US 20050281375 A1
An open beam x-ray diffraction system and method are provided including modular x-ray heads for being detachably connected to a base unit having a common drive assembly that shifts the heads in an arcuate path during an x-ray diffraction measurement operation. The heads can be tailored to different performance criteria depending on the needs of the measurement operation that is to take place. To this end, one of the heads can be a microhead that is adapted to take measurements from otherwise difficult to access surfaces, such as on the inside of tubular parts. Enhancements to the drive assembly for improved accuracy and speed are also disclosed.
1. A modular x-ray diffraction system for taking x-ray diffraction measurements from different parts, the x-ray diffraction system comprising:
a plurality of modular x-ray heads for being detachably connected to the base;
a common drive assembly associated with the base for shifting the head connected to the base in an arcuate path during an x-ray diffraction measurement operation; and
an adapter between the base and the x-ray heads for connecting and detaching the heads from the base to allow an operator to select the head to be used for a particular x-ray diffraction measurement operation.
2. The modular x-ray diffraction system of
3. The modular x-ray diffraction system of
4. The modular x-ray diffraction system of
5. The modular x-ray diffraction system of
6. The modular x-ray diffraction system of
a link for interconnecting the module to the controller for transmission of the head's predetermined operational characteristics to the controller.
7. The modular x-ray diffraction system of
8. The modular x-ray diffraction system of
9. The modular x-ray diffraction system of
a drive shaft gear and an output shaft gear that cooperate to transmit power from the drive shaft to the output shaft for shifting of the connected head in the arcuate path via the adapter with one of the gears being split and including gear portions that are rotatively biased relative to each other to minimize play between teeth of the drive shaft and output shaft gears.
10. The modular x-ray diffraction system of
a detector adjustment assembly for shifting the detectors between at least two positions associated with two different x-ray diffraction measurement techniques.
11. The modular x-ray diffraction system of
12. The modular x-ray diffraction system of
13. An x-ray diffraction apparatus comprising:
an elongate x-ray head for generating x-rays;
an emitter of the head for directing x-rays at a part from which x-ray diffractions measurements are to be taken;
detectors of the head that detect the diffracted x-rays; and
a detector adjust assembly including a shift member to which the detectors are mounted and an actuator for allowing the detectors to be shifted to different positions for employing different x-ray diffraction measurement techniques with the x-ray head.
14. The x-ray diffraction apparatus of
15. The x-ray diffraction apparatus of
16. The x-ray diffraction apparatus of
17. The x-ray diffraction apparatus of
This is a continuation of prior application Ser. No. 10/390,479, filed Mar. 17, 2003, which is hereby incorporated herein by reference in its entirety.
The invention relates to a system and method for measuring the strength-related characteristics of a part material using x-ray diffraction techniques and, more particularly, to a system and method that employ such techniques with parts of various sizes and configurations.
The use of x-ray diffraction techniques for measuring residual stresses in crystalline substances such as metal or ceramic materials is well-known. The general idea with the use of x-ray diffraction is to subject the material to the radiation of x-rays with the resulting sensed x-ray diffraction peak interpreted to arrive at a measurement of a strength related characteristic, i.e. stress, retained austenite, hardness of the part material, to show, for instance, the level fo fatigue in the material.
More particularly, the present invention relates to open beam type x-ray diffraction equipment that utilizes a cantilevered x-ray goniometer head having fiberoptic detectors carried toward the forward end of the head. In contrast, there are x-ray diffraction systems that are of a closed loop variety in the sense that the x-ray head is positioned at one location along a circular mount with the detectors spaced generally across from or diametrically opposite to the x-ray head along the circle mount with the part inserted in the space therebetween. In these systems, part size is limited due to this orientation of the x-ray head and detectors, and generally, coupons have to be taken from the part that is desired to be measured. With the open beam approach, coupons do not have to be cut out from parts since the x-ray head and detectors are integrated with each other. However, current open beam x-ray equipment still suffers from shortcoming as described below.
