ing down from the marginal line, a space of not less than 11/4 inches is to be left blank for the heading of title, name, number, and date, which will be applied subsequently by the Office in a uniform style.

(c) Character of lines. All drawings must be made with drafting instruments or by photolithographic process which will give them satisfactory reproduction characteristics. Every line and letter (signatures included) must be absolutely black. This direction applies to all lines however fine, to shading, and to lines representing cut surfaces in sectional views. All lines must be clean, sharp, and solid, and fine or crowded lines should be avoided. Solid black should not be used for sectional or surface shading. Free-hand work should be avoided wherever it is possible to do so.

(d) Hatching and shading. Hatching should be made by oblique parallel lines, which may be not less than about one-twentieth inch apart.

Heavy lines on the shade side of objects should be used except where they tend to thicken the work and obscure reference characters. The light should come from the upper left-hand corner at an angle of 45°. Surface delineations should be shown by proper shading, which should be open.

(e) Scale. The scale to which a drawing is made ought to be large enough to show the mechanism without crowding when the drawing is reduced in reproduction, and views of portions of the mechanism on a larger scale should be used when necessary to show details clearly; two or more sheets should be used if one does not give sufficient room to accomplish this end, but the number of sheets should not be more than is necessary.

(f) Reference characters. The different views should be consecutively numbered figures. Reference numerals (and letters, but numerals are preferred) must be plain, legible and carefully formed, and not be encircled. They should, if possible, measure at least one-eighth of an inch in height so that they may bear reduction to one twentyfourth of an inch; and they may be slightly larger when there is sufficient room. They must not be so placed in the close and complex parts of the drawing as to interfere with a thorough comprehension of the same, and therefore should rarely cross or mingle with the lines. When necessarily grouped around a certain part, they should be placed at a little distance, at the closest point where there is available space, and connected by lines with the parts to which they refer. They should not be placed upon hatched or shaded surfaces but when necessary, a blank space may be left in the hatching or shading where the character occurs so that it shall appear perfectly distinct and separate from the work. The same part of an invention appearing in more than one view of the drawing must always be designated by the same

character, and the same character must never be used to designate different parts.

(g) Symbols, legends. Graphical drawing symbols for conventional elements may be used when appropriate, subject to approval by the Office. The elements for which such symbols are used must be adequately identified in the specification. While descriptive matter on drawings is not permitted, suitable legends may be used, or may be required in proper cases, as in diagrammatic views and flow sheets or to show materials. The lettering should be as large as, or larger than, the reference characters.

(h) Location of signature and names. The signature of the applicant, or the name of the applicant and signature of the attorney or agent, may be placed in the lower right-hand corner of each sheet within the marginal line, or may be placed below the lower marginal line.

(i) Views. The drawing must contain as many figures as may be necessary to show the invention; the figures should be consecutively numbered if possible, in the order in which they appear. The figures may be plan, elevation, section, or perspective views, and detail views of portions or elements, on a larger scale if necessary may also be used. Exploded views, with the separated parts of the same figure embraced by a bracket, to show the relationship or order of assembly of various parts are permissible. When necessary a view of a large machine or device in its entirety may be broken and extended over several sheets if there is no loss in facility of understanding the view (the different parts should be identified by the same figure number but followed by the letters, a, b, c, etc., for each part). The plane upon which a sectional view is taken should be indicated on the general view by a broken line, the ends of which should be designated by numerals corresponding to the figure number of the sectional view and have arrows applied to indicate the direction in which the view is taken. A moved position may be shown by a broken line superimposed upon a suitable figure if this can be done without crowding, otherwise a separate figure must be used for this purpose. Modified forms of construction can only be shown in separate figures. Views should not be connected by projection lines nor should center lines be used.

(j) Arrangement of views. All views on the same sheet must stand in the same direction and should, if possible, stand so that they can be read with the sheet held in an upright position. If views longer than the width of the sheet are necessary for the clearest illustration of the invention, the sheet may be turned on its side. The space for a heading must then be reserved at the right and the signatures placed at the left, occupying the same space and position on the sheet as in the upright views and being horizontal when the sheet is held in an

upright position. One figure must not be placed upon another or within the outline of another.

(k) Figure for Official Gazette. The drawing should, as far as possible, be so planned that one of the views will be suitable for publication in the Official Gazette as the illustration of the invention.

(1) Extraneous matter. An agent's or attorney's stamp, or address, or other extraneous matter, will not be permitted upon the face of a drawing, within or without the marginal line, except that the title of the invention and identifying indicia, to distingush from other drawings filed at the same time, may be placed below the lower margin.

(m) Transmission of drawings. Drawings transmitted to the Office should be sent flat, protected by a sheet of heavy binder's board, or may be rolled for transmission in a suitable mailing tube; but must never be folded. If received creased or mutilated, new drawings will be required.

