Reference will now be made in detail to the alternative embodiment(s) of the present invention. While the invention will be described in conjunction with the alternative embodiment(s), it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.
Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. For example, it should be understood that although the discussion will refer to lubricating fluid on screws, such specificity is merely for convenience and to simplify the discussion. As such, the methods and systems of the embodiments of the present invention can be applied to any object with a fluid disposed thereon.
Incoming screws 310 represent a batch of HDD screws that will ultimately be used in HDDs if “passed” by lubricating fluid quantity testing system 340. After the batch of screws is compiled, incoming screws 310 enter washing system 320. In one embodiment, incoming screws 310 enter washing system 320 to remove any dirt, grease, lubricating fluid, or the like. It should be appreciated that the removal of undesirable deposits improves the accuracy and precision of quality control system 300, and thus, improves the quality of its pass/fail determinations. After incoming screws 310 are washed in washing system 320, lubricating fluid is applied by lubricating fluid application system 330. The amount of lubricating fluid applied to incoming screws 310 may then be measured by lubricating fluid quantity testing system 340.
In one embodiment of the present invention, one or more of the screws are selected from the batch to be tested by lubricating fluid quantity testing system 340. The screws are passed if the amount of lubricating fluid applied to the screws under test falls within the desired range, and failed if the amount of lubricating fluid falls outside of the desired range. If failed, the screws are sent back to washing system 320 to be rewashed, then to lubricating fluid application system 330 to be recoated, and finally back to lubricating fluid quantity testing system to be retested. If the batch of screws passes, then the batch, excluding those screws under test, are sent to HDD assembly lines 350 for use in the assembly of HDDs.
To summarize the operation of quality control system 300, a batch of HDD screws enters quality control system 300 as incoming screws 310, is washed in washing system 320, is coated with lubricating fluid in lubricating fluid application system 330, and then one or more screws selected from the batch of incoming screws 310 is tested in lubricating fluid quantity testing system 340. If the screws tested are passed, the batch of screws is passed on to HDD assembly lines 350 for use in the assembly of HDDs. If the screws tested are failed, then the batch is sent back to washing system 320 to be rewashed, then passed to lubricating fluid application system 330 to be recoated with lubricating fluid, and then passed to lubricating fluid quantity testing system 340 to be retested. In one embodiment, this process is repeated until the batch is passed.
It should be appreciated that in one embodiment, lubricating fluid quantity testing system 340 utilizes a destructive testing method. As such, after comparing the measured amount of lubricating fluid applied to the screw or screws under test to a desired value or range of values, all of incoming screws 310 except for those under test are either passed or failed.
Referring to
After being weighed in weighing system 420, weighed screws with lubricating fluid 430 enter heating system 440. Heating system 440 heats weighed screws with lubricating fluid 430 at a substantially constant temperature until all lubricating fluid is removed. It should be understood that a substantially constant temperature may include slight variations from the substantially constant temperature throughout heating. Moreover, it should be understood that this substantially constant temperature is maintained from the point at which heating is initiated.
In one embodiment, heating system 440 utilizes an oven preheated to a desired temperature. In this embodiment, weighed screws with lubricating fluid 430 are placed in the preheated oven until all lubricating fluid is removed. In another embodiment, heating system 440 utilizes a micro-flame jet. The micro-flame jet is directed toward weighed screws with lubricating fluid 430 until all lubricating fluid is removed. In each of these embodiments of the present invention, the time required to remove the lubricating fluid is greatly reduced since the heat source is not heated from room temperature. Consequently, the time to test weighed screws with lubricating fluid 430 is reduced substantially as compared to conventional systems. For example, in one embodiment, the testing time is reduced from about 30 minutes to about one minute.
Moreover, embodiments of heating system 440 of the present invention allow the heating of multiple screws, which significantly reduces the time required to remove the lubricating fluid. For example, instead of taking five hours to heat ten screws as required by conventional systems, one embodiment of present invention can heat the ten screws in as little as one minute if heated simultaneously or as little as ten minutes if heated individually. In other embodiments, the time to heat screws may be even further reduced. Thus, embodiments of the present invention significantly reduce the time it takes to heat one or more screws until all the lubricating fluid disposed thereon is removed.
Once the lubricating fluid is removed via heating system 440, processed screws without lubricating fluid 450 are then reweighed in weighing system 420 to determine the amount of lubricating fluid removed from the screws. In one embodiment, the screws are weighed individually. In this embodiment, the weight of the screw after the lubricating fluid is removed is subtracted from the weight of the screw obtained previously when the screw was coated with lubricating fluid. The result represents the amount of lubricating fluid removed from the screw. In another embodiment, the screws are weighed simultaneously. In this embodiment, the weight of the screws after the lubricating fluid is removed is subtracted from the weight of the screws obtained previously when the screws were coated with lubricating fluid. This result may then be divided by the number of screws to obtain an average value for the fluid removed from each screw. In either embodiment, once the amount of fluid on each screw is determined, this value is then compared to a range of acceptable values to determine if the batch, represented by the sample screws tested, passes or fails. Failed screws 460 are rewashed and recoated with lubricating fluid before being retested. Passed screws 470 are sent to the HDD assembly lines for use in assembly of HDDs.
Referring again to
In step 505 it is determined whether the amount of lubricating fluid disposed on the selected screw or screws falls within an acceptable range. If the amount of lubricating fluid is not acceptable, then the whole batch, excluding the screw or screws tested, is rewashed, recoated, and re-measured in accordance with steps 502, 503, and 504. If the amount of lubricating fluid is acceptable, then the whole batch, excluding the screws tested, is sent to HDD assembly lines (e.g., HDD assembly lines 350 shown in
Referring to
In step 602, the weighed object or objects are heated at a substantially constant temperature until all fluid disposed on the object or objects is removed. The heating in step 602 is performed in one embodiment by a heating system (e.g., heating system 440 shown in
For example, in one embodiment, heating system 440 utilizes an oven preheated to a desired temperature. In this embodiment, weighed screws with lubricating fluid disposed thereon are placed in the preheated oven until all lubricating fluid is removed. In another embodiment, heating system 440 utilizes a micro-flame jet. The micro-flame jet is directed toward weighed screws with lubricating fluid disposed thereon until all lubricating fluid is removed. In both of these embodiments of the present invention, the time required to remove the lubricating fluid is greatly reduced since the heat source is not heated from room temperature.
Consequently, the time to test weighed screws with lubricating fluid disposed thereon is reduced from about 30 minutes in some conventional systems, to about one minute with embodiments of the present invention. Moreover, embodiments of heating system 440 of the present invention allow the heating of multiple screws, which significantly reduces the time to remove the lubricating fluid. For example, instead of it taking five hours to heat ten screws with a conventional system, embodiments of present invention can heat the ten screws in as little as one minute if heated simultaneously or as little as ten minutes if heated individually. Thus, embodiments of the present invention significantly reduce the time it takes to heat one or more objects until all the fluid disposed thereon is removed.
In step 603 of
In step 604, in one embodiment the objects can be weighed individually and the weight of the object after the fluid is removed can be subtracted from the weight of the object obtained previously when the object was coated with fluid. The result represents the amount of fluid on the object. In another embodiment the objects can be weighed simultaneously and the weight of the objects after the fluid is removed can be subtracted from the weight of the objects obtained previously in step 601 when the objects were coated with fluid. This result is then averaged such that the amount of fluid disposed on each object is estimated.
The results shown in
The alternative embodiment(s) of the present invention are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.