Patent Publication Number: US-2019176287-A1

Title: Live tool having monoblock with fluid channel and fluid driven spindle

Description:
RELATED APPLICATIONS 
     This is a Continuation of U.S. patent application Ser. No. 15/410,218 filed Jan. 19 2017, now U.S. Pat. No. 10,207,379, which claims priority to U.S. Provisional Application No. 62/281,431, filed Jan. 21, 2016. The contents of the aforementioned applications are incorporated by reference in their entirety. 
    
    
     FIELD OF INVENTION 
     This disclosure relates to live tools, such as mechanical and fluid drive spindles. This disclosure also relates to enclosed machining centers in which the live tools are used. 
     BACKGROUND 
     Machining centers are often used for metal and wood cutting or milling processes to shape a workpiece into the desired configuration. The process of forming a finished product can require several distinct types of cutting or milling requiring a variety of different tool and a variety of relative motions between the workpiece and the tool. To provide for the substantially continuous processing of the workpiece, machining centers often include automatic tool changers (ATC) that are capable of changing out the in-use tools. 
     Often, some of the tools within the ATC are live tools. Live tools provide a rotating cutting tool in additional to the translational motion of the tools themselves. Live tools may be mechanically driven live tools or may be fluid driven live tools. In the case of mechanically drive live tools, the machining center may operate a centralized motor that is mechanically engaged with the live tool when the live tool has been selected for use. Thus, knowledge of the operating conditions of the live tool must be inferred from the operation of the centralized motor within the ATC. 
     In the case of fluid driven spindles, the centralized drive motor may not be required at all. Within relying upon the wired communication between a controller of the machining center and the ATC, there may not be any way to fully monitor the operation of a fluid driven spindle in-use within a machining center set up for mechanical live tools. In other words, current machine control systems may be unable to sufficiently determine the live tool&#39;s operating condition for access control or other reasons. Even when powered through the machine control system, the tool&#39;s operating condition is monitored indirectly from afar, such as through a centralized motor. This indirect monitoring can lead to inaccuracies caused by time lag or a break in the system. Therefore there is a need for a system that allows for local, accurate monitoring of the operation of live tools. Preferably, there is a need for a monitoring system that may be applied somewhat universally to existing live tools. 
     SUMMARY 
     The present disclosure seeks to improve communication between machining centers and the live tools in-use therein. In some embodiments, the present disclosure provides a system that may be substantially universally applied to existing live tools. 
     The present disclosure may be cast in the form of the following paragraphs: 
     Paragraph 1. A live tool system, the system comprising: 
     a live tool; 
     a collar surrounding a rotating shaft or a rotating cutting tool of the live tool, the collar housing at least one sensor capable of monitoring an operating condition proximate to the cutting tool during a cutting operation; and 
     a wireless transmitter in communication with the at least one sensor for transmitting a signal for use by a machining center controller. 
     Paragraph 2. The live tool system of Paragraph 1, wherein the at least one sensor is a temperature sensor and the operating condition comprises the temperature adjacent to the cutting tool. 
     Paragraph 3. The live tool system of Paragraph 2, further comprising: a wireless receiver capable of receiving signals sent from the wireless transmitter; and 
     a controller connector for operably connecting the wireless receiver to the machining center controller, 
     wherein the controller connector is configured to relay temperature information to the machine center controller for adjusting at least one function of the machining center in response to the temperature information. 
     Paragraph 4. The live tool system of Paragraph  1 , wherein the at least one sensor is a vibration sensor and the operating condition comprises vibration caused by the rotation and cutting operation of the cutting tool. 
     Paragraph 5. The live tool system of Paragraph 1, wherein the collar is configured to replace a collet or a collet locking nut used to secure the cutting tool to the live tool. 
     Paragraph 6. The live tool system of Paragraph 5, wherein the collar is an ER Collet Chuck Lock Nut. 
     Paragraph 7. The live tool system of Paragraph 1, wherein the collar is held in place by a collet locking nut. 
     Paragraph 8. The live tool system of Paragraph 1, wherein the collar is mounted to the live tool with a bracket band. 
     Paragraph 9. The live tool system of Paragraph 1, further comprising a housing for the wireless transmitter, the housing being mounted to the live tool at a location remote from the collar, and the wireless transmitter is connected to the collar by a cable. 
     Paragraph 10. The live tool system of Paragraph 1, wherein the housing is mounted to the live tool by a transmitter connector band. 
     Paragraph  11 . The live tool system of Paragraph  1 , wherein the live tool is a fluid drive live tool. 
     Paragraph 12. The live tool system of Paragraph 1, wherein the live tool is a mechanically driven live tool. 
     Paragraph 13. The live tool system of Paragraph 1, wherein the at least one sensor functions without modification to the shaft or the cutting tool. 
     Paragraph 14. A wireless monitoring kit for mounting to a live tool, comprising: a collar configured to mount to the live tool such that the collar at least partially surrounds a rotating shaft or a rotating cutting tool of the live tool, the collar housing at least one sensor capable of monitoring an operating condition proximate to the cutting tool during a cutting operation; and 
     a wireless transmitter in communication with the at least one sensor for transmitting a signal for use by a machining center controller. 
     Paragraph 15. The kit of Paragraph 14, wherein the at least one sensor is a temperature sensor and the operating condition comprises the temperature adjacent to the cutting tool. 
