately determined. A displacement sensor 127 is disposed within the body 103, which generates data indicating the displacement of the spindle 111 relative to the anvil 113 based on the relative displacement of the spindle 111 relative to the threaded extreme within the body 103. The displacement data is provided to a processor 129, which is configured to interpret the displacement data and provide a human-understandable signal. In the depicted embodiment, the micrometer 100 also houses a memory 131 within its body, which provides operating instructions to the processor 129 and can be utilized in some embodiments to store data generated during use.

[0014] The micrometer 100 also stores a pressure sensor 133 within the body 103 that measures the pressure applied by the spindle 111 on the ejector pin 119 and generates pressure data indicative of the measurement. In measuring the pressure applied by the spindle 111 on the ejector pin 119, the pressure sensor 133 effectively measures the pressure applied to the distal end of the spindle 111 when the distal end of the spindle 111 is in contact with an object, such as an anvil 113 or an object or workpiece undergoing dimensional measurement. When the pressure data indicates that a predetermined threshold pressure level is reached or exceeded, the processor 129 generates an indicator signal that can be presented to a user via a presentation element of the micrometer 100. The indicator signal can be used to notify the user that the pressure threshold has been reached, and in the depicted embodiment, this can be presented as an indication that the measurement operation has found its accurate reading. Advantageously, the pressure threshold can be set to accommodate workpieces of the expected material type, and when contact is made between the workpiece and the spindle 111, the pressure between the two indicates that the measured distance 117 is accurate for the size of the workpiece being measured.

[0015] In the depicted embodiment, micrometer 100 includes several presentation elements, including a display 135, a light emitting diode (LED) indicator 137, and a speaker 139. Other embodiments may include only some of the display 135, the LED indicator 137, or the speaker 139 without departing from the teachings disclosed herein. Some embodiments may include different or additional presentation elements to present indicator signals to a user without departing from the teachings disclosed herein.

[0016] During normal operation, the display 135 can be used to present a human-readable signal that displays the value of the measured distance 117 in user-selected units and scale notations (e.g., distance measured in millimeters). However, once the pressure has reached the threshold, the display 135 can be used to display an indication signal that the pressure threshold has been reached. The indication signal can be displayed in place of the measured value, or can be displayed in tandem or alternating with the measured signal without departing from the teachings disclosed herein. In some such embodiments, the user can select the desired display behavior, and these user selections can be stored in the memory 131 for reference by the processor 129 during measurement.

[0017] In the depicted embodiment, once the pressure threshold has been reached, the LED indicator 137 may be illuminated to indicate the state. In the depicted embodiment, the LED indicator 137 may present different signals indicating different states. By way of example and not limitation, the illumination of the LED indicator 137 may include a flashing signal, steady-state illumination, pulse waveform illumination, or illumination using a plurality of different colors to indicate different states without departing from the teachings disclosed herein. In the depicted embodiment, the LED indicator 137 may be configured to remain unilluminated until the pressure threshold has been reached, and then may continuously flash with a single color. In other embodiments, the LED indicator 137 may be illuminated in different colors to indicate different pressures measured by the pressure sensor 133. By way of example and not limitation, the LED indicator 137 may be illuminated in green for zero or minimum pressure measurements, in amber for pressure measurements that are not within a specified range of the pressure threshold, and in red for pressure measurements that are at or beyond the pressure threshold. Other embodiments may utilize any combination of illumination modes and colors of the LED indicator 137 without departing from the teachings disclosed herein. In some embodiments, a user may select desired LED behavior, and these user selections may be stored in memory 131 for reference by processor 129 during measurements.

[0018] In the depicted embodiment, once the pressure threshold has been reached, the speaker 139 may present an audible indication signal to indicate the state. In the depicted embodiment, the speaker 139 may present different signal types that indicate different states, or to accommodate user preferences. By way of example and not limitation, the speaker 139 may emit an audible indication signal including a sine tone, a square wave tone, a triangle wave tone, a sawtooth tone, a noise tone, a burst of audible signals (such as a beep or chirp), an electric horn signal, or any other audible indication signal recognized by a person of ordinary skill in the art without departing from the teachings disclosed herein. In some embodiments, the characteristics of the tone may vary to indicate different pressures measured by the pressure sensor 133. By way of example and not limitation, a tone with a specified sine frequency may be emitted at different volume levels to correspond to different pressure measurements, wherein the speaker remains silent for zero or minimum pressure measurements, a "quiet" volume is used for pressure measurements within a specified range of the pressure threshold, and a "loud" volume is used for pressure measurements at or above the pressure threshold. Other embodiments may utilize any combination of audible signal patterns, frequencies, and volumes of the speaker 139 recognized by a person of ordinary skill without departing from the teachings disclosed herein. In some embodiments, the user may select the desired speaker behavior, and these user selections may be stored in the memory 131 for reference by the processor 129 during measurement.