One such problem is that there is no open beam type x-ray apparatus that can perform these types of measurements on a wide variety of different parts and/or different materials or materials with different characteristics such as with respect to crystalline structure. Generally, the size of the goniometer or x-ray tube head relates to the power required for its operation. With greater power levels, the diameter of the x-ray tube is larger for heat dissipation purposes. The power for a goniometer head is selected to generate sufficient x-ray flux for the x-ray diffraction process to take place with particular materials or material characteristic.
The problem with the use of larger diameter x-ray heads for taking measurement is that with certain parts such as pipes and the like, it would be desirable for measurements to be taken of the material in the interior of the part. Depending upon the relative size of the inner diameter of the pipe and of the head on the x-ray diffraction apparatus, it may be physically impossible for the x-ray head to fit inside the pipe and take a suitable measurement. Also, where part surfaces are in confined areas such as in close confronting relation to each other as can be found on fillets of aircraft rotor disks at the roots of the rotor blades, set-up of the x-ray diffraction equipment to precisely direct the x-rays at the surface location from which a measurement is desired can be difficult, and is usually unwieldy where the large x-ray head itself has to be manipulated. Since current open-beam x-ray diffraction units have x-ray heads that are specifically tailored to a material or materials from which measurements are to be taken, many different sizes and types of x-ray diffraction units generally are necessary to take measurements on a wide range of different parts that are of different or materials or material characteristics, and/or having different configurations raising equipment costs accordingly. Thus, there is a need for an x-ray diffraction system and method that allow for greater flexibility in terms of the different types of parts and part geometries from which accurate x-ray diffraction measurements can be taken.
Another problem in using this equipment is the measurement precision that is desirable, and the issues this creates with the system's drive mechanism for pivoting or rotating the tube during a measurement operation. During x-ray measurement operations, the tube is typically pivoted to vary the position of the x-ray emitter or collimator from which x-rays are emitted toward the part to obtain more precise measurements by way of sampling techniques as opposed to keeping the tube and its collimator fixed relative to the part. As mentioned, the tube is generally cantilevered and is pivoted back and forth along a fixed arcuate rack by a motor drive including a pinion gear which pivots with the tube. In another configuration, the motor pivots the rack which is fixed to the tube. In both instances, the motor is also part of the cantilevered structure of the current x-ray diffraction units. Thus, current x-ray diffraction units have heavy cantilevered weights, particularly those having larger x-ray tubes. Since the x-ray diffraction techniques employed rely on distinguishing minute differences in the diffraction peaks and patterns of the detected x-rays, precision is required for pivoting the x-ray head. Inaccuracies can be created in present drive mechanisms with transmission belts that stretch and/or with backlash problems that occur between meshed gears due to play therebetween such as with the above-described rack and pinion arrangement. Therefore, there exists a need for a drive mechanism that provides for precision movements of the x-ray head for taking efficient and accurate measurements therewith.
Various part sizes and configurations pose yet another problem for standard x-ray diffraction measurement techniques in that the preferred measurement technique, d v. Sine2 ψ, cannot be used to measure all part configurations. When using this technique, the sensors are positioned such that they remain in a plane that is parallel to the plane of angular rotation of the head itself. This technique is the most accurate way to measure strength related characteristics of parts because of the geometrical relationship between the x-ray emitter, part, and sensors. However, this technique requires enough room to allow the head to oscillate back and forth without having the sensors hit the part itself. Therefore, there are situations where a different method of measuring, called d v. Sine2 χ, must be used. When using this technique, the sensors are in a position that is shifted by ninety degrees about the longitudinal axis of the emitter from the d v. Sine2 ψ configuration so that the sensors are generally aligned or parallel to the longitudinal axis of the x-ray tube. Then the head rotates as it normally does during x-ray diffraction measurements. This sensor configuration allows the user to take measurements in narrow places such as between the roots of blades. However, utilizing the d v. Sine2 χ technique requires a sacrifice in measurement accuracy. Currently, one has to switch x-ray diffraction apparati in order to change from one technique to another. Accordingly, an x-ray diffraction apparatus that has flexibility in terms of the measurement techniques it employs would be desirable.