     Paragraph 16. The kit of Paragraph 15, further comprising: 
     a wireless receiver capable of receiving signals sent from the wireless transmitter; and 
     a controller connector for operably connecting the wireless receiver to the machining center controller, 
     wherein the controller connector is configured to relay temperature information to the machine center controller for adjusting at least one function of the machining center in response to the temperature information. 
     Paragraph 17. The kit of Paragraph 14, wherein the at least one sensor is a vibration sensor and the operating condition comprises vibration caused by the rotation and cutting operation of the cutting tool. 
     Paragraph 18. The kit of Paragraph 14, wherein the collar is configured to replace a collet or a collet locking nut used to secure the cutting tool to the live tool. 
     Paragraph 19. A method of monitoring a live tool, comprising: 
     mounting a collar around at least one of a cutting tool, a collet, and a shaft of the live tool, the collar comprising at least one temperature sensor; 
     mounting a wireless transmitting unit to the live tool, the wireless transmitting unit in communication with the at least one temperature sensor; and 
     sensing the temperature adjacent to the cutting tool during a cutting operation using the at least one sensor. 
     Paragraph 20. The method of Paragraph 19, further comprising: 
     transmitting a signal representative of the sensed temperature to a wireless receiver in communication with a controller of a machining center; and 
     adjusting or terminating operation of the live tool when a spike in temperature is detected. 
    
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         FIGS. 1A and 1B  show an example of a fluid driven cutting tool spindle usable with machining centers disclosed. 
         FIG. 2A  shows a second example of a fluid driven cutting tool spindle usable with machining centers disclosed. 
         FIG. 2B  shows a detailed view of  FIG. 2A  according to one embodiment thereof. 
         FIG. 2C  shows a detailed view of  FIG. 2A  according to a second embodiment thereof. 
         FIG. 3  shows a machining center according to some embodiments of the present disclosure. 
         FIG. 4  shows a machining center according to some other embodiments of the present disclosure. 
         FIG. 5  shows a schematic representation of a sensor module according to embodiments of the present disclosure. 
         FIG. 6  shows a flow chart of an embodiment of the operation of the machining center of the present disclosure. 
         FIG. 7  shows a flow chart according to some door monitoring embodiments of the machining center of the present disclosure. 
         FIG. 8  shows a flow chart according to some spindle monitoring embodiments of the machining center of the present disclosure. 
         FIG. 9  shows another example of a live tool usable with machining centers disclosed. 
         FIG. 10A  shows yet another example of a live tool usable with machining centers disclosed. 
         FIG. 10B  shows an exploded view of the live tool of  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of this disclosure are described below and illustrated in the accompanying figures, in which like numerals refer to like parts throughout the several views. The embodiments described provide examples and should not be interpreted as limiting the scope of the invention. Other embodiments, and modifications and improvements of the described embodiments, will occur to those skilled in the art and all such other embodiments, modifications and improvements are within the scope of the present invention. Features from one embodiment or aspect may be combined with features from any other embodiment or aspect in any appropriate combination. For example, any individual or collective features of method aspects or embodiments may be applied to apparatus, product or component aspects or embodiments and vice versa. 
     In some cases, fluid driven cutting tool spindles are replacing the use of electric spindles. The fluid driven cutting tool spindles may be capable of providing higher rotational speeds and are sometimes referred to as high-speed spindles. 
       FIGS. 1A and 1B  show an example of a fluid driven cutting tool spindle  200  that may be compatible with machining centers described in this disclosure. The fluid drive cutting tool spindle  200  is an embodiment designed for use with a wireless monitoring system as discussed below. The fluid driven cutting tool spindle  200  of this disclosure may be driven by liquid or gas passing through the spindle&#39;s housing at relatively high pressures. The fluid driven cutting tool spindle  200  of  FIGS. 1A and 1B  is similar to high speed spindles described in related, jointly owned, U.S. patent app. Ser. No. 14/461,006 filed on Aug. 15, 2014, which is incorporated herein in its entirety. 
     As seen in  FIG. 1A , the fluid driven cutting tool spindle  200  includes a shank  210 , a housing  220  and a sensor module  230  mounted to the housing  220 . As seen in  FIG. 1B , the shank  210  and the housing  220  define a fluid channel  240 . Fluid exiting the fluid channel  240  may act upon a shaft  250  to rotate the shaft  250  around a rotation axis A shown in  FIG. 1A . A cutting insert  130  (see  FIG. 4 ) may be mounted to the end of the shaft  250  for synchronous rotation therewith. 
     The housing  220  may have an opening  225  to provide a generally unobstructed path between the sensor module  230  and the shaft  250 . In some embodiments, the opening  225  may be physically obstructed but substantially transparent to specific frequencies of the electromagnetic spectrum. 
       FIG. 2A  shows an alternative fluid driven cutting tool spindle  200 ′. The fluid driven cutting tool spindle  200 ′ may be mounted in a monoblock  270  of a tool turret. The monoblock  270  provides the fluid and passages for powering the shaft  250 ′ instead of requiring a specific spindle housing. As shown in  FIG. 2B  the monoblock  270  may also have an opening  225 ′ and an associated sensor module  230 ′. In other embodiments, as shown in  FIG. 2C , the sensor module  230 ′ indirectly assesses spindle characteristics by monitoring fluid characteristics passing through the monoblock without an opening into the shaft. 