[0019] The micrometer further includes several user-facing elements to enhance its usefulness during measurement operations. In the depicted embodiment, this includes a human machine interface (HMI) 141, which is suitable for providing input to the processor 129 to the user and controlling various aspects of the operation. In the depicted embodiment, the HMI 141 includes a plurality of buttons, but other embodiments may include other inputs without departing from the teachings disclosed herein. By way of example and not limitation, other such embodiments may include switches, soft keys, touch screen inputs, buttons, or any combination thereof without departing from the teachings disclosed herein.

[0020] HMI 141 provides the user with the ability to select user preferences for presentation elements, calibrate displacement sensor 127 and pressure sensor 133, or store or recall measurement data in memory 131. HMI 141 may additionally be utilized to change the units or scale of the display. In some embodiments, HMI 141 and display 135 may be utilized to permit the user to change the pressure threshold used during the measurement operation.

[0021] The processor 129 is in data communication with each of the other electrical components of the micrometer 100. In the depicted embodiment, the processor 129 is in data communication with each of the displacement sensor 127, the memory 131, the pressure sensor 133, the display 135, the LED indicator 137, the speaker 139, and the HMI 141 via a data connection (not shown). Other embodiments featuring different configurations or arrangements of elements may include different, fewer, or additional data connections without departing from the teachings disclosed herein. In the depicted embodiment, all of the electrical components of the micrometer 100 are powered via a portable power source (such as a battery (not shown)) stored within the body 103. Other embodiments may include electrical connections to an external power source to replace or supplement the portable power source without departing from the teachings disclosed herein.

[0022] Micrometer 100 additionally includes a lock 143. Lock 143 is adapted to prevent movement of spindle 111 along axis 115 in direction 123. Lock 143 may include a clutch, a lacing, a stop, a retaining pin, or any other retaining mechanism known to those of ordinary skill without departing from the teachings disclosed herein. In the depicted embodiment, lock 143 is engaged via a rotational motion that moves the relative orientation of lock 143 from an unlocked position to a locked position. Lock 143 may be disengaged by reversing the rotation back to the unlocked position. In the depicted embodiment, lock 143 includes an automatic lock 143 that communicates data with processor 129 via a data connection (not shown). In such an embodiment, processor 129 may automatically engage lock 143 in response to pressure sensor 133 indicating that a pressure threshold has been reached. The automatic locking function may be implemented using a solenoid, an electric actuator, an electric lever arm, or any other activation mechanism known to those of ordinary skill in the art for retaining mechanisms without departing from the teachings disclosed herein. In the depicted embodiment, the lock 143 requires manual disengagement, but other embodiments may include automatic or electronically controlled disengagement mechanisms without departing from the teachings disclosed herein.

[0023] Figure 2 is suitable for use in micrometers (such as Micrometer 100; see Figure 1) is an illustration of a pressure sensor 133 for use in an apparatus 100 and / or computer readable medium. The pressure sensor 133 includes a housing 201 that provides structural support for a capacitor matrix 203 that is connected at either end to one of a number of electrical leads 205. The capacitor matrix 203 holds an electrical charge, and the close proximity of the turns of the conductive elements of the capacitor matrix 203 generates a capacitive effect between the leads 205. By shifting the turns of the capacitor matrix relative to other turns, the capacitive effect is modified, thereby changing the charge seen between the leads 205. This change in charge produces a pressure measurement signal, and a properly calibrated processor is able to interpret the pressure measurement signal in response to the physical shifting of the turns of the capacitor matrix 203. In the depicted embodiment, the center of the capacitor matrix 203 may pass directly through a major axis (such as, major axis 111; see Figure 1 ) and additional surfaces (such as the surface of a pin to which the spindle is coupled, such as pin 119; see Figure 1 ) are displaced by contact between the spindle and the additional surface. Since the capacitor matrix 203 expands to increase the capacitive effect, the pressure sensor 133 generates a larger signal as the pressure between the spindle and the additional surface increases.

[0024] In the depicted embodiment, the frame 201 additionally includes a gap 207 adapted to permit passage of other physical components (such as the spindle 111; see Figure 1 ) to mount or thread the pressure sensor 133. Other embodiments may include other mounting configurations without departing from the teachings disclosed herein.