In accordance with one aspect of the present invention, an x-ray diffraction apparatus is provided having x-ray or goniometer heads that are modular to allow them to be switched with one another to optimize the performance of the apparatus. In this manner, measurements can be taken from a wider spectrum of part sizes and configurations and of different part materials or material characteristics without requiring different x-ray diffraction unit by using the same base x-ray diffraction apparatus in conjunction with different modular heads that are selected according to the operating requirements for the part from which measurements are to be taken. For instance, if the part includes measurement sites that are difficult or impossible to access with standard larger size x-ray tubes such as pipe interior surfaces, a smaller x-ray head can be exchanged with a larger head and removably attached to the apparatus for taking x-ray diffraction measurements therewith. If a high power x-ray head is preferable due to part materials and/or geometry, then a larger x-ray head can be exchanged onto the apparatus for the smaller head. As is apparent, rather than having a different x-ray diffraction unit for each different head with the floor space and expense this entails, the present invention allows for a single base unit to be employed with different modular x-ray heads to allow them to be switched with one another to optimize the performance of the apparatus. Programmable modules can be associated with each head to transmit information to the base unit controller relating to the size and other operational and performance characteristics of the specific head including its x-ray detector system connected to the unit for proper operation thereof without the need to enter such information each time a head is exchanged.
The modular heads each have an x-ray tube, and emitter/sensor assembly, and an adapter portion for connecting the head to the base of the apparatus, and more particularly a cooperating adapter portion thereof. The head adapter portion may be a socket that connects to the base adapter portion in the form of a shaft of the base, the shaft being driven by a drive train and motor to shift the x-ray head as described further herein. In the preferred form, the socket is conical, and the shaft has a conical terminus for mating in the x-ray head socket. To positively fix the shaft in the socket opening, the shaft can include a keyway and the head adaptor may have a key which mates and releasably locks into the keyway to prevent relative rotation between the shaft and x-ray head detachably connected thereto. Alternatively, the key and keyway can be reversed with the shaft being keyed and the socket including a keyway.
Each x-ray tube head has an emitter or collimator which depends from the tube generally perpendicular to the tube longitudinal axis for directing x-rays down toward the part. An arc mount is provided for detectors at either end thereof, and the emitter collimator bisects the arc mount, as is the typical configurations for these emitter/sensor assemblies on current x-ray tubes. Accordingly, operation of the motor or the base unit rotates the output shaft adapter which, in turn, rotates the x-ray tube detachably connected to the unit shaft adapter via the socket adapter portion thereof. Thus, rotation of the head adapter portion and the tube attached thereto causes the collimator carried toward the forward end of the tube to shift along a predetermined arcuate path so that x-rays are directed at a region on the part from different angles of attack from the x-ray tube head. Although the x-ray head assembly is cantilevered forward from the base unit, the drive mechanism including the motor and drive transmission including the output shaft are all disposed in the base unit to minimize the cantilevered weight of the modular x-ray heads thus improving the accuracy of the movements thereof in contrast to the heavier prior x-ray heads that had their pivot drive mechanisms integrated at the head to be cantilevered as previously described.
In another aspect of the invention, an improved drive assembly is provided which includes an anti-backlash mechanism to provide precision shifting for the head upon operation of the drive motor. Such precision shifting enables more accurate x-ray diffraction measurements to be taken. The anti-backlash mechanism preferably employs a split gear that is associated with the drive train, and more specifically the adapter shaft assembly of the base drive unit. The gear is split axially into gear portions that have their corresponding teeth portions oppositely biased relative to each other. In this manner, the faces of the teeth of the split gear stay firmly engaged against the faces on the teeth of the motor drive shaft gear so as to substantially minimize any loose spaces or play therebetween. Alternatively, the split gear could be provided on the motor drive shaft for meshing with a gear on the output shaft assembly.
