From Wikipedia (http://en.wikipedia.org/wiki/Perpetual_motion#Patents http://en.wikipedia.org/wiki/Perpetual_motion#Patents): Proposals for such inoperable mac

From Wikipedia (http://en.wikipedia.org/wiki/Perpetual_motion#Patents http://en.wikipedia.org/wiki/Perpetual_motion#Patents): Proposals for such inoperable machines [perpetual mobile] have become so common that the United States Patent and Trademark Office (USPTO) has made an official policy of refusing to grant patents for perpetual motion machines without a working model. The USPTO Manual of Patent Examining Practice states: With the exception of cases involving perpetual motion, a model is not ordinarily required by the Office to demonstrate the operability of a device. If operability of a device is questioned, the applicant must establish it to the satisfaction of the examiner, but he or she may choose his or her own way of so doing.[9] And, further, that: A rejection [of a patent application] on the ground of lack of utility includes the more specific grounds of inoperativeness, involving perpetual motion. A rejection under 35 U.S.C. 101 for lack of utility should not be based on grounds that the invention is frivolous, fraudulent or against public policy.[10]