The Cla.s.sification of Patents.
by United States Patent Office.
PREFATORY NOTE.
Parts A and B of the following pages are designed to acquaint all persons using the Patent Office cla.s.sification with the principles upon which the recla.s.sification is proceeding.
Part C consists of a few tentative rules advanced with the notion of fixing cla.s.sification practice within the office in certain doubtful cases.
Part D is intended to inform examiners recla.s.sifying within examining divisions respecting the initial procedure in reforming a cla.s.s.
THE CLa.s.sIFICATION OF PATENTS
(A) INTRODUCTION.
Cla.s.sification lies at the foundation of the mental processes. Without the power of perceiving, recognizing resemblances, distinguishing differences in things, phenomena and notions, grouping them mentally according to those resemblances and differences, judgment is impossible, nor could reason be exercised in proceeding from the known to the unknown.
The facilitation and abbreviation of mental labor is at the bottom of all mental progress. The reasoning faculties of Newton were not different in qualitative character from those of a ploughman; the difference lay in the extent to which they were exerted and the number of facts which could be treated. Every thinking being generalizes more or less, but it is the depth and extent of his generalizations which distinguish the philosopher. Now it is the exertion of the cla.s.sifying and generalizing powers which thus enables the intellect of man to cope in some degree with the infinite number and variety of natural phenomena and objects. (Jevons, Principles of Science.)
PAST CLa.s.sIFICATIONS OF UNITED STATES PATENT OFFICE.
As under the patent laws the people of the United States a.s.sume all the risks in granting a patent for any means of the "useful arts," a cla.s.sification that will facilitate a judgment respecting the patentability of any means presented to the Patent Office is of peculiar moment. The enormous extent, diversity, and refinement of the useful arts preclude the formation of a judgment on novelty within a reasonable time, unless the necessary comparisons with known processes and instruments have been previously made along the lines that searches must follow and the results of such comparisons made available in a cla.s.sification. The vast majority of available disclosures of the arts occur in patents. Hence the Patent Office cla.s.sification must be adjusted in the main to the a.n.a.lysis, diagnosis, and orderly arrangement of the disclosures of patents.
For more than 80 years United States patents have been cla.s.sified. The first published cla.s.sification, promulgated in 1830, comprised 6,170 patents, divided into 16 cla.s.ses. The change from a registration to an examination system in 1836 instigated a new cla.s.sification in 22 cla.s.ses, including 9,800 patents. The next came in 1868 with 36 cla.s.ses, including about 75,000 patents. On March 1, 1872, a revised cla.s.sification was adopted, comprising 145 cla.s.ses, including 131,000 patents. This cla.s.sification is said to have been planned by Dr. Edward H. Knight. The placing of the patents in accordance with the schedule of cla.s.ses is said to have been done by the several examiners. The cla.s.s arrangement was purely alphabetical by cla.s.s t.i.tles, and the number designations followed the alphabetical order. The names of things to be found in the several cla.s.ses were arranged alphabetically under each cla.s.s t.i.tle. No attempt was made to bring the t.i.tles of allied materials into juxtaposition or to effect other definite arrangement with reference to subject matter in the printed schedules. A consolidated name index supplemented the list of names by cla.s.ses.
This cla.s.sification of 1872 is in part the cla.s.sification that now exists, many of the same cla.s.s numbers and t.i.tles being still in use.
Examiners were apparently permitted to make changes in cla.s.sification to suit their convenience without notice until 1877. In that year a revision of the published schedule was made by a committee, resulting in the addition of 13 new cla.s.ses, and examiners were ordered to transfer patents in accordance with the new t.i.tles. The first cla.s.sification published with distinct subcla.s.ses appeared in 1880. From that time until 1898 the cla.s.sification grew by addition and subdivision of cla.s.ses to suit the ends of individual examiners or in response to supposed exigencies of the work where one division was thought to be overloaded and another underloaded, and the alphabetical arrangement of subcla.s.ses under each cla.s.s has succeeded the alphabetical list of names. The arbitrary correspondence originally established between the alphabetical order of cla.s.s t.i.tles and the numerical order was destroyed as soon as expansion of the cla.s.sification began.
However suitable to the then-existing material of the useful arts the cla.s.sification of 1872 may have been, it failed as fail all inductive processes wherein the generalizations are not broad and deep. (Isaac Newton"s intellect could detect the resemblance between the falling fruit and the motions of the planets.) The cla.s.sification of 1872 was not exhaustive; it failed to recognize to the fullest extent what Bishop Wilkins saw nearly 300 years ago, to wit, that there are "arts of arts;"
and it failed to provide for future invention of new species in the same art, and to recognize that new arts could be formed from combinations of the old.
BEGINNING OF REVISION.
The Cla.s.sification Division was created in the hope that guiding principles of cla.s.sification could be developed and applied for the purpose of amending or revising the cla.s.sification whereby patents could be placed with greater a.s.surance, and whereby the searcher with these guiding principles in mind might find the nearest references. It was confronted with the problem of revising while at the same time keeping accurate record of all changes, correcting all indexes of patents, and using copies in constant demand for search at the same time, necessitating much clerical work, and constant interruption--of correcting rather than planning anew; of mending a machine while constantly increasing duty was required of it.