     The present disclosure should not be limited to the fluid driven spindles  200 ,  200 ′ disclosed above. Other configurations of fluid driven spindles  200  may also be suitable for the present disclosure. For example, the driving fluid may be channeled through the shaft of the spindle instead of the housing or the monoblock. As discussed above, mechanical spindles may also benefit from one or more aspects of the present disclosure. 
       FIG. 3  shows a machining center  100 . Machining centers within the scope of this disclosure include milling or turning centers, automatic, CNC, semi-automatic or manual stations. In this non-limiting example, the fluid driven cutting tool spindle  200  is mounted within a machine spindle  110  that is disposed within the machining center  100 . The fluid driven cutting tool spindle  200  supports a cutting insert  130  (as referred to as a cutting tool). The machine spindle  110 , fluid driven cutting tool spindle  200 , cutting insert  130 , and a workpiece  140  are housed within an enclosure  102  of the machining center  100 . The workpiece  140  may sit upon or be held by a workpiece support  145  that may be movable. The enclosure  102  may be accessed through at least one door  160 . The at least one door  160  includes a selectively engaged latch  150  that is capable of locking the door  160  in a closed position. 
     As used herein, the term door refers to any means by which at least the primary opening of the machining center is closed. The primary opening of the machining center is the opening through which the workpiece is inserted and removed from the machining center. The door may be hinged, folding, sliding or any other means known in the art. The door may include a single pane or multiple panes. The door may be operated manually or automatically. The door may have at least one handle or other manipulation means known in the art. 
     In a conventional system, a machine control system operates the machine spindle  110  and the latch  150  in a wired configuration. When operating, the machine spindle is electrically powered to rotate, therefore turning the cutting insert  130 . The machine control system controls the current to the machine spindle  110  that causes rotation, and when current is no longer being supplied to the machine spindle, the machine control system can disengage the latch  150 . This wired communication between the machine spindle  110  and the machine control system may utilize an encoder to provide a signal that triggers engagement and disengagement of the latch  150 . 
     However, the housing of the fluid driven cutting tool spindle  200  is intended to remain substantially rotationally stationary as fluid is run through the fluid driven cutting tool spindle  200  to rotate the cutting insert  130  with the driven shaft. Under this configuration, a conventional machine control system can be deprived of its ability to determine the active operation of the machine spindle  110  that would otherwise trigger the unlocking of the latch  150 . 
     To help cure this potential problem, inventors have provided a sensor module  230  (see  FIG. 5 ) mounted to, mounted on, embedded within, or operably arranged relative to the fluid driven cutting tool spindle  200  or the support structure, such as monoblock  270 , thereof. The sensor module  230  monitors one or more operating conditions of the fluid driven cutting tool spindle  200 . Operating conditions can include, but are not limited to, rotational speed of the shaft  250 , rotational speed of the cutting insert  130 , characteristics of fluid flow, such as pressure or flow rate, translational speed or acceleration of the housing  220 , or relative position, speed or acceleration of the fluid driven cutting tool spindle  200  relative to the workpiece  140  or the workpiece support  145 . Changes in operating conditions of the fluid driven cutting tool spindle  200  should lead to adjustment in one or more functions of the machining center. Functions of the machining center include, but are not limited to, allowing and baring access to the enclosure, driving the shaft  250  of the fluid driven spindle  200 , and processing a workpiece by contacting the cutting insert  130  with a workpiece and providing relative translational motion therebetween. Some but not all of these functions may be controlled, managed or adjusted via the machining center controller  190 . In some embodiments, the machining center controller  190  is an internal controller, or includes multiple components located on or within the machining center  100 . Those functions controlled by the machining center controller may be referred to as processing conditions. Therefore processing conditions relate at least to the conditions under which a workpiece is processed, such as the relative motion of the workpiece relative to the cutting insert  130 , or the fluid characteristics used to drive the shaft  250 . 
     In some embodiments, the sensor module  230  may directly monitor the rotational speed of the shaft  250  through the opening  225 . For example, the sensor module  230  may include non-contact motion sensors such as an optical sensor  232  capable of sensing rotational speed by monitoring of a visual mark located on the shaft  250 , where the mark periodically sweeps through the vision of the optical sensor  232 . The optical sensor  232  may use any known optical technology, such as visible light, laser, infra-red light, or ultraviolet light. 
     Alternatively or additionally, the sensor module  230  may include sensors based on electromechanical, magnetic, optical, magnetoelastic, or field-effect technologies, such as an electromagnetic sensor  234  capable of sensing rotational speed by monitoring the frequency resulting from a magnetic marker placed upon the shaft  250  as the magnetic marker rotates past the electromagnetic sensor  234 . In some embodiments, non-contact motion sensors within the sensor module  230  may use microwave technology. 
     Alternatively or additionally, the sensor module  230  may include a pressure sensor  236  (see  FIG. 5 ) in fluid communication with the fluid channel  240  (see  FIG. 1B ) or other path of driving fluid. The pressure sensor  236  may monitor the magnitude of the fluid pressure running through the fluid channel  240 . A fluid sensor that reads low, or zero, relative fluid pressure may infer a low or zero rotational speed for the shaft  250 . Thus the sensor module  230  with a pressure sensor  236  would indirectly determine the approximate rotational speed of the shaft  250  and the cutting insert  130 . In other embodiments other fluid sensors may be used that operate based on related characteristics such as flow rate. As understood from the preceding, in some embodiments, more than one type of sensor may be used to monitor separate operating conditions of the fluid driven cutting tool spindle  200 . 