Unlike prior rack and pinion drive systems as previously described, the split gear avoids backlash that can occur in the prior drive systems when the motor changes direction when the x-ray head has reached the end of its travel along the rack at one end or the other thereof. The rack and pinion system causes inaccuracies to be introduced into the measurements that are taken by the x-ray head due to the play between the gears as the motor changes directions. In contrast, the present split gear keeps its teeth firmly engaged against the teeth faces of the motor gear even when the motor is changing directions toward the end of the arcuate travel path in one direction or the other. Accordingly, the present anti-backlash mechanism avoids the inaccuracies caused by the play between the gear teeth in the prior drive systems.
As previously mentioned, the modularity of the x-ray heads of the present x-ray diffraction apparatus enables x-ray heads of varying sizes and/or configurations to be employed on the same base unit. To this end, the heads can include sizes ranging from relatively large heads of, for example, approximately four inches in diameter, to extremely small or micro-heads which can be on the order of approximately one and one quarter inches down to three-eighths of an inch in diameter. The window in the tube aligned with the collimator that allows passage of the x-rays generated in the tube to the collimator is normally brazed to the tube material, e.g. stainless steel. However, the problem with utilizing an intermediate brazing material in the microtube is that it increases the chances for melting which increases the potential for contaminating the tube and generating leakage from the tube. Accordingly, the preferred window utilized with the microtube x-ray head is electron-beam welded to the tube material to avoid intermediate brazing material.
Another adaptation for the microtube is the use of a flexible circuit board that receives signals from the detectors for processing thereof. The flexible circuit board can conform to the curved surface of the microtube x-ray head so as to avoid significantly increasing the diameter thereof. Generally, with prior larger x-ray tubes, the detectors are connected by fiber-optic cabling to a processor unit mounted toward the back of the x-ray head or thereabove thus creating impediments for maneuvering the head such as may be required for difficult part geometries. Accordingly, the use of the flexible circuit boards on the microtube maintains its enhanced flexibility in reaching hard-to-access target surfaces on parts from which x-ray diffraction measurements are to be taken.
In the other larger heads in the modular x-ray head set that can be employed with the present modular x-ray diffraction apparatus, another advantageous feature that can be implemented is the ability to shift the emitter/sensor assembly relative to the x-ray head so that both principle mathematical techniques, d v. Sine2 ω and d v. Sine2 χ are available to be utilized. While the modularity of the x-ray heads provided in the preferred system herein allows for the different emitter/sensor configurations to be fixed on different tubes that can be easily changed out depending on which measuring technique is to be utilized, the shifting of the emitter/sensor assembly on a particular tube is preferable from a convenience standpoint to avoid having to exchange tubes as has been described.
Typically, the emitter/sensor sub-assembly includes an arc to which the sensors are mounted as previously described. With the sensors in the d v. Sine2 ψ orientation, they are offset on either side of the tube longitudinal axis, and thus can serve as impediments to tube maneuverability when measuring difficult part geometries. Accordingly, by allowing for the shifting of the sensor arc so that it is in the d v. Sine2 χ orientation with the sensors aligned along the tube axis, the x-ray head can be better positioned as the arc is now in a minimally invasive orientation thereof, albeit invoking the mathematical technique that is less precise for x-ray diffraction purposes.
In one form, a manual actuator is provided which allows an operator to manually adjust the position of the sensors between the above-described configurations. The manual actuator can be a pin that is biased into a selected one of two apertures corresponding to the configuration for the sensors that is desired. The pin includes a handle pull ring to allow a user to pull it out from the aperture against its bias for shifting of the sensors to the other configuration. With the pin aligned with the other aperture, the pull ring is released and the pin is biased into the aligned aperture to fix the sensors in the selected configuration. Accordingly, the pull ring manual actuator allows for very efficient and quick adjustments to be made to the sensor configuration to allow the larger x-ray heads to be more flexibly employed with a variety of different part configurations.
