Ultrasonic measuring device for industrial measuring device

Abstract

An ultrasonic measurement apparatus for an industrial measurement device is described. The apparatus comprises: a base (20) comprising an ultrasonic transducer driver (29); and an elongate rod (22) comprising an ultrasonic transducer (33). A connector assembly releasably attaches the elongate rod (22) to the base (20). The connector assembly has a first connector portion (28) disposed on the base (20) and a second connector portion (36) disposed at the proximal end of the elongate rod (22). The first and second connector portions (28, 36) when connected provide mechanical alignment of the elongated rod (22) relative to the base (20) and electrical connection between the ultrasonic transducer (33) and the ultrasonic transducer driver (29). The connector assembly also includes a coaxial electrical connector (44, 46) that provides an electrical connection between the ultrasonic transducer (33) and the ultrasonic transducer driver (29) and also allows the elongate rod (22) to be secured to the base (20) in any rotational orientation about the longitudinal axis (50) of the elongate rod (22). In this manner, a compact arrangement can be provided in which the elongated rod (22) can be easily attached to and detached from the base (20).

Description

[0001] The present invention relates to an ultrasonic measuring device for industrial measuring equipment such as machine tools and in particular to such an ultrasonic measuring device having a base to which an elongated rod comprising an ultrasonic transducer can be attached.

[0002] It is known to use ultrasonic equipment to measure industrially manufactured parts, such as turbine blades, engine components, etc. Such ultrasonic measurements can be used, for example, to measure the thickness of such parts or to identify defects within these parts. Ultrasonic equipment is usually handheld and allows manual ultrasonic inspection by a trained operator, but automated industrial ultrasonic inspection systems are also known. For example, ultrasonic measurement equipment is known that can be mounted to industrial measurement devices such as computer numerical control (CNC) machine tools or coordinate measuring machines (CMM). Such devices allow automatic inspection of parts before, during or after the machining process.

[0003] WO 2016 / 051147 describes an ultrasonic measurement device that is attached to a CMM via a two-axis rotating head that allows fine adjustment of the angle of the ultrasonic probe relative to the surface of the object. The ultrasonic device of WO 2016 / 051147 is modular and comprises a base portion housing a transducer to which a passive coupling module can be attached and detached in an automated manner, the passive coupling module comprising a self-lubricating hydrophilic elastomeric ball housed in a shell.

[0004] WO 2021 / 038106 describes an ultrasonic device that can be mounted to the spindle of a machine tool to allow in-process ultrasonic measurement. A corresponding ultrasonic measuring device is also sold by Hexagon AB of Stockholm, Sweden under the product name RWP20.50-G-UTP. Figure 1 In the first embodiment described in FIG. 2 and FIG. 3 , a measuring instrument attachable to a tool holder of a machine tool is described (respectively in WO 2021 / 038106 and Figure 1 2 by reference numerals 9 and 22). The measuring instrument is linked to a transmitting and receiving unit 11 outside the machine housing by a wireless (radio or optical) signal line 18. An ultrasonic measuring unit (referenced 23) is attached to the measuring instrument by a threaded connection, and an electrical link is provided between the measuring instrument and the ultrasonic measuring unit.

[0005] The inventors have recognised that the arrangement described in WO 2021 / 038106 has various disadvantages. For example, the provision of two housing parts (i.e. separate housing parts forming the measuring instrument and the ultrasonic measuring unit, respectively) makes the entire arrangement rather bulky, thereby hindering or preventing rapid measurement of smaller objects or objects with surfaces having restricted access (such as holes etc.), and also requires replacement of the entire ultrasonic measuring unit if a different ultrasonic configuration is required.

[0006] US 6189384 describes a handheld ultrasound monitoring system in which an ultrasound sensor can be mechanically and electrically connected to a housing via a multi-pin connector. US 2015 / 0177193 describes a thickness gauge in which the sensor head is removable from a mobile handheld unit. US 2009 / 0255352 describes a handheld non-destructive testing system having a connector for attaching a probe head to a flexible shaft. The connector of US 2009 / 0255352 includes a LEMO connector that allows multiple electrical connections to be established. CN 109620296 describes a medical imaging device (i.e., not a device for industrial measurement) in which a connector provides mechanical, electrical and optical connections.

[0007] According to a first aspect of the present invention, there is provided an ultrasonic measuring device for an industrial measuring device, the ultrasonic measuring device comprising:

[0008] a base, the base including an ultrasonic transducer driver,

[0009] an elongated rod including an ultrasonic transducer, and

[0010] a connector assembly for releasably attaching the elongated rod to the base, the connector assembly comprising a first connector portion disposed on the base and a second connector portion disposed at the proximal end of the elongated rod, the first connector portion and the second connector portion providing mechanical alignment of the elongated rod relative to the base and electrical connection between the ultrasonic transducer and the ultrasonic transducer driver when connected,

[0011] Characterized in that the connector assembly includes a coaxial electrical connector that enables an electrical connection to be established between the ultrasonic transducer and the ultrasonic transducer driver, wherein the elongated rod is fixedly connected to the base in any rotational orientation about the longitudinal axis of the elongated rod.