     In some embodiments, the fluid driven cutting tool spindle  200  is at rest when the shaft speed, as sensed by the sensor module  230 , is approximately zero RPM. In some embodiments, the sensor module  230  includes a wireless transmitter  260  (see  FIG. 5 ). The wireless transmitter  260  may transmit a signal, indicative of sensor information received from a sensor, when the shaft  250  is at rest, i.e. zero RPM, or below some other predetermined, relatively slow, RPM. In other embodiments, the wireless transmitter  260  may substantially continuously, repeatedly or periodically transmit a signal that may directly or indirectly communicate the rotational speed of the shaft  250 , or other information concerning other operating conditions of the fluid driven cutting tool spindle  200 . 
     The sensor module  230  may use the wireless transmitter  260  to communicate wirelessly with a wireless receiver  170 . The sensor module  230  may include a power source  262 , such as a battery, or provide power to the sensors  232 ,  234 ,  236  and the wireless transmitter  260  of the sensor module  230  through an optional processor  264 . The optional processor  264  may allow the necessary calculations concerning operating conditions to be computed by the sensor module  230 . In other embodiments, the sensor module  230  transmits the rare data (e.g. a frequency) for interpretation by the machining center controller  190  or a processor associated with the wireless receiver  170 . The wireless transmitter  260  may include a RF transmission unit  266  and an antenna  268 . 
     In some embodiments, the wireless receiver  170  is connected to a fixture  180  that may be mounted within the enclosure  102  of the machining center  100 . In some embodiments there is a direct line of sight between the sensor module  230  and wireless receiver  170 . In other embodiments, wireless receiver  170  accepts signals transmitted from the sensor module  230  that are reflected from a surface within the enclosure  102  of the machining center  100 . 
     The wireless receiver  170  is operably connected to the machining center controller  190  by a controller connector (discussed below) such that signals received by the wireless receiver  170  can be used by the machining center controller  190 . In other words, the controller connector may relay information from the wireless receiver to the machining center controller. In some embodiments, once the machining center controller  190  processes the signal, it can communicate with the at least one latch  150 , which secures the at least one door  160 , in a conventional fashion to allow for accessing the enclosure  102 . In other embodiments, the signal does not have to be processed by the machining center controller  190  because the signal is provided in a format already recognized by the machining center controller  190 . 
       FIG. 4  shows an alternative embodiment for selectively allowing access to the machining center&#39;s enclosure  102 . In the embodiment of  FIG. 4 , the wireless transmitter  260  of the sensor module  230  communicates wirelessly with the wireless receiver  170  that is in operational communication with the at least one latch  150  without relying upon the machining center controller  190 . In some embodiments, the wireless receiver  170  is connected to the fixture  180  mounted on the door  160 . In other embodiments, the fixture  180  may be mounted or incorporated with the latch  150 . In still other embodiments, the wireless receiver  170  may itself be mounted to or integrated within the latch  150 . 
     The operating principles of the machining center  100  may necessitate that the door latch  150  should be engaged, i.e. the latch provided in a locked position and unable to be opened, at all times that the machining center  100  is powered on, unless the sensor module  230  indicates that the operating condition of the shaft  250  meets a related access criteria. In one embodiment, where the operating condition is the rotational speed of the shaft  250 , the access criteria could be that the shaft  250  is at rest, or rotating at an otherwise acceptably low speed below a minimum threshold. 
     In some embodiments, the sensor module  230  may monitor motions of multiple axes instead of, or in addition to, rotation of the shaft  250 . For example, the sensor module  230  may include an accelerometer  238 . In instances where the machine spindle  110  is capable of movement along the rotation axis A, or movement of the rotation axis A in space, the accelerometer  238  could sense these motions and transmit appropriate signals to prevent access into the enclosure  102  while parts are in motion. 
     In some embodiments additional motion sensors may be provided within the sensor module  230 , or separate therefrom in order to monitor motion of other potentially movable elements within the enclosure. Examples of other movable elements that may be within the enclosure include: moving components of the workpiece support  145 , moving components of measurement systems, moving components of auxiliary systems such as material handling systems, moving components of material removal systems such as metal shavings, cutting fluids etc. In each of the above examples, the same principle applies: the door latch  150  remains engaged to lock the door  160  at all times that the machine power is on, unless the plurality of motion sensors and sensor modules indicate that the access criteria for all of the axes is met, at which time, the door latch  150  can be disengaged and the door  160  can be opened. 
     In some embodiments, the access criteria may be set to allow access to the enclosure  102  if internal elements are moving with some speed below a minimum threshold, such as a minimum 10, 30 or 100 RPM of the shaft  250  or a minimum speed of 200, 500 or 1000 mm/min along any axis of motion for any moving component. 
     In some embodiments, the machining center  100  may include more than one door  160 . One or more latches  150  may operate to lock the free ends of each door  160  with respect to one another. In other words each latch  150  may simultaneously lock the two doors  160  shown in  FIGS. 3 and 4 . The latches  150  may include a mechanical or an electro mechanical element that, when applied, can lock the machining center door and may also include an actuator that can change the element state such that the machining center door can be opened. 
