The present invention relates to media devices. More particularly, the present invention relates to torque measurement of media devices.
The force required to rotate one component about an axis is relevant in a number of industries. For example, precision shaft bearings for aircraft subassemblies, electric air motors, hydraulic and pneumatic pumps, and magnetic tape and disk drives include one or more components requiring torque resistance to be within a predetermined limit. For this reason, test equipment including a torque measurement device, such as a torque gauge or transducer, is employed to measure one component during its rotational movement relative to another component.
Presently, tape cartridges (or tape cassettes or media devices) can include a door to access the magnetic tape within. The tape cartridge door is opened and closed by rotation about a fixed pivot point. The force applied to open and/or close a tape cartridge door should be within a certain range. Excessive force may damage the door or nearby components of the tape cartridge or tape drive. Too little force may be insufficient to close the door.
The force required to operate the cartridge door can be tested using pull-testing equipment. The pull-testing equipment pulls the cartridge door open while measuring forces over a range of door rotation. In
In order to continuously apply the vertical upward force, the pulling mechanism moves along the door 102 in a direction away from the door hinge pivot point 104 as the rotation angle of the door increases. Hence, for each rotation angle, the force is measured at a different distance from the door hinge pivot point 104. For example, when the pulling mechanism is in contact with the door 102 at a point 106, the distance between the point 106 and the door hinge pivot point 104 is D1 and the force measured is F1. When the pulling mechanism is in contact with the door 102 at a point 108, the distance is D2 and the measured force is F2. The distances D1 and D2 are not equal to each other.
The measured distances and forces, which change simultaneously for each rotation angle, must then be converted or interpreted into a format that is usable as torque measurements. The measured forces, for example, may need to be provided in a graphical form to take into account the different distances or the vector force components.
Thus, it would be beneficial to obtain direct outputs of torque measurements during media device door testing. Moreover, a testing system that permits automatic or semi-automatic testing and direct measurements of a plurality of tape cartridges, media devices, and/or one or more open door positions for each tape cartridge would be beneficial.
One embodiment of the present invention relates to a method for measuring operating torque of a media device door. The method includes rotating a door of the media device to at least one angle using an actuator applying force at a contact point on the door. The method further includes sensing torque associated with the door for the at least one angle. A distance from a rotational axis of the door to the contact point is constant over a range of angles of the door. A rotational axis of the actuator is coaxial with the rotational axis of the door.
Another embodiment of the present invention relates to a system for measuring torque of a media device door. The system includes an actuator configured to contact the media device door at a contact point. A distance from a rotational axis of the media device door to the contact point is constant over a range of angles of the media device door. The system further includes a torque sensor configured to measure torque applied to the media device door by the actuator at the contact point. The torque sensor is coupled to the actuator and a rotational axis of each of the actuator and the torque sensor is coaxial to the rotational axis of the media device door.
Still another embodiment of the present invention relates to an apparatus for testing a pivoting door. The apparatus includes an assembly configured to apply a force to the pivoting door in a direction perpendicular to a major plane of the pivoting door to move the pivoting door to a first open position. The assembly contacts the pivoting door at one location on the pivoting door for a range of open positions. The apparatus further includes a torque measurement device configured to obtain a direct torque value associated with the pivoting door at the first open position. The torque measurement device coaxially couples to the assembly along a pivot axis of the pivoting door.
Yet still another embodiment of the present invention relates to a method for manufacturing a media device. The method includes positioning the media device in a torque tester, and rotating a door of the media device to at least one open position. Rotating a door includes applying a force to the door in a direction perpendicular to a major plane of the door, applying the force at one location on the door, and applying the force at a known distance from a rotational axis of the door. The method includes sensing a torque value associated with the door for at least one open position. The method includes determining manufacturing quality of the media device based on the sensed torque value.
Another embodiment of the present invention relates to a method for direct measurement of torque associated with a door. The method includes rotating the door about a rotational axis to at least one open position, and sensing a torque value corresponding to the door for at least one open position along the rotational axis. A force is applied to the door in a direction perpendicular to a major plane of the door, and the force is applied at a constant distance from the rotational axis for a range of positions.
The exemplary embodiment will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, in which:
In the drawings, to easily identify the discussion of any particular element or part, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced (e.g., element 1104 is first introduced and discussed with respect to
The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.
Described in detail below is a system and method for testing a pivoting door of a media device. The amount of torque required to open, for example, a tape cartridge door at one or more angles relative to the reference door position is measured. The torque testing system can utilize conventional torque transducers while providing torque measurements that do not require conversion to be in usable format.