[0012] Therefore, an ultrasonic measuring device is provided, which is configured to be used with an industrial measuring device. Such an industrial measuring device may include a dedicated measuring machine (e.g., a coordinate measuring machine or a robot) or a machine tool (e.g., a cutting machine or a milling machine), which also processes (e.g., cuts or mills) the part to be measured. It should be noted that industrial measurement refers to the measurement of industrially manufactured objects. For example, industrial measurement may include the measurement of the thickness of a manufactured part (e.g., a metal part) or the detection of defects in such a manufactured part. For the avoidance of doubt, industrial measuring devices do not include medical ultrasound devices for measuring or imaging the human or animal body (such as described in CN 109620296).

[0013] The ultrasonic measuring device includes a base from which an elongated rod extends. The base can also be attached to an industrial measuring device. For example, the base can include a tool handle that allows the base to be releasably attached to a tool bracket disposed on a spindle of a machine tool. The elongated rod includes an ultrasonic transducer that can be used to transmit and / or receive ultrasound. For example, the ultrasonic transducer can allow defect detection or thickness measurement of industrially produced parts. An ultrasonic transducer driver disposed in the base includes electronic devices that drive the ultrasonic transducer (e.g., transmit and / or receive ultrasound) during use.

[0014] The elongated rod can be releasably attached to the base via a connector assembly. Therefore, in use, the elongated rod is attached to the base by the connector assembly. The connector assembly is formed by two mutually engageable parts or connector parts. The first connector part is arranged on the base, and the second connector part is arranged at the proximal end of the elongated rod. In other words, the base includes a first connector part, and the elongated rod includes a second connector part. The connector assembly is arranged so that when the first connector part and the second connector part are connected to each other, the elongated rod is mechanically aligned with respect to the base. For example, the longitudinal axis of the elongated rod can be aligned with the central axis of the base part. In addition, the connector assembly also provides an electrical connection between the base and the elongated rod, which allows an electrical connection to be provided between the ultrasonic transducer and the ultrasonic transducer driver. Therefore, the electrical connection electrically connects the transducer to the transducer driver, thereby allowing the transducer driver to transmit a signal to the ultrasonic transducer and / or receive a signal from the ultrasonic transducer. In other words, the connector assembly provides both mechanical coupling and electrical connection between the base and the elongated rod.

[0015] The connector assembly includes a coaxial electrical connector that provides the necessary electrical link between the ultrasonic transducer and the ultrasonic transducer driver. This arrangement enables the elongated rod to be fixedly connected to the base in any rotational orientation around the longitudinal axis of the elongated rod. In other words, the rotational orientation of the elongated rod relative to the base is not subject to the restriction or constraint that the complementary electrical contacts (e.g., pins / orifices) must be ensured to be rotationally aligned relative to each other. The ability to connect the coaxial electrical connector in any rotational orientation means that the rotational orientation of the elongated rod relative to the base that can be adopted is not limited. Importantly, this allows the elongated rod to be mounted to the base in any desired rotational orientation when it is mounted to the industrial measurement device. This makes it easier for the operator to attach the elongated rod to the base, especially when the position where the base is mounted to the machine tool limits the visibility or accessibility of the connector, because there is no need to carefully align the rotational orientation of the elongated rod relative to the base. This also allows the rotational orientation of the elongated rod to be appropriately selected. As explained in more detail below, in some embodiments, the elongated rod may be asymmetric (eg, curved or dog-legged, etc.), and the ability to select the angular orientation of the elongated rod for such an arrangement may allow for automated collection of measurements from surfaces having different orientations.

[0016] The handheld devices of US 6189384, US 2015 / 0177193, US 2009 / 0255352 and CN 109620296 do not include such a coaxial electrical connector (i.e., the connectors of such prior art devices require a unique rotational alignment to achieve mutual engagement), and the operator does not need such a coaxial connector to align such a device with the object being inspected (i.e., because the rotational orientation can be adjusted manually). In addition, unlike the arrangement described in WO 2016 / 051147 where the (passive) coupling module is replaceable, the device of the present invention allows the elongated rod including the ultrasonic transducer to be removed and reattached. Therefore, the present invention allows the elongated rod to be replaced quickly and easily. For example, the elongated rod can be replaced with an elongated rod of different length, an elongated rod with different transducer types, an elongated rod with different coupling elements for acoustically coupling to the surface of the object to be inspected, or an elongated rod with different holders for holding such coupling elements. A rod extension member may also be located between the base and the elongated rod, as described in more detail below.

[0017] The arrangement of the present invention also provides various advantages over the ultrasound device described in WO 2021 / 038106. For example, the removable attachment of the elongated rod via the connector assembly allows a variety of elongated rods to be quickly and easily attached to the base portion. Importantly, although such elongated rods include transducers, the same transducer driver of the base can be used with each such elongated rod. This reduces the cost of reconfiguring the measurement device for different types of measurements (e.g., to provide rods of different lengths or different types of ultrasound transducers) and can also provide a more compact arrangement.