     According to some embodiments related to  FIG. 3 , the communication between the wireless transmitter  260  and the wireless receiver  170  of the machining center controller  190  may allow for control of parameters beyond the locking and unlocking of the latch  150 . For example, the wireless transmitter  260  may provide signals sufficient for the machining center controller  190  to substantially continuously monitor rotational speed of the shaft  250 , and changes in rotational speed thereof, due to the material removal process. The shaft  250  is understood to be rotating at the same speed as a cutting insert  130  held therein. Therefore monitoring the shaft  250  can provide information about the operation of the cutting insert  130 . Additionally, the cutting insert  130  could be monitored to provide information about the operation of the shaft  250 . The rotational speed can be affected by numerous variables, such as cutting depth, tool sharpness, material hardness, tool breakage, and others. 
     While the machining center controller  190  indirectly drives the shaft  250  to rotate via the fluid pressure, the machining center controller  190  may control relative translational movement of the cutting insert  130  by moving the machine spindle  110  or the workpiece  140  via the workpiece support  145 . It therefore may be beneficial to link the rate of translational motion imparted electrically by the machine center controller as a function of the shaft rotational speed. For example, if the rotation speed is decreasing due to a change in trajectory, the machining center controller  190  may slow down the relative translational motion to maintain a near constant rotation speed of the shaft  250  and cutting insert  130 . Reducing relative translational motion should reduce the stresses between the workpiece  140  and the cutting insert  130  allowing for an increase in rotational speed. In effect, the sensor module  230  in connection with the wireless transmitter  260  and wireless receiver  170  provides a feedback loop to the machining center controller  190  that may otherwise not exist when operating fluid driven cutting tool spindles  200  without the sensor module  230 . 
     According to some embodiments, the machining center controller  190  may be configured to operate a valve or other means capable of adjusting the pressure or flow rate of driving fluid for the fluid driven cutting tool spindle  200 . Therefore the machining center controller  190  may be able to increase the pressure within the fluid channel  240  in an attempt to increase shaft rotation speed if the sensor module  230  senses an unexpected reduction is rotational speed. In other embodiments, the machining center controller  190  may be configured to shut off fluid to the fluid driven cutting tool spindle  200  if the shaft&#39;s rotational speed experiences a significant unexpected spike. Such a spike in the rotational speed of the shaft  250  may be an indication that the cutting insert  130  has broken and the machining center  100  should be shut off and maintenance performed. 
     Several different approaches have been considered by the inventors for implementing the improved machining centers disclosed herein. In one embodiment, a conventional machining center and conventional fluid driven cutting tool spindle may be retrofit to allow the disclosed communication and functions between the spindle and the machining center. The retrofit may be provided by a kit. The kit may include the sensor module  230 , a wireless receiver  170 , and components for operatively connecting the wireless receiver to the machine center controller  190  such that the machine center controller receives a signal having information that is understandable by the machine center controller for determining accessibility of the enclosure. The signal may provide understandable information in a form similar to data traditionally provided to a machine control system from an encoder. The components for operatively connecting may include hardware to operably connect the wireless receiver to the machining center controller. The components for operatively connecting may also include hardware or software if necessary to convert data from the sensors into the appropriate format for use by the machining center controller. 
     The optional hardware or software for translating the senor data into a usable signal for the machine center controller may be contained within or accessed by the machine center controller. For example, software may be provided on a computer readable medium for installation onto said memory. Alternatively, the software may be stored on a computer readable medium that is not provided with the kit. Instead, the software may be downloaded by the machining center controller by accessing an internet address, requesting the software for download, providing an access key or verification, and receiving into memory of the machining center controller the software requested. 
     In other embodiments, the optional hardware or software may be pre-installed within the sensor module  230 . In other embodiments, the optional hardware or software may be incorporated into a module with the wireless receiver  170 . 
     The components for operatively connecting the wireless receiver to the machine center controller  190  may take any number of forms known in the art. For example, a wired connection may be made with a pre-exiting port provided on the machine center controller. Alternatively, a port may be included in the kit for joining to the machine center controller&#39;s mother board or other bus. In still other embodiments, the wireless receiver can be wired to or even mounted to machine center controller&#39;s mother board or Bus. Each of these embodiments may be collectively described as a controller connector. 
     Some fluid driven spindles are available with wireless sensor modules already included. These modules communicate with an independent display traditionally unable to function in association with the machine center controller as set out in this disclosure. Therefore an example retrofit kit for a conventional machining center in use with a fluid driven spindle that previously includes a sensor and output display may comprise only the components for operatively connecting the display/receiver to the machine center controller. 
     In some other embodiments a conventional machining center with electric spindles may be retrofit with a kit having the fluid driven cutting tool spindle  200  and the sensor module  230 , a wireless receiver  170 , components for operatively connecting the wireless receiver to the machine center controller  190 . 
     In other embodiments, the operator may be provided with a machining center built specifically to perform the functions discussed in this disclosure. In this embodiment, the wireless receiver  170  may be integrated with the machine center controller  190 . 