[0025] In the depicted embodiment, the pressure sensor 133 may include an operating scale suitable for use with workpieces of corresponding size. By way of example and not limitation, a larger workpiece may experience greater pressure on the measuring spindle and thus a less sensitive pressure sensor may be required or desired in a corresponding micrometer. In some embodiments, the pressure sensor 133 has a measurable pressure range of approximately 5 ounces of pressure and generates a pressure signal accurate to within half an ounce of pressure. By way of example and not limitation, the micrometer 100 (see Figure 1 ) may have a pressure threshold set to approximately 1 ounce of pressure with an accuracy range of ±0.5 ounces of pressure. In some embodiments, the micrometer may have a pressure threshold selected by the user without departing from the teachings disclosed herein.

[0026] Figure 31 is an exploded diagrammatic view of micrometer 100 illustrating additional components or facets of the micrometer. In the depicted embodiment, spindle 111 includes distal end 311 and proximal end 315 disposed opposite each other along the longest axis of spindle 111. Distal end 311 provides a measurement reference point between spindle 111 and anvil 113 that defines a measurement distance 117 (not shown; see FIG. 1 ) during a measurement operation. Figure 1 ). The spindle 111 is coupled to the ejector pin 119 at the proximal end 315 to enable control of the axial displacement of the spindle 111 during a measurement operation. In the depicted embodiment, the pressure sensor 133 is disposed between the proximal end 315 and the first coupling surface 317 of the ejector pin 119, but other embodiments may include other arrangements of the pressure sensor 133 without departing from the teachings disclosed herein. By way of example and not limitation, some embodiments include alternative or additional placement of the pressure sensor 133 between the second coupling surface 319 of the ejector pin 119 and the third coupling surface 325 of the grip 325, which defines a coupling boundary between the ejector pin 119 and the grip 325 when the micrometer 100 is fully assembled. Other embodiments may include different arrangements or configurations without departing from the teachings disclosed herein.

[0027] Figure 4 1 is an illustration of a micrometer 100 in use to determine a measured distance 117 corresponding to a dimension of a workpiece 400. In this arrangement, a spindle 111 is displaced into a body 103 and out of the body 103 along an axis 115 toward anvil 113. When the spindle 111 has been extended to a sufficient extent, a proximal surface 411 of the workpiece 401 contacts the spindle 111 while a distal surface 413 contacts the anvil 113. Due to Newton's third law of motion, this contact exerts pressure on the spindle 111, which is sensed by a pressure sensor (such as pressure sensor 133; see FIG. 1 ) inside the body 103. Figure 1 , Figure 2 , Figure 3 ) is measured. The pressure sensor generates pressure data indicative of the pressure measurement experienced by the spindle 111. When the pressure data indicates that the pressure has reached a predetermined threshold, an indication signal is presented to the user via the display 135, the LED indicator 137, and / or the speaker 139. In the depicted embodiment, the lock 143 includes an automatic lock, and when the pressure data indicates that the pressure threshold has been reached, the lock 143 automatically engages to prevent any further extension of the spindle 111 toward the anvil 113. Advantageously, the automatic engagement of the lock 143 maintains the spindle 111 in the correct measurement position, and additionally prevents the spindle 111 from making additional extensions, which may cause damage or deformation of the workpiece 401.

[0028] The pressure threshold can be adjusted to accommodate different workpieces. By way of example and not limitation, a workpiece composed of a ductile, compliant, flexible or soft material (such as a polymer, elastomer, textile, organic material such as leather, or composite material selected for its flexibility) may exhibit less rigidity than other materials having harder and more rigid properties (such as metals, semiconductors, ceramics, or composite materials selected for their rigidity). In this case, a smaller amount of pressure experienced by the workpiece 401 will damage one or more of its surfaces. Alternatively, the workpiece 401 exhibiting compliant or flexible properties will deform under pressure, resulting in inaccurate measurements. Therefore, using a pressure sensor with a threshold appropriately set for the size and composition of the workpiece 401 can advantageously provide a more accurate measurement of the workpiece size and reduce the risk of damaging the workpiece during measurement. Conversely, a higher pressure threshold can be used to measure larger workpieces or workpieces comprising more solid materials to ensure that accurate measurements are obtained via a firm contact between the surface of the workpiece 401 and each of the spindle 111 and the anvil 113.