[0018] Advantageously, the first connector portion comprises a first reference surface and the second connector portion comprises a second reference surface. The engagement of these first reference surfaces and the second reference surface provides an orientation alignment of the elongated rod relative to the base when the first connector portion and the second connector portion are connected. In other words, the mechanical alignment of the elongated rod with the base is defined by the interaction of the first reference surface and the second reference surface. The first reference surface and / or the second reference surface may be flat surfaces that provide an alignment of the elongated rod relative to the base when engaged. The first reference surface and the second reference surface may be substantially rigid. In this way, the elongated rod may be attached to the base in a known and repeatable orientation.

[0019] It should also be noted that the base may include a movable joint. The first connector part may then be attached to the rest of the base via the movable joint. For example, the base may include a housing and a movable joint, the first connector part being attached to the housing via the movable joint. The movable joint may allow the first connector part and therefore any attached elongated rod to move (e.g. tilt or slide) relative to the housing. If such a movable joint is provided, the movable joint may define a rest position without applying external forces. The elongated rod may then be movable away from the (predefined) rest position to allow the elongated rod to be aligned with the surface of the object to be measured.

[0020] The elongated rod may have any suitable shape. The elongated rod may include an elongated tubular member; for example, the elongated rod may be provided in the form of a tube or a tubular sleeve. The elongated rod may be substantially straight. The elongated rod may be rigid. The elongated rod may be substantially non-flexible. The elongated rod may not be straight. For example, the elongated rod may include an angled joint, a kink, a bend, or a dog-leg connection. The ability to control the rotational orientation of a non-straight rod has the advantage of allowing the distal end of the rod to be aligned with the surface to be measured. At least a portion of the elongated rod may be hollow or include a hollow lumen. The elongated rod may have any suitable cross-sectional profile, such as a square, rectangular, or elliptical cross section. Advantageously, the elongated rod has a substantially circular cross section. The length of the elongated rod may be at least 5 times its radius. The length of the elongated rod may be at least 10 times its radius. The radius of the elongated rod may be less than the radius of the base. The radius of the elongated rod is preferably less than half the radius of the base. The elongated rod may include a single part or tube (i.e., the elongated rod may be provided as an integral component). Alternatively, the elongated rod may be formed from multiple segments (e.g., multiple tubular segments). The segments may be permanently attached (e.g., bonded) to each other. Alternatively, such segments may be releasably attached to each other to allow the segments to be removed or replaced as needed. The ability to disassemble the elongated tubular rod may be advantageous for maintenance or repair purposes.

[0021] An ultrasonic coupling element for acoustic coupling with an object may also be provided at the distal end of the elongated rod. An ultrasonic transducer assembly including an ultrasonic transducer and an ultrasonic coupling element may then be provided. For example, the ultrasonic transducer may be placed in physical and acoustic contact with the transducer contact (rear) surface of the ultrasonic coupling element. This physical contact may be direct, or it may be indirect (e.g., via an intermediate component, such as an adhesive). Thus, the ultrasound generated by the ultrasonic transducer may be coupled into the object to be inspected via the ultrasonic coupling element. The ultrasonic coupling element may be formed of any suitable ultrasonic conductive material. For example, the ultrasonic coupling element may include a hard (rigid) ultrasonic material (e.g., Rexolite) that will allow the ultrasonic coupling element to provide a reference surface. Preferably, the ultrasonic coupling element includes a so-called dry or soft coupling material (e.g., thermosetting silicone rubber) that allows ultrasonic coupling with an object without the use of an ultrasonic coupling agent gel or the like. In other words, the ultrasonic coupling element may include an elastic (i.e., elastically deformable) ultrasonic coupling element.

[0022] The distal end of the elongated rod preferably comprises a reference surface for ultrasonic measurement. If a coupling element comprising a hard ultrasonic material is provided, the reference surface may be provided by a face of the coupling element. Alternatively, for example if the coupling element comprises a dry (soft) coupling material, a rigid surface of the elongated rod may provide the reference surface. For example, the distal end of an outer tubular sleeve may provide the reference surface. The transducer may also be appropriately aligned relative to the reference surface. For example, the transducer may be movably mounted within the elongated rod so that the transducer may translate back and forth along the longitudinal axis of the elongated rod.

[0023] The reference surface provides a physical reference or reference configured to contact the object to be measured. The reference surface is conveniently pre-aligned relative to the second reference surface of the second connector part. For example, the second reference surface can be aligned with the reference surface within 0.5°, more preferably within 0.25°, or more preferably within 0.1°. In this way, the reference surface can also be aligned relative to the first reference surface of the first reference part. For example, the connector assembly can ensure that (when the first connector part and the second connector part are connected) the reference surface is aligned to be parallel to the first reference surface within 0.5°, more preferably within 0.25°, or more preferably within 0.1°. The reference surface may include an annular surface or ring. If a movable joint is provided as described above, the reference surface may provide a reference surface that allows the elongated rod to be mechanically self-aligned with the surface of the object to be inspected. For example, the plane of the reference surface may be configured to be parallel to the plane of the surface with which it is placed in contact, thereby allowing ultrasound to be coupled into the object along a certain direction (e.g., along the surface normal of the object). The reference surface may comprise a single continuous reference surface (e.g., an annular ring or flat plate), or the reference surface may be formed by a plurality of (non-continuous) spaced apart surface segments (e.g., a plurality of partial ring segments). In a preferred embodiment, the elongated rod may comprise a tubular sleeve, and the distal end of the elongated (tubular) rod may provide the reference surface. For example, if the elongated member is tubular and has a circular cross-section, the distal annular end surface of the elongated tubular member may provide a planar reference surface.