     Other ways to implement controlling machining center parameters, such as the locking and unlocking of a door latch, or adjustment of fluid pressure, using wireless signals from a sensor, which monitors fluid driven cutting tool spindle operating conditions may also be possible. These other examples include, but are not limited to, using a control system that bypasses the machining center controller of a conventional machining center completely. 
       FIG. 6  provides a general flow chart illustrating the operation of machining centers according to embodiments of the present disclosure. A sensor module  230  monitors the shaft of a fluid driven cutting tool spindle  200  at step  601 . Wireless transmission occurs between the sensor module  230  and a wireless receiver  170  at step  602 . The machining center controller  190  then receives a signal from the wireless receiver  170  either directly or indirectly by wired or wireless transmission at step  603 . 
       FIG. 7  shows an example decision tree using the disclosed machining center to control access thereto. The process starts at step  700 . The locked or unlocked condition of the latch  150  may be initially checked at step  702 . If the latch  150  is unlocked, an alert may be sent to the operator at step  704 . If the latch  150  is locked, the machining center controller  190  will enable spindle operation through the provision of driving fluid and current to the necessary electrical components at step  706 . The operating conditions of the fluid driven cutting tool spindle  200  may then be monitored to determine whether the RPM of the spindle meets a predetermined access criteria, such as whether the RPM is above a predetermined threshold (step  708 ). If the RPM fails to meet the access criteria, the system returns to confirm that the latch  150  remains locked. If the RPM is determined to meet the access criteria, the machining center controller can be signaled to unlock the latch or enable the user to unlock the latch (step  710 ). The process ends when the fluid driven cutting tool spindle is spinning at a rate meeting the predetermined access criteria and the latch is unlocked, which means the operator is able to access the interior of the machining center  100  to replace the tool or the workpiece. 
       FIG. 8  shows an example decision tree using the disclosed machining center  100  to adjust the operating parameters thereof. The process may start at step  800 . The wireless sensor  230  is continuously or periodically monitoring or determining the RPM of the shaft or the cutting tool of a fluid driven cutting tool spindle  200  at step  802 . The wireless sensor  230 , alone or in combination with the machining center controller  190  monitors for changes in RPM of the shaft or cutting tool as the spindle is removing material from a workpiece. Monitoring for changes in RPM is shown as step  804 . If no change in speed above a threshold is found, the controller can loop back for another data point from the sensor module that is monitoring the spindle RPM. If the shaft has changed speed above a threshold, the presence of a spike can be determined (step  806 ). A spike is understood as a significant change in speed in a very short amount of time, for example one, two, or less than  10  sampling periods. Spike criteria can define both change in velocity and duration of the change. For example, a change in tool velocity from a working condition to a no load velocity, within a very short amount of time, would be one form of a spike. Similarly, a change in tool velocity from a working condition to a near zero velocity, within a very short amount of time, would be another form of a spike. If a spike, up or down, is found, the controller can signal to stop processing and disable operation (step  808 ). If no spike, i.e. significant change in rotational speed, is sensed, the controller may determine whether the change in rotational speed was an increase or a decrease (step  810 ). The controller may then wish to counteract the change in rotational speed. Therefore, if the rotational speed increased, translational speed can increase to apply more pressure at the cutting insert (step  812 ). Relative translational speed can be increased by increasing the speed of the workpiece or the translational speed of the spindle or both. Alternatively, the fluid pressure applied to the fluid powered cutting tool spindle  200  may be decreased by signaling the appropriate valves and/or pumps. If the rotational speed (RPM) decreased, the translational speed can decrease to reduce pressure at the cutting insert (step  814 ). Relative translational speed can be decreased by decreasing the speed of the workpiece or the translational speed of the spindle or both. Alternatively, the fluid pressure applied to the fluid driven cutting tool spindle  200  may be increased by signaling the appropriate valves and/or pumps. 
     The fluid driven cutting tool spindle  200  in  FIGS. 1 and 2  shows an embodiment specifically designed to accept a unitary sensor module  230  and allow for a through-housing view of the shaft  250 . A wireless monitoring system according to aspects of the present disclosure may be configured for use with other live tools, such as the fluid driven spindle type live tool  900  of  FIG. 9 , that do not provide for through-housing access to the shaft. The wireless monitoring system should still provide for direct monitoring capabilities of the cutting tool operating conditions, such as temperature, vibration, rotational speed, etc. 
     The live tool  900  includes a shaft  902 . The shaft  902  allows the live tool  900  to connect to a machining center ( FIG. 1 ). The shaft  902  may pass through several segments of a live tool body  904 ,  906 ,  907  of varying and successively smaller diameter. The live tool  900  has a smaller diameter towards the cutting end to enable better access to the cutting area. The second live tool body segment  906  is between the first live tool body segment  904  and the third live tool body segment  907  of the illustrated embodiment. In the exemplified case, the first segment  904  is closer to the shaft end of the live tool  900 . The second segment  906  is in between the first and third segments  904 ,  907 , and the third segment is closest to the cutting tool  908 . In other embodiments, each live tool body segment  904 ,  906 , and  907  may have a substantially similar diameter. The cutting tool  908  may be operably connected to the shaft  902  with a collet (not shown). 