The following description provides specific details for a thorough understanding of, and enabling description for, embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the invention.
Referring to
The tape cartridge holder 204 is coupled to the top of base 202 to position and maintain the housing of the tape cartridge 212 stationary during the test. For example, holder 204 can comprise an “L” shaped configuration against which the tape cartridge 212 abuts.
The interface 206 is coupled to each of the door operating lever 208 and the torque gauge 210. The interface 206 is configured to couple with the door operating lever 208 such that a pivot point of the door operating lever 208 is along the centerline (or rotating axis) of a pivot point of the tape cartridge door 214. The interface 206 is further configured to couple the torque gauge 210 about the centerline of the pivot point of the tape cartridge door 214. The interface 206, lever 208, and torque gauge 210 rotate in unison about the rotating axis of the pivot point of the tape cartridge door 214.
For example, the interface 206 can be provided between the door operating lever 208 and the torque gauge 210. The interface 206 can include a connector or adaptive assembly for coupling the torque gauge 210. The interface 206 is rotationally coupled to the cartridge holder 204 and/or the base 202. The interface 208 may be a circular disk shape with the lever 208 provided on one side and the gauge 210 provided on the other side.
The door operating lever or assembly 208 is configured to contact the tape cartridge door 214 at at least one known constant distance from the pivot point of the door 214. The door operating lever 208 is further configured to open and close the door 214 in response to inputs from an operator. The door operating lever 208 may be a variety of shapes, sizes, and/or contact the door 214 at more than one point. For example, the door operating lever 208 can comprise a rotation bar coupled at one end to the interface 206, and connected at the other end to a contact pin (or contact device). The contact pin contacts the tape cartridge door 214 and determines the fixed distance from the door pivot point to the door opening force. The door operating lever will be discussed in greater detail below.
The torque gauge 210 may be a mechanical torque gauge. The torque gauge 210 may be a conventional torque sensor and/or transducer. The torque gauge 210 may provide a mechanical or electrical output (e.g., torque measurements). The torque gauge 210 is configured to be rotated by an operator to provide the door opening force, specify the desired door open position, and to obtain a direct torque measurement corresponding to that desired position. The torque gauge 210 may comprise a torque transducer and a torque sensor; alternatively, the torque gauge 210 may comprise a combined torque transducer and sensor.
The interface 206 and the door operating lever 208 may collectively be referred to as a fixture or direct torque measurement assembly. The interface 206, the door operating lever 208, and the torque transducer of the torque gauge 210 may collectively be referred to as an actuator. It is contemplated that the system 200 may include other components and/or be provided in alternative configurations.
For example, the torque gauge 210 may be a different type from that shown in
As another example, the door operating lever 208 may be a sleeve-type assembly that fits along at least a portion of the cartridge door 214, such as an edge of the door 214. The amount of contact between the door operating lever 208 and the door 214 is a contact point or a contact area (e.g., a plurality of contact points).
For the system 200, the operator rotates the torque gauge 210 to open the cartridge door 214 to a desired open position or angle. This actuation, in turn, opens the cartridge door 214, via rotation of the interface 206 and the door operating lever 208. The torque that was applied to open the cartridge door 214 to such desired position is the output of the gauge 210. The torque value is provided directly by the torque gauge 210. This torque value may be read directly from the gauge 210 (when the gauge 210 is a mechanical gauge) or from a screen or display associated with the gauge 210 (when the gauge 210 is an electronic or electromechanical gauge).
The system 200 is configured to permit continuous or discrete direct measurements of cartridge door torque relative to a same point of reference, e.g., the door hinge pivot point. Referring to
In
As an example, the cartridge door 214 can open in the range of 0° to approximately 115°. It should be understood that although the axis of the pivot point 216 is shown in
Referring to
The base 502, tape cartridge holder 504, interface 506, and door operating lever 508 are similar to the base 202, tape cartridge holder 204, interface 206, and door operating lever 208, respectively. In
At a fixed distance from the rotational axis of the rotating arm 510, the contact pin 512 is coupled to the rotating arm 510. The contact pin 512 is oriented such that there will be contact with the cartridge door; the force applied by the contact pin 512 to the cartridge door will be in a direction perpendicular to the length of the door 214; and the distance from the rotational axis of the rotating arm 510 to the contact point with the cartridge door is the same for the range of door operation. As an example, the contact pin 512 is configured to contact the inner or underside of the cartridge door. The contact pin 512 lifting or pushing the cartridge door 214 at two different door angles are shown in
In the system 500, the torque sensor apparatus 514 is rotationally coupled to the interface 506 such that the apparatus 514 senses torque measurements with respect to the rotational axis of the cartridge door and a fixed distance defined by the lever 508. The apparatus 514 includes a torque transducer and a torque sensor. As an example, the apparatus 514 can be a torque sensor manufactured by Transducer Techniques, Inc., of Temecula, Calif. The output of the apparatus 514, e.g., direct torque measurements, is provided to a digital panel meter or computer (not shown) for readout and/or recordation.