[0024] The elongated rod can be mechanically locked to the base. In other words, the locking mechanism can be arranged to releasably lock the elongated rod to the base. The locking mechanism can prevent the elongated rod from rotating relative to the base when locked. The connector assembly can include a locking mechanism. In this way, the locking mechanism can releasably lock the first connector part and the second connector part together. Advantageously, the connector assembly includes an actuable locking mechanism to releasably lock the engagement of the first reference surface and the second reference surface. Therefore, when the locking mechanism has been actuated, the locking mechanism can ensure that the first reference surface and the second reference surface remain engaged or locked together. The locking mechanism can also be unlocked to allow the first reference surface and the second reference surface to disengage.

[0025] The locking mechanism can be implemented in various ways. In a preferred embodiment, the actuable locking mechanism includes an internally threaded collar for engaging at least one externally threaded portion of the first connector part and / or the second connector part. The collar can be rotatably attached to one of the first connector part and the second connector part, and the external thread is disposed on the other of the first connector part and the second connector part, and the external thread engages the internal thread of the collar. The rotation of the collar in a first direction can cause the first reference surface and the second reference surface to be tightly engaged by interaction with the (multiple) externally threaded portions. The engagement of the first reference surface and the second reference surface can then be released using rotation in the opposite direction, thereby unlocking the connector assembly. In this way, a robust physical connection that maintains a fixed relative position of the first reference surface and the second reference surface can be established. The rotation axis of the collar can be coaxial with the axis of the coaxial connector.

[0026] As described above, the connector assembly includes a coaxial electrical connector that provides an electrical connection between the ultrasonic transducer and the ultrasonic transducer driver while allowing the elongated rod to be fixed to the base in any rotational orientation around the longitudinal axis of the elongated rod. In other words, the elongated rod can be attached to the base in any rotational orientation. The coaxial electrical connector can be axisymmetric. Conveniently, the entire connector assembly is axisymmetric. Therefore, the connector assembly allows the elongated rod to be attached in different axial orientations. Then, the above-mentioned locking mechanism can lock the elongated rod in this orientation during use. This is advantageous because it allows the user to set the rotational orientation of the elongated rod before locking the elongated rod in place. This can allow, for example, the use of an elongated rod with a transducer and a coupling element angled away from the longitudinal axis of the elongated rod to measure a surface inclined relative to the base without having to adjust the orientation of the base. In other words, the elongated rod can be aligned to allow its coupling element to engage with the surface to be measured.

[0027] As explained above, the connector assembly also provides an electrical link between the ultrasonic transducer driver in the base and the ultrasonic transducer in the elongated rod. This electrical link is provided by a coaxial electrical connector. Advantageously, the connector assembly includes an electrical connector (i.e., a coaxial electrical connector) comprising a first part and a second part. Preferably, the first connector part comprises the first part of the electrical connector and the second connector part comprises the second part of the electrical connector. Therefore, the physical connection of the first connector part and the second connector part also serves to engage the first part and the second part of the electrical connector with each other to provide an electrical connection between the transducer driver and the transducer.

[0028] In a preferred embodiment, the first part of the electrical connector is laterally movable relative to the base. If the first connector portion of the base includes a first reference surface as described above, the first part of the electrical connector is preferably laterally movable relative to the first reference surface. The second part of the electrical connector may also or alternatively be laterally movable relative to the elongated rod. If the second connector portion includes a second reference surface as described above, the second part of the electrical connector is preferably laterally movable relative to the second reference surface. In this context, lateral (side-to-side) movement of these parts of the electrical connector means that these parts have a component of permitted movement in a direction orthogonal to the longitudinal axis of the elongated rod.

[0029] Allowing lateral movement means that the forces involved in establishing a physical connection between the first connector part and the second connector part can be isolated to some extent from the forces applied to the first part and the second part of the electrical connector. In other words, allowing lateral movement of the first part and the second part of the electrical connector allows these parts to cooperate to provide an electrical connection without the relative positions of these parts being constrained by the physical connection between the first connector part and the second connector part. This reduces wear and can also prevent damage to the first part and the second part of the electrical connector, thereby improving the reliability and life of the electrical link (i.e., even in the presence of vibration, good electrical contact can be maintained). Advantageously, the electrical connector also tolerates changes in the axial (longitudinal) position of the first part and the second part of the electrical connector. This again prevents damage to the electrical connector, allowing a good electrical link to be established and maintained, while also ensuring that the electrical connector does not interfere with the physical connection between the first connector part and the second connector part.