     The live tool  900  may include a transmitter unit  910  having a housing with transmitter components, including a power unit, protected inside. The transmitter unit  910  is configured to transmit data to a receiver (e.g.  170  of  FIG. 3 ). In an embodiment, the transmitter unit  910  is a transceiver unit. In an embodiment, the transmitter unit  910  includes computing and/or processing capabilities. As an example, the transmitter unit  910  may include the following elements illustrated in  FIG. 5 : antenna  268 , transmission unit  266 , power source  262  and processor  264 . The transmitter unit  910  may be mounted to the live tool body (e.g. segment  904 ) with a transmitter connector band  920 . There are numerous other methods, known in the art, of mounting auxiliary structures to live tools or related components. In an embodiment, the live tool  900  has at least one feature, such as a cavity (see  FIG. 1B ), a slot, a flat, or a screw thread, that can be used to connect the transmitter unit  910  to the live tool. In each embodiment the live tool  900  does not have to provide for optical access directly between the transmitter unit and the inside of the body  904 . 
     In some embodiments, the transmitter unit  910  uses a cable  930  to connect to a remotely positioned sensor collar  950 . The sensor collar  950  is designed to at least partially surround a rotating portion of the live tool  900  to be capable of monitoring operating conditions adjacent to the cutting tool  908  without dedicated access built into the live tool  900 . The cable  930  can include wiring to transmit power to a sensor within the sensor collar  950  and data from the sensor to the transmitter unit  910 . In one embodiment, a bracket system  940  may be employed to support the cable  930  and/or support the sensor collar  950  upon the live tool  900 . The bracket system  940  may include a connector arm  942  designed to hinge around an axis, exemplified by joint  946 , and provide flexibility in the bracket assembly process. A bracket band  944  may be connected to the live tool body  904 . The connector arm  942  may then extend from the bracket band  944  to the sensor collar  950 . The bracket band  944  may be mounted to a segment of the live tool body  906  different from the segments  904 ,  907  on which the sensor collar  950  and connector band  920  are located. 
     In one example, the sensor collar  950  secures the collet (see  FIG. 10B ) that holds the cutting tool  908 . Therefore the sensor collar  950  may be referred to in the industry as a collet chuck lock nut, such as a Rego fix, a ER lock nut, an ER collet nut, etc. As such, a sensor could be embedded or otherwise provided in a standard body configuration to maintain the functionality and similarly mirror the dimensions of the part (e.g. a ER lock nut) being replaced. For example, the outer diameter range may be between 15-80 mm, more specifically, between 15-20 mm, 20-30 mm, 25-35 mm, 35-50 mm, 50-65 mm, or 60-80 mm. The sensor collar may have a length within the range of about 10-30 mm, more specifically, between about 11-20 mm, or between about 19-30 mm. The sensor collar  950  may be sized to fit ER standards, such as ER11, ER16, ER20, ER25, ER32, ER40, ER50, etc. 
     The sensor collar  950  may include a cavity  952  in which one or more sensors can be mounted or supported within. The cavity  952  may be shaped to position and secure a collet therein. In some embodiments, the sensor collar  950  includes multiple cavities  952  in which multiple sensors can be mounted. The sensor collar  950  may include slots  954 , or similar features, by which a tool can be used to tighten and secure and/or untighten the sensor collar relative to the cutting tool  908  or the shaft  902 . Additional features of the sensor collar  950  include an exterior surface  956 , a tool end distal surface  957 , and a radial interior surface  958 . Thus, the sensor collar  950  has a generally annular shape suitable for at least partially surrounding the cutting tool  908  or the shaft  902 . In some cases the annular shape would be sufficient if it curved only partially around a complete circle. If the sensor collar  950  does not replace a lock nut or similar component, the sensor collar  950  may be a separate element mounted to the housing body  907  by such a locking nut. 
     The sensor collar  950  may house the one or more sensors, and may also house other electrical components in the same annular unit. In an embodiment, electrical traces or wiring are mounted on or within the sensor collar  950 . In an embodiment, sensor collar  950  is or includes a printed circuit board. 
     In other embodiments, the sensors are mounted on, within or integrated with a collet, or a nut system that secures the collet. Typically, the nut system including seals, gaskets, rings and components that are in direct contact with the nut while it is securing the collet in place. In an embodiment, the nut system including components that are placed between the nut and the live tool body  904  such as seals, gaskets, rings, annular shaped or partially annular shaped components. 
     The one or more sensors may be configured to monitor a variety of operating conditions of the live tool  900 . In an embodiment, the sensor may be a speed sensor configured to sense the velocity, or changes therein, of the cutting tool  908  while it is rotating. A change in tool rotational speed, in general, or during various trajectories, may be indicative of tool wear and/or of changes in the cutting process. 
     In an embodiment, the sensor can sense the vibration of the cutting tool  908  in free air and during the machining process. Use of a vibration sensor may allow for a computation or estimation of the rotational speed of the cutting tool  908  without requiring the presence of an optically or magnetically identifiable mark as used by optical and Hall effect sensors. This adds to the ability for the wireless monitoring system to be applied to existing live tools. In an embodiment a piezo electric sensor (e.g. SEN-09198 ROHS or SEN-09196 ROHS) that can measure flex, touch, vibration and shock measurements is mounted on the collar exterior surface  956 , or in the cavity  952 . In an embodiment, a MEMS based accelerometer (such as iSensor® MEMS from Analog Devices) is mounted on the collar exterior surface  956  or in cavity  952 . In an embodiment, the flex and touch features may indicate contact or disengagement of the cutting tool with the work piece. In an embodiment, measurement of the vibration frequency and/or amplitude may be indicative of the cutting process quality. In an embodiment, measurement of the vibration frequency and/or amplitude may be indicative of and correlated to the tool rotational velocity. In an embodiment, a shock signal may be indicative of a hardware problem, such as tool breakage or uncontrolled movement of the work piece. 
