DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant's election with traverse of Group I, claims 1-13 in the reply filed on 06/19/2026 is acknowledged. The traversal is on the ground(s) that Applicant believes that the inventions are similar enough and must be examined together despite being independent or distinct inventions. This is not found persuasive because as pointed out in the Restriction Requirement of 04/21/2026, the two inventions have a process of making and product made relationship, which is properly restrictable per MPEP 506.05(f) and examination of both inventions would result in a burden.
The requirement is still deemed proper and is therefore made FINAL.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-3 and 6-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (CN 112496780, hereinafter ‘Wu’).
Regarding claim 1, Wu discloses an active damper capable of being used in machine spindles comprising a spindle shaft 22/23/2303 having a motor end (far end of 22) opposite an operative end, and a damper portion located between the motor end and operative end. A spindle motor is in operative communication with the spindle shaft proximate the motor end. A damping chamber 23 surrounds the spindle shaft proximate the damper portion, wherein the damping chamber comprises a containment envelope 2304 containing a ferrofluid. At least one damping tab 2305 is attached to the spindle shaft and is located within the damping chamber, the at least one damping tab being in operative communication with the ferrofluid. Electromagnets 2301 are in operative communication with the ferrofluid as well. A spindle position sensor is in operative communication with the spindle shaft, said spindle position sensor being configured to detect a magnitude of motion and relative position of the spindle shaft (Paragraph [0035] of the English translation provided by Applicant). While Wu discloses the active damper existing in a machine tool environment, Wu does not explicitly disclose an endmill in operative communication with the spindle shaft proximate the operative end.
It would have been obvious to one having ordinary skill in the art at the time of filing to provide an endmill in the operative end of the spindle shaft of Wu to enable the spindle shaft to machine workpieces if desired, and to allow the active damping to eliminate any vibrations caused by the machining process.
Regarding claim 2, Wu discloses a control system in operative communication with the spindle position sensor and electromagnets (Paragraph [0035]).
Regarding claim 3, Wu discloses the damping tab being configured to impinge with the ferrofluid such that the ferrofluid can at least one of constrain the movement of the damping tab and allow the movement of the damping tab responsive to the viscosity of the ferrofluid.
Regarding claim 6, Wu illustrates the electromagnets lying just on the other side of a wall 2302 of the ferrofluid containment envelope.
However, rearranging the electromagnets to be inside the containment envelope and in contact with the ferrofluid would have been an obvious modification one having ordinary skill in the art at the time of filing would have made in order to make the damping more effective and eliminate any interference between the electromagnets and ferrofluid. See also MPEP 2144.04, VI, C.
Regarding claim 7, Wu discloses a sealed bearing supporting the spindle shaft proximate a spindle shaft penetration formed through the containment envelope. The spindle shaft is received through the spindle shaft penetration and the sealed bearing is configured to prevent ferrofluid leakage out of the containment envelope along the spindle shaft (Paragraph [0028] and Fig. 3).
Regarding claim 8, Wu discloses an active damper capable of being used in machine spindles comprising a spindle shaft 22/23/2303 having a motor end (far end of 22) opposite an operative end, and a damper portion located between the motor end and operative end. A spindle motor is in operative communication with the spindle shaft proximate the motor end. A damping chamber 23 surrounds the spindle shaft proximate the damper portion, wherein the damping chamber comprises a containment envelope 2304 containing a ferrofluid. At least one damping tab 2305 is attached to the spindle shaft and is located within the damping chamber, the at least one damping tab being in operative communication with the ferrofluid. Electromagnets 2301 are in operative communication with the ferrofluid as well, configured to produce an electromagnetic field that changes the viscosity of the ferrofluid. A spindle position sensor is in operative communication with the spindle shaft, said spindle position sensor being configured to detect a magnitude of motion and relative position of the spindle shaft (Paragraph [0035] of the English translation provided by Applicant). A control system is in operative communication with the spindle position sensor and electromagnets (Paragraph [0035]). While Wu discloses the active damper existing in a machine tool environment, Wu does not explicitly disclose an endmill in operative communication with the spindle shaft proximate the operative end.
It would have been obvious to one having ordinary skill in the art at the time of filing to provide an endmill in the operative end of the spindle shaft of Wu to enable the spindle shaft to machine workpieces if desired, and to allow the active damping to eliminate any vibrations caused by the machining process.
Regarding claim 9, Wu discloses the damping tab being configured to impinge with the ferrofluid such that the ferrofluid can at least one of constrain the movement of the damping tab and allow the movement of the damping tab responsive to the viscosity of the ferrofluid.
Regarding claim 10, Wu discloses many damping tabs lying on the spindle shaft in a circular configuration and evenly spaced (Paragraph [0043]) but does not explicitly disclose orthogonal spacing of first and second damping tabs. However, providing at least a second damping tab orthogonal to the first damping tab (i.e. four damping tabs in 90 degree spacing) would have been an obvious modification one having ordinary skill in the art at the time of filing would have made, to provide stable damping and to not generate torque deflection (see Paragraph [0043]).
Regarding claim 11, Wu discloses ferrofluid lying on the X and Y axes of the damping tab(s) (see e.g. Fig. 3). Accordingly, Wu discloses the first, second and all other damping tabs being oriented relative to each other and configured to influence damping vibration along the spindle shaft in the X and Y axes directions relative to the spindle shaft being a Z axis.
Regarding claim 12, Wu discloses a sealed bearing supporting the spindle shaft proximate a spindle shaft penetration formed through the containment envelope. The spindle shaft is received through the spindle shaft penetration and the sealed bearing is configured to prevent ferrofluid leakage out of the containment envelope along the spindle shaft (Paragraph [0028] and Fig. 3).
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (CN 112496780) as applied to claim 1 above, and further in view of JP 6924513.
Regarding claim 4, Wu discloses the damping tab(s) being rod(s) and does not disclose flow orifices formed therein.
JP ‘513 discloses a similar rotating ferrofluid damper, wherein damping tabs are provided with flow orifices 63 to equalize/compensate pressure (i.e. influence the reaction of the damping tab relative to the ferrofluid).
It would have been obvious to one having ordinary skill in the art at the time of filing to provide the damping tab structure of JP ‘513, including the flow orifices, to the active damper of Wu in order to provide a larger damper tab to be affected by the electromagnets while still allowing the ferrofluid to flow predictably between either side of the tab(s).
Regarding claim 5, Wu discloses the containment envelope containing ferrofluid being sealed closed, such that the ferrofluid is contained and does not flow outside of the containment envelope.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Ito et al. (JP 2020133703) discloses a similar rotary joint that is damped with ferrofluid and electromagnets.
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/Alan Snyder/Primary Examiner, Art Unit 3722
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