See rule 152 for design drawings, 165 for plant drawings, and 174 for reissue drawings.

85. Informal drawings. The requirements of rule 84 relating to drawings will be strictly enforced. A drawing not executed in conformity thereto may be admitted for purpose of examination, but in such case the drawing must be corrected or a new one furnished, as required. The necessary corrections will be made by the Office upon applicant's request and at his expense. (See rule 21.)

86. Draftsman to make drawings.

Applicants are advised to employ competent draftsmen to make their drawings.

The Office may furnish the drawings at the applicant's expense as promptly as its draftsmen can make them, for applicants who can not otherwise conveniently procure them. (See rule 21.)

87. Return of drawings. The drawings of an accepted application will not be returned to the applicant except for signature. A photographic print is made of the drawing of an accepted application.

88. Use of old drawings. If the drawings of a new application are to be identical with the drawings of a previous application of the applicant on file in the Office, or with part of such drawings, the old drawings or any sheets thereof may be used if the prior application is, or is about to be, abandoned, or if the sheets to be used are cancelled in the prior application. The new application must be accompanied by a letter requesting the transfer of the drawings, which should be completely identified.

ent.

MODELS, EXHIBITS, SPECIMENS

91. Models not generally required as part of application or patModels were once required in all cases admitting a model, as a part of the application, and these models became a part of the record of the patent. Such models are no longer generally required (the description of the invention in the specification, and the drawings, must be sufficiently full and complete, and capable of being understood, to disclose the invention without the aid of a model), and will not be admitted unless specifically called for.

35 U. S. C. 114. Models, specimens. The Commissioner may require the applicant to furnish a model of convenient size to exhibit advantageously the several parts of his invention.

When the invention relates to a composition of matter, the Commissioner may require the applicant to furnish specimens or ingredients for the purpose of inspection or experiment.

92. Model or exhibit may be required. A model, working model, or other physical exhibit, may be required if deemed necessary for any purpose on examination of the application.

93. Specimens. When the invention relates to a composition of matter, the applicant may be required to furnish specimens of the composition, or of its ingredients or intermediates, for the purpose of inspection or experiment.

94. Return of models, exhibits or specimens. Models, exhibits, or specimens in applications which have become abandoned, and also in other applications on conclusion of the prosecution, may be returned to the applicant upon demand and at his expense, unless it be deemed necessary that they be preserved in the Office. Such physical exhibits in contested cases may be returned to the parties at their expense. If not claimed within a reasonable time, they may be disposed of at the discretion of the Commissioner.

95. Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from the Office except in the custody of an employee of the Office specially authorized by the Commissioner.

EXAMINATION OF APPLICATIONS

101. Order of examination. Applications filed in the Patent Office and accepted as complete applications (rules 53 and 55) are as

signed for examination to the respective examining divisions having the classes of inventions to which the applications relate. Applications shall be taken up for examination by the examiner to whom they have been assigned in the order in which they have been filed. Applications which have been acted upon by the examiner, and which have been placed by the applicant in condition for further action by the examiner (amended applications) shall be taken up for such action in the order in which they have been placed in such condition (date of amendment).

102. Advancement of examination. Applications will not be advanced out of turn for examination or for further action except as provided by these rules, or upon order of the Commissioner to expedite the business of the Office, or upon a verified showing which, in the opinion of the Commissioner, will justify so advancing it.

Applications wherein the inventions are deemed of peculiar importance to some branch of the public service and the head of some department of the Government requests immediate action for that reason, may be advanced for examination.

103. Suspension of action. Suspension of action by the Office. will be granted at the request of the applicant for good and sufficient cause and for a reasonable time specified. Only one suspension may be granted by the primary examiner; any further suspension must be approved by the Commissioner.

If action on an application is suspended when not requested by the applicant, the applicant shall be notified of the reasons therefor.

Action by the examiner may be suspended by order of the Commissioner in the case of applications owned by the United States whenever publication of the invention by the granting of a patent thereon might be detrimental to the public safety or defense, at the request of the appropriate department or agency.

104. Nature of examination, examiner's action. (a) On taking up an application for examination, the examiner shall make a thorough study thereof and shall make a thorough investigation of the available prior art relating to the subject matter of the invention sought to be patented. The examination shall be complete with respect both to compliance of the application with the statutes and rules and to the patentability of the invention as claimed, as well as with respect to matters of form, unless otherwise indicated.

(b) The applicant will be notified of the examiner's action. The reasons for any adverse action or any objection or requirement will be stated and such information or references will be given as may be useful in aiding the applicant to judge of the propriety of continuing the prosecution of his application.