[0030] The first connector part and the second connector part can be configured to constrain the elongated rod angularly relative to the base (e.g., to ensure that the elongated rod protrudes from the base along a defined direction) without strictly constraining its relative lateral position. For example, if the first reference surface and the second reference surface are provided as part of the first connector part and the second connector part, these reference surfaces may include flat surfaces that define the relative angular alignment of the elongated rod relative to the base while allowing some lateral play in the physical connection. The electrical connector can then define the relative lateral position of the first connector part and the second connector part, and the first reference surface and the second reference surface define the angular alignment. The first connector part and the second connector part preferably firmly lock the relative position of the elongated rod and the base when connected. This prevents any further relative movement of the first part and the second part of the electrical connector after the elongated rod has been attached (e.g., locked) to the base.

[0031] The ultrasonic transducer may be operated as an ultrasonic transmitter. The ultrasonic transducer may be operated as an ultrasonic receiver. The ultrasonic transducer may be operated as both an ultrasonic transmitter and a receiver (i.e., the ultrasonic transducer may be an ultrasonic transceiver). The ultrasonic transducer driver may be arranged to send electrical signals to the ultrasonic transducer, which cause the transducer to transmit ultrasound. The ultrasonic transducer driver may be arranged to receive electrical signals from the ultrasonic transducer that have been generated by the ultrasonic transducer from the received ultrasound. The ultrasonic transducer driver may be arranged to both send electrical signals to the ultrasonic transducer and receive electrical signals from the ultrasonic transducer.

[0032] As described above, the electrical connector of the device includes a coaxial electrical connector. In other words, the coaxial electrical connector includes two or more concentric conductors separated by an electrical insulator. For example, the insulated center signal line can be surrounded by an outer concentric shield. This type of coaxial connector is advantageous in that it allows relatively high voltage and frequency transmission signals to be applied to the ultrasonic transducer without generating unwanted electromagnetic noise (e.g., to ensure compliance with EMC requirements) and transmitting low-intensity reception signals back to the ultrasonic transducer driver (i.e., with an acceptably high signal-to-noise ratio). The axis of the coaxial electrical connector can also coincide with the longitudinal axis of the elongated rod. The axis of the coaxial electrical connector can also coincide with the relative rotation axis of the first connector portion and the second connector portion.

[0033] The first and second parts of the coaxial electrical connector may be engaged by a push-fit action. When the first and second parts of the electrical connector are engaged, the first and second parts may not rotate significantly. For example, it may not be necessary to rotate the first and second parts relative to each other (e.g., the relative rotation of the first and second parts may be less than half a turn). Thus, an electrical connection is provided by push-fit (longitudinal or axial) movement of the first and second parts of the electrical connector. The push-fit action reduces physical wear and damage that may otherwise be caused by relative rotation of the first and second parts of the connector (e.g., a coaxial connector of the type described above) while engaging the first and second parts with each other.

[0034] In a preferred embodiment, engaging the first and second parts of the electrical connector using a push-fit action is followed by actuating a locking mechanism to mechanically lock the first and second connector parts together (e.g., engaging and locking the first and second reference surfaces in place). The mechanical lock may be provided by rotating a collar of the locking mechanism to secure or lock the first and second connector parts together, as described above. Allowing lateral movement of the first and second parts of the electrical connector reduces any lateral forces applied to the first and second parts of the electrical connector due to actuation of the locking mechanism, thereby reducing the risk of damage to the electrical connector and ensuring that the electrical connection is as noise-free as possible.

[0035] The ultrasonic measuring device is configured for use in an industrial environment. The ultrasonic measuring device can therefore be machine-mounted or machine-mountable, rather than handheld or manually carried. The ultrasonic measuring device can be mountable to a machine tool. For example, the ultrasonic measuring device can be attached to or attachable to a handle that can be held in the spindle of the machine tool. Therefore, the device can be used in a housing of a machine tool, in which a high-pressure coolant jet can exist, and chips are often ejected at high speed during cutting. Therefore, the connector assembly advantageously includes one or more seals to prevent fluid from entering when the first connector part and the second connector part are connected to each other. For example, the first and second parts of the connector assembly can include one or more O-ring seals to provide a fluid-tight seal. The fluid-tight seal can prevent fluid from reaching the coaxial electrical connector. The first connector part and the second connector part can also be arranged to prevent fluid from entering the rod and / or the base when they are not connected to each other.

[0036] Advantageously, the base includes one or more batteries. In other words, the base of the attached elongated rod and the transducer are powered by one or more internal batteries. The base also conveniently includes a wireless communication unit for wirelessly transmitting the measurement data derived from the ultrasonic transducer to the remote interface. The wireless communication unit can transmit and / or receive the measurement data via an optical link. The wireless communication unit can transmit and / or receive the measurement data via a radio link (e.g., a spread spectrum link, such as a frequency hopping spread spectrum link). The use of internal batteries and a wireless communication link eliminates the need for a trailing wire and allows the device to be stored in a tool change carousel adjacent to the machine tool housing and automatically change cutting tools, etc. when needed. An interface unit can also be provided for communicating with the wireless communication unit of the ultrasonic measurement device.