Referring initially to
To allow different x-ray generator tube heads or head assemblies (see
The output shaft adaptor portion 26 and the socket adaptor portion 28 may be provided with a conical or frustoconical configuration so that they mate together with the conical surfaces in close fitting relation with each other to provide ease in alignment in making the connection for the adapter 24 herein. Rotation of the output shaft adaptor portion 26 is generated by operation of the drive assembly 18 for shifting the tube head 12 in its arcuate path 22. For this purpose, a key and keyway connection can be provided in the adapter 24 as by an axially extending key projection 30 formed on the adapter shaft 26 that can fit into an axial recess 31 formed in the socket 28 when angularly aligned therewith. In this manner, the output shaft adaptor portion 26 is non-rotatably received in the socket 28 for transmitting torque from the drive assembly 18 to the tube head 12 so that it is oscillated in its arcuate path 22 with motor operation.
The provision of modular x-ray generator head assemblies allows the different heads to be tailored for different part and material requirements for taking x-ray diffraction measurements therefrom. It is currently envisioned that the x-ray heads can be provided in different sizes and configurations such as shown in
Beyond size, the modular heads can be tailored in several other respects as well. For example, the wavelength generated for the x-rays can be tailored to the material to be measured so as to better match the lattice structure thereof. To do this, the material for the target anode 36 at the forward high voltage end in each of the tube heads can be varied. Exemplary anode materials can include copper, cobalt, wolfram, silver, molybdenum, manganese, iron and titanium. The beam shape can be tailored to the piece to be measured as by providing different collimators 20 on the various x-ray heads. For example, for those pieces that have surfaces in long narrow crevices or holes that are desired to be measured, the collimator 20 can be configured to generate a narrower x-ray beam to avoid measurement errors.
In addition to the collimator, an x-ray detector assembly 37 is provided as carried by each of the x-ray heads including x-ray detectors or sensors 38 and 40 that are typically mounted on either side of the collimator 20 via an arcuate x-ray mount 42. The x-ray heads can have the position of these detectors 38 relative to the collimator 20 varied along the mount 42 or on differently sized mounts 42 from one head to the other so that they are matched with the x-ray wavelength generated by the head and the response of the material for which the x-ray head is to be used for taking x-ray diffraction measurements from. The mount 42 itself can be shifted to provide for different measurement techniques or to accommodate different diffraction angles such as in assembly head 200, as will be discussed hereinafter. As is apparent, the provision of modular x-ray heads such as x-ray heads 12, 32, 34 and 200 enables much greater flexibility in tailoring the apparatus 10 to the particular needs of the x-ray diffraction operation that is to take place without necessitating several different x-ray diffraction units for this purpose.
Another feature of the preferred modular x-ray head apparatus 10 is the use of an electronic control system that includes a programmable module 43 associated with each of the x-ray heads 12, 32, 34 and 200, a controller 44 associated with the base unit 14, and an electrical link 46 that can interconnect the module 42 to the controller 44 with a selected one of the heads detachably connected to the unit 14. As can be seen in
The module 43 can include programmable memory so that it can be preprogrammed with information relating to the particular x-ray head with which it is carried. For example, the x-ray heads can be specifically tailored to measure a specific type of material or material characteristic as by generating an appropriate amount of x-ray flux and x-rays in the wavelength necessary for obtaining diffraction measurements from the part to be measured therewith. Thus, when x-ray head installation is successful, the controller 44 will have information or system configuration data transmitted thereto such as relating to the particular x-ray head that is attached to the base unit 14 such as the size of its collimator 20, the material type of its anode 36, as well as the size of the x-ray tube head itself and its power rating. For example, with the three different sizes of x-ray heads 12, 32 and 34 discussed herein, each can have different power ratings correlated to their size. Accordingly, the large x-ray head 12 may have a diameter of approximately four inches and a power rating of 3000 watts, the intermediate x-ray head 32 may have a diameter of approximately 1½″ and a power rating of 300 watts, and the micro x-ray head 34 may have a diameter of approximately one and one quarter inches down to approximately three-eighths of one inch and a power rating of 200 watts or less. In addition, the power requirements for a particular size of tube head can be varied such as when there are heads of the same size that have different target anodes 36 from each other. In each instance, the control system will be provided the power rating of the particular modular x-ray head that is connected to the base unit 14 via the electrical connection 46 provided between the programmable module 42 and the controller 44. Once such information is received, the controller 44 regulates power supply to enable operation of the x-ray head in accordance with the power rating thereof.