[0029] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the disclosed apparatus and methods. Instead, the words used in the specification are words of description rather than limitation, and it should be understood that various changes may be made without departing from the spirit and scope of the present disclosure as claimed. The features of various implementing embodiments may be combined to form additional embodiments having the disclosed concepts.

Claims

1. A micrometer comprising: A framework having a body; a main shaft having a distal end and a proximal end, the proximal end being at least partially disposed in the body along a first axis at a port of the body; an ejector pin engaging a proximal end of the spindle, wherein an axial position of the spindle along the first axis changes in response to rotation of the ejector pin; an anvil disposed on the frame along the first axis and at a predetermined distance from the port; a displacement sensor that generates displacement data indicative of a distance between the anvil and a distal end of the spindle; an indicator configured to present information; and a pressure sensor that generates pressure data indicative of pressure applied by the spindle to the ejector pin at the proximal end of the spindle, in, When the pressure data indicates that the pressure is greater than a threshold, the indicator outputs an indication signal.

2. The micrometer according to claim 1, wherein: The threshold is 1 ounce of pressure.

3. The micrometer according to claim 2, wherein: The pressure sensor is accurate to within one-half ounce.

4. The micrometer of claim 1, further comprising a lock configured to hold the spindle in its current position when the lock is engaged.

5. The micrometer according to claim 4, wherein: The lock is an automatic lock configured to engage in response to the pressure data indicating that the pressure is greater than the threshold.

6. The micrometer according to claim 1, wherein: The indicator includes a display and a speaker, the indication signal includes a visual output and an audible output, the display is configured to present a visual output indicating when the pressure is greater than the threshold, and the speaker is configured to present an audible output indicating when the pressure is greater than the threshold.

7. The micrometer according to claim 1, wherein: The indicator includes a light emitting diode (LED) that illuminates when the pressure is greater than the threshold.

8. A micrometer comprising: A framework having a body; a spindle having threads, a distal end, and a proximal end, the proximal end being at least partially disposed in the body along a first axis at a port of the body; an ejector pin engaging a proximal end of the spindle, wherein an axial position of the spindle along the first axis changes in response to rotation of the ejector pin; an anvil disposed on the frame along the first axis and at a predetermined distance from the port; a displacement sensor that generates displacement data indicative of a distance between the anvil and a distal end of the spindle; an indicator configured to present information; and a pressure sensor that generates pressure data indicative of pressure applied by the spindle to the ejector pin at the proximal end of the spindle, in, When the pressure data indicates that the pressure is greater than a threshold, the indicator outputs an indication signal, and The indication signal includes a visual output.

9. A micrometer according to claim 8, wherein: The threshold is 1 ounce of pressure.

10. A micrometer according to claim 9, wherein: The pressure sensor is accurate to within one-half ounce.

11. The micrometer of claim 8, further comprising a lock configured to retain the spindle in its current position when the lock is engaged.

12. A micrometer according to claim 11, wherein: The lock is an automatic lock configured to engage in response to the pressure data indicating that the pressure is greater than the threshold.

13. The micrometer according to claim 8, wherein: The indicator further includes a speaker configured to present an audible output indicating when the pressure is greater than the threshold.

14. A micrometer comprising: A framework having a body; a spindle having threads, a distal end, and a proximal end, the proximal end being at least partially disposed in the body along a first axis at a port of the body; an ejector pin engaging a proximal end of the spindle, wherein an axial position of the spindle along the first axis changes in response to rotation of the ejector pin; an anvil disposed on the frame along the first axis and at a predetermined distance from the port; a displacement sensor that generates displacement data indicative of a distance between the anvil and a distal end of the spindle; an indicator configured to present information; and a pressure sensor that generates pressure data indicative of pressure applied by the spindle to the ejector pin at the proximal end of the spindle, in, When the pressure data indicates that the pressure is greater than a threshold, the indicator outputs an indication signal, and The indicator signal comprises an audible output.

15. A micrometer according to claim 14, wherein: The threshold is 1 ounce of pressure.

16. A micrometer according to claim 15, wherein: The pressure sensor is accurate to within one-half ounce.

17. The micrometer of claim 14, further comprising a lock configured to retain the spindle in its current position when the lock is engaged.

18. A micrometer according to claim 17, wherein: The lock is an automatic lock configured to engage in response to the pressure sensor generating data indicating that the pressure is greater than a threshold value.

19. The micrometer of claim 14, wherein: The indicator further includes a display configured to present a visual output indicating when the pressure exceeds the threshold.

20. The micrometer of claim 14, wherein: The indicator includes a light emitting diode (LED) that illuminates when the pressure is greater than the threshold.

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