[0037] According to a second aspect of the present invention, there is provided a base for a measuring device of the first aspect of the present invention, the base comprising an ultrasonic transducer driver and a first connector portion, the first connector portion being configured to enable an elongated rod to be attached to the base and to provide an electrical connection to the ultrasonic transducer of the elongated rod, the first connector portion comprising a first part of a coaxial electrical connector.

[0038] According to a third aspect of the invention, there is provided an elongated rod for use in the measuring device of the first aspect of the invention. The elongated rod comprises an ultrasonic transducer and a second connector portion disposed at the proximal end of the elongated rod, the second connector portion being configured to enable the elongated rod to be attached to a base and to provide an electrical connection to the ultrasonic transducer driver of the base, the second connector portion comprising a second part of a coaxial electrical connector.

[0039] The present invention also extends to a rod extension member for use with an elongated rod as described above. The rod extension member can be located between the base and the elongated rod to extend the effective length of the elongated rod (e.g., to allow access to difficult-to-reach surfaces, such as deep holes or complex surfaces). The rod extension member can be an elongated body having a third connector portion disposed at its proximal end and a fourth connector portion disposed at its distal end. The third connector portion can be attachable to a first connector portion of the base, and the fourth connector portion can be attachable to a second connector portion of the elongated rod. An electrical connection can be provided by the rod extension member (i.e., to allow a transducer driver of the base to be electrically connected to a transducer of the elongated rod). The third connector portion and the fourth connector portion can be identical to the second connector portion and the first connector portion, respectively.

[0040] The invention also extends to an ultrasonic measurement kit for an industrial measurement device, the kit comprising a plurality of elongated rods according to the third aspect of the invention. Each elongated rod may have a different length and / or a different ultrasonic transducer configuration. The kit may also include a base. Thus, the kit allows different elongated rods to be attached to the base as required, thereby allowing a range of different measurement tasks to be performed using the ultrasonic measurement device. The invention also extends to a method comprising the step of attaching the elongated rod to the base.

[0041] Therefore, an ultrasonic measurement device is described herein. The ultrasonic measurement device may also be referred to as an ultrasonic measurement probe. The ultrasonic measurement device may be configured for use with an industrial measurement device. The industrial device may include a coordinate positioning machine, such as a CMM or a machine tool. The device may include a base (which may also be referred to as a base unit). The base may include an ultrasonic transducer driver (which may also be referred to as an ultrasonic transducer electronic circuit or an ultrasonic control module). The ultrasonic transducer driver may include a processor for controlling the ultrasonic transducer. The device may include an elongated rod. The elongated rod may also be referred to as a stylus. The elongated rod may include an ultrasonic transducer. The device may also include a connector assembly (or simply a connector). The connector assembly may be configured to releasably attach the elongated rod to the base. The connector assembly may include a first connector portion disposed on the base. The connector assembly may include a second connector portion disposed on the elongated rod. The second connector portion may be disposed at the proximal end of the elongated rod. The first connector portion and the second connector portion may provide mechanical alignment of the elongated rod relative to the base when connected. The first connector portion and the second connector portion may provide electrical connection between the ultrasonic transducer and the ultrasonic transducer driver when connected. Any one or more of these features and / or other features described in this application may be provided.

[0042] The present invention also describes an ultrasonic measuring device for an industrial measuring device, the ultrasonic measuring device comprising: a base, the base comprising an ultrasonic transducer driver; an elongated rod, the elongated rod comprising an ultrasonic transducer; and a connector assembly for releasably attaching the elongated rod to the base, the connector assembly comprising a first connector portion disposed on the base and a second connector portion disposed at the proximal end of the elongated rod, wherein the first connector portion and the second connector portion provide mechanical alignment of the elongated rod relative to the base and electrical connection between the ultrasonic transducer and the ultrasonic transducer driver when connected. The ultrasonic measuring device may include any of the features described herein, alone or in combination.

[0043] The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which;

[0044] Figure 1 shows a machine tool carrying an ultrasonic measuring device,

[0045] Figure 2a A view showing an ultrasonic measuring device,

[0046] Figure 2b and Figure 2c Shows from Figure 2a An end view of the ultrasonic measuring device as viewed from the planes marked GG and HH in FIG.

[0047] Figure 3 Shown in more detail Figure 2a to Figure 2c The base and the elongated rod of the ultrasonic measuring device when not attached,

[0048] Figure 4 Shown in more detail Figure 2a to Figure 2c The base and the elongated rod of the ultrasonic measuring device when attached, and

[0049] Figure 5a to Figure 5d The main steps when attaching the elongated rod to the base are shown.

