Motors: expansible chamber type

SECTION I - CLASS DEFINITION

This class is limited to motors for converting the energy of a pressure fluid into mechanical work in which a charge of simple pressure fluid is admitted to an expansible chamber, the expansion of said chamber converting into work only the original energy of the charge, the charge after expansion of said chamber being exhausted to some place other than whence it came, and in which no energy is extracted from the charge except by expansion of the chamber, said motors when of the reciprocating or oscillating type including control of the fluid.

(1) Note. Claims Not Controlling in Patents Prior to 1936. Patents issued prior to 1936 have not necessarily been classified by claims so that the placement of these patents does not necessarily indicate lines of classification. However, most of the patents regardless of their age have been placed in accordance with their claimed subject matter. PLACEMENT OF PATENTS A. Involving Combination and Subcombination Subclasses: In many instances the schedule of this class provides for a combination which requires a given subcombination, and elsewhere below provides for the subcombination. The following rule has been followed as to the placement of the original patent, and as to cross-referencing, and should be followed in the future. Where the combination subclass requires the same subcombination as is provided for in the subcombination subclass, i.e., subcombination defined with the same specificity in both subclasses, a patent disclosing the combination is placed as an original in, or under, the combination subclass regardless of whether the claims are directed to the combination or subcombination and is not cross-referenced to the subcombination subclass. A patent disclosing only the subcombination and claiming same is placed as an original in the subcombination subclass and is not cross-referenced to the combination subclass. This rule is applicable only in instances where there is but a single subcombination subclass, i.e., no indented subclasses, but the combination subclass may be further subdivided into indented subclasses. The prime feature of this situation is that the subcombination must, by definition, be of equal specificity in the two subclasses. A search for the subcombination, at least in the case where it is adapted to be used in the combination, of necessity involves all of the patents in the combination subclass. Under this system of placing the patents a complete search of the combination can be made in the combination subclass, and of the subcombination in both subclasses without the addition to the search files of the otherwise necessary cross-reference copies. The subclasses involved in this combination-subcombination relationship have been indicated in the schedule by numbers in parenthesis, as explained in a paragraph after the class title. Exemplary of this situation in the indented subclasses (223-229) provide for a distributor (valve) in the piston of a cyclically operable motor combination while subclass 422 requires only a valved piston subcombination. As between these subclasses any patent having a disclosed cyclically operable motor is placed as an original in subclass 222 or one of the indented subclasses regardless of whether the means which makes the motor cyclically operable is claimed and is not cross-referenced in subclass 422. A complete search for the subject matter provided for in subclass 422 of necessity involves all of the patents in subclasses 222-229. B. Involving Ancillary or Auxiliary Expansible Chamber Motor: In many instances the claimed motor which provides the basis of classification for a patent in Class 91 is provided with another expansible chamber motor which merely performs an ancillary or auxiliary function for the main motor. Illustrative of such functions are motor valve or lock, or lubricator actuation. In such cases the structure or operation of the ancillary motor does not constitute a basis for original classification of the patent in the Class 91 schedule unless the patent includes a claim to the auxiliary motor, per se. However, the patent may be cross-referenced on the basis of the auxiliary motor. For example, see subclasses 6-33 and 282-283. Subclasses 6-33 provide for fluid supply through diverse paths to a single expansible chamber. In this case the chamber must be a chamber of the motor which causes the patent to be classified in Class 91. Subclasses 282-283 provide for the same type of supply to a motor chamber, but in this case the motor is an auxiliary motor in that it actuates the distributor of another motor. This type of control of a distributor motor does not cause classification of the patent as an original in subclasses 6-33, but cross-reference to subclasses 6-33 is appropriate.