Other variables between the x-ray heads which can be transmitted as data information to the controller 44 include the focal distance of the x-ray head and the details of the x-ray detector system 37 such as detector type or number of detectors, detector width and resolution provided by the detectors. Also, if the x-ray head employs a detector configuration that is fixed, the module 42 associated therewith can be programmed to indicate the measurement technique to be employed by the control system as dictated by the predetermined fixed detector configuration.
The small or micro tube x-ray head 34 disclosed herein can include alternative cooling systems provided therefor. Referring to
Another adaptation for the microtube 34 in particular resides in the use of a flexible circuit board 64 including a circuit 66 printed thereon that processes signals received from the detectors 38 and 40 on either side of the collimator 20. In prior x-ray heads, the detectors include cabling that extend therefrom generally upwardly to a control unit for processing x-ray signals which restricts the maneuverability of these heads and their ability to access confined spaces. On the other hand, with the flexible printed circuit board 64 herein, only a very short length of fiberoptic cable 68 extending between the detectors 38 and 40 and the circuit board 64 need be provided as the board 64 can be secured to the outer surface of the tubular housing 54 toward the end 62 thereof in close proximity to the detectors 38 and 40 and in substantial conformance therewith wrapped about the housing 54. In this manner, the effective diameter of the tubular housing 54 is only nominally increased as by the thickness of the thin printed circuit board 64 with the attendant advantage of removing the impediments caused by having large and long lengths of cabling extending up from the detectors 38 and 40 to a fixed processing unit above the x-ray head as in prior systems. Accordingly, with the present flexible circuit board 64 including circuit 66 adapted for processing the x-ray detector signals, the length of the detector cables is minimized as it extends only for the distance between the detectors 38 and 40 mounted to the integrated arc mount 41 at either end thereof to the outer surface of the tubular housing 54 to which the circuit board 64 is secured. As can be seen in
As shown in
Referring next to
The carrier support 206 can have a generally U-shaped configuration opening downwardly toward the part 204 from which x-ray diffraction measurements are to be taken with the x-ray tube 200 a provided with an overhead support generally above and off to one side of the part. More specifically, the support 206 includes a rear, vertically extending portion 208 which includes the socket adapter portion 28 toward the bottom thereof. Toward the upper end of the vertical portion 208, there is a forwardly extending portion 210 including a hanger 212 that supports the x-ray tube 200 a forwardly of the rear support portion 200 a and below the upper portion 210.
Frame portions 208 and 210 and hanger 212 include an adjustable mounting therebetween as by adjustment slots 214 and associated guide fasteners that allow the tube head 200 a to be vertically adjusted in the z-axis direction and adjusted in the fore and aft x-axis direction. In addition, head assembly 207 includes an upwardly extending flange 218 that has followers 220 for being adjustably secured in an arcuate guide slot 222 of the hanger 212 to provide for arcuate adjustments of the head 207 in a compound x and z axis angular direction. By way of the adjustability provided by the carrier support 206, the position of the collimator 20 can be adjusted to allow for the angle of attack of the x-ray beam emitted therefrom to be varied relative to the part 204, and specifically the throughbore 202 having its axis 202 a extending in the x-axis direction. In this manner, the optimum orientation of the tube 200 a and collimator 20 thereof can be achieved relative to the configuration and size of the through bore 202.