[0050] refer to Figure 1 , a machine tool is shown. The machine tool comprises a housing 2 including a spindle 4 movable relative to a bed 3. The spindle 4 can be moved relative to the bed 3 under the control of a computer numerical controller (CNC) 6. In order to cut or process an object 8 placed on the machine bed 3, the spindle can carry a cutting tool (not shown). Instead of the cutting tool, a measuring sensor can also be mounted to the spindle 4 to allow the object 8 to be measured before or after the cutting process. Typically, such a measuring sensor and tool can be automatically loaded into the spindle 4 under the control of the CNC 6 to allow the desired cutting and measuring sequence to be implemented. In Figure 1 , an ultrasonic measuring device 10 is shown mounted to the spindle 4. The measurement information is transmitted wirelessly (e.g. via an optical or radio link) to an interface 12 which forwards such measurements to the machine tool controller 6. As will be explained below, the ultrasonic measuring device 10 allows internal characteristics of an object 8 to be measured, such as the thickness of the object.

[0051] Despite Figure 1 A machine tool is shown in FIG. 1 , but the ultrasonic measurement apparatus of the present invention may also be configured for use with other coordinate positioning devices, such as coordinate measuring machines (CMMs), industrial inspection robots, and the like.

[0052] refer to Figure 2a , Figure 2b and Figure 2c , shows an external view of the ultrasonic measuring device of the present invention. In particular, Figure 2a There is shown a base 20 and an elongated pole 22 of an ultrasonic measuring device 24 of the present invention. Figure 2b Shows from Figure 2a The plane GG shown is a view of the distal end of the base 20, and Figure 2c Shown (at different scales) from Figure 2a A view of the proximal end of the elongate rod 22 is shown looking at plane HH.

[0053] The base 20 has a sleeve 26 at its proximal end that allows the sleeve to be connected to a tool handle, which in turn can be held in the spindle of a machine tool. The distal end of the base 20 includes a first connector portion 28. The base 20 also includes a radio frequency (RF) transparent portion that allows RF signals to enter and exit a spread spectrum (e.g., frequency hopping) RF communication module 25 located within the base 20. A transducer driver 29 is also located within the base 20, along with a set of batteries 27, which can be accessed via a battery cover 30.

[0054] The elongated rod 22 includes a protruding coupling element 32 at its distal end that acoustically couples to a transducer 33 located within the elongated rod 22. A reference surface 34 is also provided at the distal end of the elongated rod, adjacent the coupling element 32. A second connector portion 36 is provided at the proximal end of the elongated rod 22, the second connector portion including a rotatable collar 38.

[0055] Figure 2b There is shown an end view of the distal end of the base 20. It can be seen that the housing 40 of the base has a circular cross-section arranged concentrically with the first connector part 28. The first connector part 28 includes an externally threaded shroud member 42 and a female coaxial electrical connector socket 44.

[0056] Figure 2c An end view of the proximal end of the elongate rod 22 is shown including the second connector portion 36. A male coaxial electrical connector plug 46 is shown along with a member 48 forming part of the elongate rod 22 and an internally threaded collar 38 rotatable relative to the remainder of the elongate rod 22.

[0057] refer to Figure 3 and Figure 4 , a longitudinal section through the base 20 and the elongated rod 22 is shown. Figure 3 and Figure 4 The base 20 and elongate rod 22 are shown unattached and attached, respectively, with the inset providing an enlarged view of the connector assembly; the connector assembly being a combination of the first connector portion 28 and the second connector portion 36 .

[0058] The female coaxial electrical connector receptacle 44 of the first connector portion 28 and the male coaxial electrical connector plug 46 of the second connector portion 36 are shown as being located on a central (longitudinal) axis 50. The externally threaded shroud of the first connector portion 36 includes a threaded region 52 and is generally coaxial with the female coaxial electrical connector receptacle 44. The collar 38 of the second connector portion 36 is rotatably connected to the remainder of the elongated rod 22 and is sized so that threads formed on the inside of the collar 38 can engage with the threaded region 52 of the externally threaded shroud of the first connector portion 28. The first connector portion 28 also includes a first reference surface 54, and the second connector portion 36 includes a second reference surface 56.

[0059] exist Figure 4 In the "attached" configuration shown, the female coaxial electrical connector receptacle 44 engages the male coaxial electrical connector plug 46, thereby providing an electrical connection. The first reference surface 54 and the second reference surface 56 also physically engage, thereby defining the mechanical orientation of the elongated rod 22 relative to the base 20. The female coaxial electrical connector receptacle 44 and the male coaxial electrical connector plug 46 are free to move laterally a small amount relative to the remainder of the respective first and second connector parts. This prevents the relative position of the two parts of the electrical connector from being constrained by the physical alignment provided by the first reference surface 54 and the second reference surface 56.

[0060] Next reference Figure 5a to Figure 5d , showing the process of making a physical and electrical connection between a first connector part and a second connector part.

[0061] Figure 5a The first connector portion 28 and the second connector portion 36 are shown aligned with each other prior to forming a physical and electrical connection between the elongated rod 22 and the base 20 .

[0062] Figure 5b The first stage in the attachment process is shown. The user inserts the male coaxial electrical connector plug 46 of the second connector part 36 into the female coaxial electrical connector receptacle 44 of the first connector part 28 .

