Where a patentee has reason to believe that his patent is defective by reason of an insuf ficient description in the specifications, or that his claims were not broad enough to include all the principles of his invention, or if there was an error affecting it in the Patent Office. lie may surrender the old patent and at the same time tile an application to have a new one issued to him. upon proper specifications. This is known as 'surrender and reissue' A good patent can not be thus surrendered for the purpose of hav ing a new one containing the features of a subsequent improvement. issued to the inventor. The reissue inust be for the same invention.
Where a claim in a patent covers more than the patentee is lawfully entitled to, the patent is wholly void. however, where this has oc curred through inadvertence or mistake, the patentee may file an instrument known as a 'dixohhner.' which should contain a clear state ment of what he justly claims as his own in vention, and what he disclaims. Unless this is clone, 1 patentee cannot maintain an action to protect whatever rights lie is actually en titled to in the invention. A disclaimer is not the proper method of correcting defective speci fications, as it only amounts to an abandonment I if a thing previously claimed.
Where two or more patents contain claims which are identical, they are known as inter fering patents. In such a case, any one of the patentees may bring all action in equity to have the respective rights of the interfering patentees determined, and only one of the patents can be as valid.
Patents are considered as property, and may he sold and transferred from One person to an other, by assignments in writing. Provision is made for recording such assignments in the Pat ent Oflice, and unless this is done within three months after its date, an assignment will be void as against innocent purchasers or mort gagees for valik. Prospective purchasers should therefore search in the Patent Office for possible assignments. Patents may be held by joint own ers, partners, or corporations. An owner of a patent may convey an interest in it, or grant a license to another to use it upon payment of royalties or a fixed rent, or may grant the right to make and sell it for an agreed period.
All patented articles should be marked with the word 'patented,' and with the exact date on which the patent w•as granted. Unless this is done no damages can be recovered in an action for an infringement, if the infringer had no previous notice of the existence of the patent.
Where an unpatented article is marked 'pat ented.' the person so marking it is liable to a pen alty of not less than $100 and costs, to be recov ered in a qui tam (q.v.) action, one-half of which goes to the informer, and the other half to the overnment.
An infringement of a patent consists in wrong fully making, using, or otherwise dealing with a patented invention. A person to whom the patentee sells a patented machine may make necessary repairs from time to time, but they must not amount to a reconstruction of the ma chine, and he cannot build a new machine with out being guilty of an infringement. Many cases of infringement arise in regard to patented com positions of matter, by an infringer substituting an equivalent for one element. A patentee has two remedies for an infringement. He may sue at law for damages, or may apply to a court of equity for an injunction restraining the infringer from continuing his acts. and incidentally be awarded damages for the. injury suffered. If the patented article is properly stamped, it is no defense that the infringer had not seen or heard of it.
The United States Government will not. issue a patent except with the consent of the patentee, as the relation between them is in a sense con tractual, as the patentee pays certain fees and complies with certain regulations in return for his protection. The grant of a patent is not the grant of a monopoly in the strict sense of that word, which is that certain rights or privi leges theretofore enjoyed by the whole public arc granted exclusively to one or more individuals, and the general public restrained in the exercise of those rights. A patent is merely protection for a limited time in the enjoyment of something which has been created or produced by an inven tor. and which had not theretofore been enjoyed by the general public. Consult the treatises on the Lairs of Patents, by Walker (3 ed.. New York. 1895) ; Phillips (5th ed., Boston. 1867) ; Curtis (4th ed., Boston. 1873) ; Carpmael. Patent Lairs of the World (2(1 ed., London. 11889), and the official Government reports of the 'United States, Great Britain. etc.: Merwin, Patentability of Inventions (Boston, 18831: :Munn & Co.. ("nit(d States Patent Law (New York, 1870). See COPY RIGHT; LETTERS PATENT; MONOPOLY; TRADE MARK.