Ideas on the subject of revision were called for by the Commissioner of Patents, and all in the Patent Office had an opportunity to set forth their notions. The views of one met with approval and in accordance with those views a "Plan of Cla.s.sification" was prepared and promulgated in 1900. What other plans may have been submitted is not now generally known. But in substantial accordance with that published plan, the process of revision has proceeded for more than 14 years until approximately 50 per cent of the patents (including incomplete work) have been placed in revised cla.s.ses.
PRECEDENTS AND AUTHORITIES.
No effective precedents have been found in any prior cla.s.sifications of the arts. The cla.s.sifications of the princ.i.p.al foreign patent offices have not been materially different in principle from the United States Patent Office cla.s.sifications of the past.
The divisions found suitable for book cla.s.sification for library use, have not been deemed adequate to the exactness and refinement essential to a patent office cla.s.sification of the useful arts. The systems of cla.s.s and subcla.s.s sign or number designations of the modern library cla.s.sifications, with their mnemonic significance, afford the most important suggestions to be drawn from library cla.s.sification. None of these systems of designation has been adopted, (1) because of a serious doubt as to the availability of such designations by reason of the length or unwieldiness to which they would attain in the refinements of division necessary in a patent office cla.s.sification, and (2) because of the enormous amount of labor necessary to make the change from present practice.
The best a.n.a.logies are in the known (but changing) cla.s.sifications of the natural sciences, and in them the problems are so different that they can serve only to ill.u.s.trate general principles. The broad principles of cla.s.sification are well understood. The authorities are the logicians from the ancient Aristotle to the modern Bentham, Mill, and Jevons. The effort of the Cla.s.sification Division has been to adapt and apply these well-known principles to the enormously diversified useful arts, particularly as disclosed in patents and applications for patents.
DEFINITION OF SCIENTIFIC CLa.s.sIFICATION.
It may be well to insert here an authoritative definition: "A scientific cla.s.sification is a series of divisions so arranged as best to facilitate the complete and separate study of the several groups which are the result of the divisions as well as of the entire subject under investigation." (Fowler, Inductive Logic.)
Investigation and study of any subject will be facilitated if the facts or materials pertinent to that subject be so marshaled and arranged that those most pertinent to it may appear to the mind in some form of juxtaposition. It is the purpose of the Patent Office cla.s.sification to divide and arrange the body and mult.i.tudinous units of the useful arts so that, having the question of novelty of any defined means to answer, one may with reasonable a.s.surance approach that portion of the rank of arts in which it will be found if it is not new, and in propinquity to which will also be found those means that bear the closest resemblances to that sought for, the resemblances of other units growing less in proportion to their distance therefrom.
Success in the fundamental aim of facilitating adequate search should evidently at the same time reduce proportionately the danger that interfering applications will be overlooked and also effect a distribution of labor favorable to the acquisition of special skill.
(B) PRINCIPLES OF THE NEW CLa.s.sIFICATION OF THE PATENT OFFICE.
THE ELEMENTS OF A PATENT OFFICE CLa.s.sIFICATION.
A cla.s.sification will be useful in proportion (1) to the pertinence to the subject under investigation of the facts selected to be grouped together, or, in other words, in proportion to the appropriateness of the "basis of cla.s.sification" to the subject in hand; (2) to the convenience, stability, and uniformity of the arrangement of the subdivisions whereby the investigator may proceed with reasonable a.s.surance to that portion of the rank of groups within which he will find cognate material; (3) to the accuracy and perspicuity of the definitions of the several divisions and subdivisions; (4) to the completeness and reliability of the cross-referencing and cross-notations; (5) to the uniformity, feasibility, and certainty of the rules by which the accessions of patents disclosing one or several inventions may be diagnosed and distributed to the appropriate divisions of the cla.s.sification in accordance with the basis adopted.
Corresponding to the foregoing a.n.a.lysis the theory of Patent Office cla.s.sification may be treated in five parts: (1) The principles on which the arts shall be divided (basis of cla.s.sification); (2) subdivision and mechanical arrangement of groups; (3) definition; (4) cross-referencing and search-notes; (5) the choice of features by which a patent shall be a.s.signed in the cla.s.sification (diagnosis).
BASIS OF CLa.s.sIFICATION.
The first and most vital factor in any system of cla.s.sification is the basis of division, that is, the kind of characteristics common to any number of objects selected to characterize groups, whereby the individuals of any group will resemble each other for the purpose in view more closely than any individual in any group will resemble any individual in any other group.
"There is no property of objects which may not be taken, if we please, as the foundation for a cla.s.sification or mental grouping of those objects, and in our first attempts we are likely to select for that purpose properties which are simple, easily conceived, and perceptible in a first view without any previous process of thought--but these cla.s.sifications are seldom much adapted to the ends of that cla.s.sification which is the subject of our present remarks." (J. S.
Mill, System of Logic.)