The apparatus 514 is coupled between the interface 506 and the motor 516. The motor 516 is also configured along the rotating axis of the cartridge door. The motor 516 can be a servo-motor. As an example, the motor 516 can be a brushless 48 Volts motor manufactured by MCG, Inc. of Eden Prairie, Minn.
The amplifier 518 is electrically coupled to the motor 516. The amplifier 516 is configured to receive programmed inputs from an operator or stored program regarding the cartridge door testing parameters (e.g., desired door open angles). The amplifier 518 outputs appropriate servo signals to the motor 516. As an example, the amplifier 518 can be a PWM servo amplifier manufactured by Advanced Motion Controls of Camarillo, Calif.
As shown in a top view of the system 500 in
It is understood that the system 500 includes various connectors, support brackets, etc. to couple and/or position the components relative to each other. For example, the tape cartridge holder 504 can include a cartridge casing abutment portion and a tension portion to securely hold the tape cartridge there between. The interface 506 can include a counter weight to balance the load to the interface 506 caused by the cartridge door during door operation.
The motor 516 is configured to cause opening of the cartridge door 214 to a desired position, and the corresponding amount of torque is measured by the torque sensor apparatus 514. Continuous or discrete torque measurements over a range of open positions are possible via control of the motor 516. The motor 516 can be programmed to open the cartridge door at one or more desired positions. The torque measurements are provided in real-time or approximately in real-time. These torque measurements can be readout via a digital meter (or gauge), stored in a database (or spreadsheet), and/or analyzed. In any case, because the torque measurements are relative to the same points of reference (e.g., a constant perpendicular distance from the door hinge pivot point and the force in the perpendicular direction only), the obtained data are immediately usable and meaningful. There is no need to convert or deconstruct the measured data to actually obtain torque measurements (e.g., conversion of force measurements into torque measurements).
The system 200 or 500 may be configured to measure torque from a closed (or almost closed) door position to one or more open door positions. Alternatively, the system 200 or 500 may be configured to measure torque from a first open door position to a second open door position. The first open door position may have a smaller or larger door angle than the second open door position.
In this manner, tape cartridges are tested for manufacturing consistency, operability, and/or compatibility with tape cartridge handling devices. The torque required to open the tape cartridge door at one or more open positions is directly measured. The interface 206 of the system 200 can be indexed (or otherwise notated) to indicate when the cartridge door has been opened to desired test position(s). This may be useful when it is desired to test torque at particular door angles for every cartridge, e.g., half way open and fully open positions. For the interface 506 of the system 500, the motor 516 can be programmed to test torque at particular door angles for every cartridge. Hence, test or measurement uniformity and repeatability is possible across many tape cartridges.
The testing scheme can also be fully automated such that tape cartridges can be loaded, tested, removed, and/or torque measurements stored or analyzed without operator assistance. For example, the system 200 or 500 may be implemented with a robotic arm or assembly line scheme where random or every tape cartridge is tested prior to packaging. Because torque measurement is the direct output and is practically provided in real-time in the systems 200 and 500, the cartridge door torque check can quickly determine if a given tape cartridge meets quality control during the manufacturing process.
In alternative embodiments of the system 200 or 500, torque associated with devices other than tape cartridges may be tested. The alternate device could be a drive device that includes a pivoting door. As another example, the alternate device may be a drive bezel containing a pivoting door. The alternate device could also be a tape cassette having a pivoting door, such as those including a single reel or dual reels. The alternate device may also be a magnetic or optical recording medium, other storage mediums, or data storage recording or readout devices. Collectively, devices or mediums that may be tested using the system 200 or 500 are referred to as media devices.
The tape cartridge holder 204 (or 504) and/or the lever 208 (or 508) can be modified to position the rest of the system for direct torque measurements of devices other than tape cartridges. For example, the rotating arm 500 may be shortened or lengthened to achieve the desired distance between the door pivot axis and contact point. As another example, the contact pin may comprise an “L” shaped contact pin and contact the door perpendicular to the major plane of the door when the door pivots inwardly into the media device.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, although a certain type of tape cartridge may be discussed herein, other types of tape cartridges or media devices may be tested. Accordingly, the invention is not limited except as by the appended claims.