Similarly, the detector assembly 37 can be adjustably supported by the carrier support 206, and specifically via a forward, downward extension 224 thereof. As shown, the extension 224 projects downwardly from the front end of the upper support portion 210 with the detector assembly 37 including the arc mount 42 thereof being adjustably secured to slotted slide bracketing 226 to position the detectors on the side of the part 204 opposite to the side at which the tube 200 a and collimator 20 are disposed. The slide bracketing 226 can allow for x, y and z adjustments of the detector assembly 37, as can be seen in
As previously mentioned, the drive assembly 18 for oscillating the x-ray heads in their arcuate path 22 during an x-ray diffraction measurement operation is integrated into the base unit 14 rather than being integrated with the x-ray head assembly and cantilevered forwardly along with the heads from the base unit 14 as in prior x-ray diffraction systems. In this manner, the weight of the drive 18 does not affect the x-ray diffraction measurement operation either in terms of its speed or its accuracy unlike prior systems. As shown, the present x-ray head drive assembly 18 includes a motor 72 that is mounted to the base unit 14 as by bracket 74. The motor 72 includes a drive shaft 76 which transmits rotary power to the output shaft assembly 77 including end adaptor portion 26 thereof. In the illustrated and preferred form, the drive assembly 18 includes worm gear transmission drive 78, as shown best in
To minimize measurement inaccuracies caused by backlash, the above-described worm gearing 78 is provided with an anti-backlash mechanism 84, as can be seen in
The gear portion 88 is mounted to the shaft portion 94 so as to freely rotate with respect thereto. As shown in
Accordingly, the preferred and illustrated anti-backlash mechanism 84 includes a worm wheel gear 82 that is split axially into two annular gear portions 86 and 88 that are angularly or rotatably preloaded or biased relative to each other so as to maintain positive contact between the gear teeth 82 a of the split-gear 82 and the gear teeth 80 a of the gear 80, as is shown schematically in
The micro tube 34 can have its detectors 38 and 40 fixed either as shown in
Referring now to
Accordingly, the detector adjust assembly 122 obviates the need to provide a different x-ray head for each of the two measurement techniques. Although the assembly could be implemented with the microhead 34, it has been found that to obtain the maximum benefits of the reduced size of the head 34, it is preferred to provide two versions thereof as shown in
The detector adjustment assembly 122 can include a manual actuator such as in the form of a pull ring assembly 124 that allows an operator to manually adjust the position of the detector assembly 37. More specifically, the assembly 122 includes a shift member in the form of a rotary disk 126 having the detector mount 42 fixed thereto. The rotary disk 126 can be secured in a selected one of two different positions relative to disk mount member 128 thereabove with the two positions corresponding to the two x-ray diffraction measurement techniques discussed herein. To this end, the disk mount member 128 includes a pair of apertures 130 and 132 that are spaced 90 degrees from each other to correspond to the d v. Sine2 ψ and d v. Sine2 χ measurement techniques, respectively.
The rotary disk member 126 carries a plunger member 134 of the pull ring assembly 124. The plunger member 134 is spring loaded in through bore 136 formed in the disk member 126. The through bore 136 can be aligned with either one of the apertures 130 and 132 to fix the position of the detector system 37 as desired. Referring to
As shown in
Turning to more of the details, each of the x-ray heads 12, 32 and 34 are mounted to a carrier support 150 that extends rearwardly from the x-ray head housing to depending flange mount portion 152 at the rear end thereof. The rear flange mount portion 152 includes the socket adapter portion 28 which is configured identically for each head and carrier support 150 thereof including for head 200 and its previously-described carrier support 206. Each carrier support 150 includes a forwardly extending cantilevered support portion 154 which carries the heads 12, 32 and 34 thereon such that their respective longitudinal axes 12 b, 32 b and 34 b extend generally in the fore and aft x-axis direction offset from the socket axis 28 a and spaced thereabove. In this manner, operation of the common drive assembly 18 causes the heads 12, 32 and 34 and their collimators 20 to traverse or sweep through the arcuate path 22 which is centered on the offset axis 28 a of the socket adapter 28 of each of the heads. Similarly, the socket axis 28 a will generally be offset from the tube 200 a of head assembly 200 so that operation of the drive assembly 18 causes its collimator 20 to traverse arcuate path 22. Together, the shaft adapter portion 26 and the socket adapter portion 28 cooperate to align each head in the same predetermined position each time one is connected to the base unit 14. Accordingly, with the any of the heads 12, 32, 34, and 200 detachably connected to the base unit 14, the shaft adapter axis 26 a will be aligned with the socket axis 28 a to provide consistent and repeatable positioning of the modular x-ray heads herein.
Continuing reference to
Referring next to
While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.