It is clear that a number of objects may be cla.s.sified on several different bases. For example, a number of books could be divided into groups (1) according to the subject of their contents; (2) according to the language in which the books are written; (3) according to the size of page; (4) according to the binding material; or (5) according to the color of the binding. Each of these may be useful cla.s.sifications for some purpose. For the student of literature none is of value except the first; for the connoisseur in bindings, only the last three. A cla.s.sification of animals including cla.s.ses of land animals and water animals would hardly suit a student of zoology, as it would a.s.sociate with the shad and perch such differently organized creatures as the porpoise, whale, and seal. Yet such a cla.s.sification might prove very suitable for a student of fisheries.
_Art as a basis._[1]--So in seeking a basis for a patent office cla.s.sification the purposes of the cla.s.sification should be the guide.
Allegations of ulterior uses[2] (such as may be made merely because the inventor thought of applying his invention to those uses only, or in an effort to get the application examined in a certain division) and other superficial bases should be avoided. That basis will best suit the purpose which effects such an arrangement as will exhibit in suitable groups the "state of the prior art," by which is here meant not necessarily all the instruments of a trade or industry, or all the articles sold by a shopkeeper, as a stationer, but those means that achieve similar results by the application of similar natural laws[3] to similar substances.
As all inventions are made with the ultimate object of satisfying some human desire, the utility of an invention appears to be a natural basis of cla.s.sification. It is apparent, however, that most inventions may contribute to numerous utilities besides the ultimate one. Many processes and instruments intervene between the seed planter and the wheaten rolls upon the breakfast table. The plow may be viewed as an agricultural instrument or as an instrument of civil engineering, according as it is used for preparing the field for planting or rounding a road. A radiating coil of pipe may be thought of as a condenser of steam or of alcoholic vapors, according as it is applied to one material or another; as a cooler or a heater, according to the temperature of a fluid circulated through it. A hammer may drive nails, forge iron, crack stone or nuts. Underlying all of these ulterior utilities, there is a fundamental one to which the normal mind will reach in its natural processes and there rest. The plow loosens or turns over the surface of earth; the coil effects an exchange of heat between its interior and exterior; the hammer strikes a blow. A cla.s.sification of plows in agriculture, road building, or excavating, according to stated ultimate use; of a radiator coil as a steam condenser, still, jacket-water cooler, refrigerator, or house heater; of the hammer as a forging tool, a nail driver, or a nut cracker, appears to separate things that are essentially alike. But cla.s.sifying a plow on its necessary function of plowing, a radiator on its necessary function of exchanging heat, a hammer on its necessary function of striking a blow, evidently results in getting very similar things together. a.s.suming for the moment that utility is a reasonable basis of division of the useful arts, it is deemed more logical to adopt as a basis some utility that _must_ be effected by the means under consideration when put to its normal use rather than some utility that _may_ be effected under _some_ conditions.
Two of the five predictables of ancient logic are property[4] and accident.[5] The capacity of the hammer to strike a blow, the capacity of the radiator coil to exchange heat, are in the nature of properties.
The capacity of the hammer to crack nuts, of the coil to condense steam, are in the nature of accidents--something that follows from the impact and the heat exchange because of the particular accidental conditions of operation. To select an accident as a basis of cla.s.sification is contrary to the laws of thought.
It may be said then that the Patent Office cla.s.sification is based upon "art" in the strict sense in which the word may be said to be used in section 4886, Revised Statutes, but not necessarily in the looser sense of industries and trades. A proper maintenance of the distinction between the word "arts" of the statute and the phrase "industrial arts"
used in the sense of industries and trades is essential to an effective cla.s.sification for the purposes of a patent office search. Similar instruments have been patented in three different cla.s.ses, because of the statements that one was designed for cooling water, another for heating water, another for sterilizing milk; in four different cla.s.ses, because of the statements that one apparatus was to separate solids from the gases discharged from a metallurgical furnace, another to separate carbon from the combustion gases of a steam-boiler furnace, another to remove dust and tar from combustible gas, and another to saturate water with carbon dioxid. Owing to the continuance of a cla.s.sification based largely on remote use, many applications come into the office setting forth inventions of very general application which nevertheless have to be cla.s.sified more or less arbitrarily in one of several arts in which they may be used but to which they are not limited.
_Function or effect as a basis._[6]--Means of the useful arts are related in different degrees. Resemblances selected as bonds for a number of inventions may be more or less close. It is axiomatic that close resemblances should be preferred over looser ones for cla.s.sification purposes. Processes and instruments for performing general operations, such as moving, cutting, molding, heating, treating liquids with gases, a.s.sembling, etc., are more closely bonded than those for effecting the diverse separate successive operations directed toward complex special results, such as making shoes, b.u.t.tons, nails, etc.
Means of the former sort perform an essentially unitary act--the application of a single force, the taking advantage of a single property of matter. Those of the latter sort require the application of several different acts employing frequently a plurality of forces or taking advantage of several properties of matter. In the former case, cla.s.sification can be based on what has been called function, in the latter it cannot be based on function but can be based on what has been called effect (or product).