     In an embodiment, the sensor is a temperature sensor (e.g. Miniature and Micro Thermistors from QTI Sensing Solutions) configured to sense the temperature of the cutting tool  908  in free air and during the machining process in close proximity to the tool end. Monitoring temperature is worthwhile because an increase in tool temperature may be indicative of tool wear and/or of changes in the cutting process. Sensing temperature can be highly indicative of a pending problem with the cutting process. In an embodiment, the temperature sensor is mounted on the exterior surface  956  of the collar, such that it can sense the cutting environment. In an embodiment, the temperature sensor is mounted in cavity  952  such that it can sense the temperature of the cutting tool during the cutting process. Further, use of a temperature sensor does not require modification to the cutting tool  908  or the shaft  902 . Therefore a temperature sensor is both highly useful for monitoring of the live tool while also promoting the ability to retrofit existing live tools. 
     According to the present disclosure, the live tool  900  is configured for monitoring the cutting tool  908 , or the shaft  902 , directly, at the cutting site, e.g. at the cutting tool or collet. Being “at the cutting site” may mean at the tool end, within a distance of between 1-5 mm, or between 5-10 mm, or between 10-20 mm, or between 20-40 mm. Direct monitoring of the cutting tool  908  includes direct monitoring of the collet that secures the cutting tool and includes directly monitoring the nut that secures the collet. Direct monitoring of the cutting tool  908  also includes direct monitoring of the shaft  902 . The close proximity to the cutting tool  908  limits the potential for interference caused by cooling fluid or mist that can hinder accuracy if the cutting tool  908  were monitored from afar. The transmitter unit  910  provides for wireless communication between the sensor and a control unit of the machine center. 
     Use of wireless communication allows the live tool  900  to remain compatible with automated tool changers (ATC) for being automatically loaded and unloaded. Additionally, the transmitter unit  910  and the sensor collar  950  should be small enough such that they do not compromise the machining process and/or loading and unloading of the live tool  900  from the ATC. 
     In many embodiments, the controller of the machine center is configured to accept the signal or data from the one or more sensors and use that information within a feedback loop to adjust at least one function of the machining center in response to the information related to at least one operating condition received by the wireless receiver. The adjustments may include adjustments to increase or decrease cutting tool velocity, adjustments to terminate the cutting process, or adjustments to regulate access to the machining center. 
     Turning now to  FIGS. 10A and 10B , another live tool  1000 , in this case a mechanical live tool, is shown.  FIG. 10B  is an exploded view of the live tool  1000 . The live tool  1000  is provided with a sensor collar  1050  and a transmitter unit  1010  similar to those discussed above with respect to  FIG. 9 . The wireless monitoring system (e.g. the combination of the transmitter unit  1010  and the sensor collar  1050 ) is applied to the mechanical live tool  1000  without substantial modifications thereto. The live tool  1000  may include a shaft  1002 , a live tool body  1004 , and a transmitter unit  1010 . The live tool body  1004  may have flat surfaces  1015  for engagement by a tool that can be used to mount or dismount the live tool  1000  from the machining center. The live tool body  1004  may also include a threaded portion  1018  for receiving a collar system  1050 . The collar system  1050  may be configured to secure a collet  1020  to the live tool body  1004 . 
     In an embodiment, the collar system includes an annular shaped PCB  1060 , on which sensor elements  1062  are mounted on or within. In an embodiment, the sensor elements  1062  are temperature sensors (such as Miniature and Micro Thermistors from QTI Sensing Solutions). In an embodiment, the sensor elements  1062  are accelerometers to sense vibration, for example Memes based accelerometers (such as iSensor® MEMS from Analog Devices) or piezo electric based sensors (e.g. SEN-09198 ROHS or SEN-09196 ROHS). In an embodiment, the sensor elements  1062  are temperature sensors. In an embodiment the sensor elements  1062  are position and/or velocity sensors that function based on optical or magnetic principles, in which case the cutting tool would have corresponding features such as an optical marking, a physical feature such as a hole or electromagnetic properties, e.g. a magnet. Other types of sensors discussed in the embodiments above may also be included additionally or alternatively. 
     In an embodiment, the sensor elements  1062  are powered from an energy storage unit, for example a capacitor or battery, provided within the collar  1050  or the transmitter unit  1010 . In an embodiment, the collar system  1050  may have a contact point by which the collar system can electrically connect to a reciprocal electrical contact unit when the live tool  1000  is in the ATC. The reciprocal electrical contact unit may be connected to a power source, e.g. to a battery or to the machining center unit power. 
     The collar system  1050  may include a flange  1052 , slots  1054 , or similar features by which a tool can be used to tighten and secure and/or untighten the collar system  1050 . Other features of the collar system  1050  may include an exterior surface  1056  and a radial interior surface  1058 . In an embodiment, the collar system  1050  includes at least one seal  1070  or gasket that is placed on either side of the annular PCB  1060 .Although the above disclosure has been presented in the context of exemplary embodiments, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.