[0063] Figure 5c It is shown how further longitudinal movement is provided until the first reference surface 54 of the first connector part 28 and the second reference surface 56 of the second connector part 36 engage. At this stage, the frictional engagement of the male coaxial electrical connector plug 46 with the female coaxial electrical connector socket 44 means that the elongated rod 22 is loosely held in place.

[0064] Figure 5d It is shown that after the collar 38 has been rotated, the elongated rod 22 is securely locked to the base 20. In particular, the collar rotation causes the first reference surface 54 and the second reference surface 56 to fully engage and then remain in tight engagement. Importantly, the freedom of the male coaxial electrical connector plug 46 and the female coaxial electrical connector receptacle 44 to move laterally means that the electrical connection is established without applying any strain to the coaxial connector, thereby preventing degradation of the electrical connection.

[0065] Removal of the elongate rod 22 from the base 20 is achieved by reversing the above-described stages.

[0066] The skilled person will appreciate various alternatives and variations to the above arrangement. For example, the shape and relative dimensions of the base and the elongated rod may be changed, and further electrical or mechanical connections may be provided.

Claims

1. An ultrasonic measuring device for an industrial measuring device, the ultrasonic measuring device comprising: a base, the base comprising an ultrasonic transducer driver, an elongated rod including an ultrasonic transducer, and a connector assembly for releasably attaching the elongated rod to the base, the connector assembly comprising a first connector portion disposed on the base and a second connector portion disposed at a proximal end of the elongated rod, the first connector portion and the second connector portion providing mechanical alignment of the elongated rod relative to the base and electrical connection between the ultrasonic transducer and the ultrasonic transducer driver when connected, It is characterized in that The connector assembly includes a coaxial electrical connector that enables the electrical connection to be established between the ultrasonic transducer and the ultrasonic transducer driver, and the elongated rod is fixedly connected to the base in any rotational orientation about the longitudinal axis of the elongated rod.

2. The ultrasonic measuring device according to claim 1, wherein: The first connector portion includes a first reference surface and the second connector portion includes a second reference surface, and when the first connector portion and the second connector portion are connected, the engagement of the first reference surface and the second reference surface provides orientation alignment of the elongated rod relative to the base.

3. The ultrasonic measuring device according to claim 2, wherein: The distal end of the elongated rod includes a reference surface for ultrasonic measurement, which is pre-aligned relative to a second reference surface of the second connector part.

4. The ultrasonic measuring device according to any one of claims 2 to 3, wherein: The connector assembly includes an actuatable locking mechanism for releasably locking the first reference surface and the second reference surface in engagement.

5. The ultrasonic measuring device according to claim 4, wherein: The actuatable locking mechanism comprises an internally threaded collar for engaging at least one externally threaded portion of the first and / or second connector part.

6. Ultrasonic measurement apparatus according to any preceding claim, wherein: The connector assembly is axisymmetric.

7. Ultrasonic measurement apparatus according to any preceding claim, wherein: The coaxial electrical connector assembly includes a coaxial electrical connector including a first part and a second part, the first connector portion including the first part of the coaxial electrical connector, and the second connector portion including the second part of the coaxial electrical connector.

8. The ultrasonic measuring device according to claim 7, wherein: The first part of the coaxial electrical connector is capable of moving laterally relative to the base, and / or the second part of the coaxial electrical connector is capable of moving laterally relative to the elongated rod.

9. The ultrasonic measuring device according to any one of claims 7 to 8, wherein: The first part and the second part of the coaxial electrical connector are engaged by a push-fit action.

10. Ultrasonic measurement apparatus according to any preceding claim, wherein The connector assembly includes one or more seals to prevent ingress of fluid when the first connector portion and the second connector portion are connected to each other.

11. Ultrasonic measurement apparatus according to any preceding claim, wherein: The base includes one or more batteries and a wireless communication unit for wirelessly transmitting measurement data derived from the ultrasound transducer to a remote interface.

12. A base for a measuring device according to any preceding claim, the base comprising an ultrasonic transducer driver and a first connector part, the first connector part being configured to enable an elongated rod to be attached to the base and to provide an electrical connection to the ultrasonic transducer of the elongated rod, the first connector part comprising a first part of a coaxial electrical connector.

13. An elongated rod for a measuring device according to any one of claims 1 to 11, the elongated rod comprising an ultrasonic transducer and a second connector portion arranged at the proximal end of the elongated rod, the second connector portion being configured to enable the elongated rod to be attached to a base and to provide an electrical connection to the ultrasonic transducer driver of the base, the second connector portion comprising a second part of a coaxial electrical connector.

14. A rod extension member for an elongated rod according to claim 13, wherein the rod extension member comprises an elongated body having a third connector portion arranged at the proximal end of the elongated body and a fourth connector portion arranged at the distal end of the elongated body, wherein the third connector portion is capable of being attached to the first connector portion of the base, and the fourth connector portion is capable of being attached to the second connector portion of the elongated rod.

15. An ultrasonic measurement kit for an industrial measurement device, the kit comprising a plurality of elongated rods according to claim 13, each of the elongated rods having a different length and / or a different ultrasonic transducer configuration.

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