Definition

(A) This class relates to devices which include an expansible chamber, said chamber having a wall portion thereof (i.e., a working member) movable in a to and fro motion to vary the volume of the chamber, and having a fluid conducting passage means in communication with the chamber for introducing or withdrawing fluid therefrom, said device being the type in which:

(1) The introduction of fluid into the chamber or the withdrawal of fluid from the chamber acts upon the movable wall portion and effects a movement thereof in a direction to change the volume of the chamber and produce a mechanical force output which is employed to do work (e.g., motor) or

(2) Application of a mechanical force to the movable wall portion effects a movement of such movable wall portion in a direction to change the volume of the chamber to draw fluid into or expel fluid from the chamber (e.g., pump).

(B) This class also takes miscellaneous subcombinations of motors or pumps disclosed as being of the type having a chamber as indicated in part A, above, not involving control of the working fluid and not provided for in other classes, (e.g., bellows walls, diaphragms or pistons).

(C) This class excludes means to control the fluid to or from the chamber, except in the case of a sealing means for a working member which is adapted under certain conditions of operation to flex away from the encompassing chamber wall to allow fluid passage between said means and the chamber wall.

(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. STATEMENT RELATING TO PLACEMENT OF PATENTS 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 the 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. See Lines With Other Classes and Within This Class, below for the exemplary of this situation in the Class 92 schedule.

Lines with other classes and within this class

EXEMPLARY IN THE CLASS 92 SCHEDULE

Exemplary of this situation (as described in the Class Definition, above) in the Class 92 schedule are subclasses 11 and 12. It is noted that subclass 11 provides for a working member combined with means to control the flow of nonworking arresting fluid therefor in which said flow control means is responsive to the position of the working member and an auxiliary adjustable throttle for further controlling such flow while subclass 12 merely requires an adjustable throttle for controlling such flow. As between these subclasses a patent having a disclosed means responsive to the position of the working member for controlling the flow of nonworking arresting fluid for a working member combined with an auxiliary adjustable throttle is placed as an original in subclass 11, whether or not working member position control means is claimed and is not cross-referenced in subclass 12. A complete search for the subject matter provided for in subclass 12 of necessity involves all of the patents in subclass 11.

COMBINATIONS WITH LOAD DEVICES Inasmuch as a mechanical force output of an expansible chamber device within the definition of this class is to operate or move a load the inclusion of the load in the claim by name only or in general terms will not exclude a patent from this class. An exception to this general rule exists where the load on the expansible chamber device is a valve. The combination of an expansible chamber device and a valve as the load moved thereby, even if the valve is claimed by name only, is excluded from this class and will be found in Class 137, Fluid Handling, or Class 251, Valves and Valve Actuation. This line also applies where the load is a tool: that is, a named tool moved by the expansible chamber will not exclude a patent from this class if no tool details are recited. However, if a support for the work being acted upon by the tool is claimed, classification in the appropriate tool class results even though both the tool and the support are claimed by name only. Also see Search Class 173 note in References to Other Classes, below, for the line with regard to a nominally claimed tool driven by an expansible chamber device combined with other features such as work cleansing or tool feeding. No attempt has been made to review the classification of all patents found in classes relating to loads adapted to be moved by an expansible chamber device. Thus, it is to be noted that the original classification of all patents is not consistent with the above statement as to nominally claimed loads and this particularly applies as to classes not recently reclassified. In those instances in which a body of art is known to exist in a given class in which the load adapted to be moved by the expansible chamber device is claimed only nominally, and especially where the classification of that class provides for a fluid pressure actuator for the device, currently issuing patents will not be classified as originals in Class 92 even though the load is only nominally claimed. The means which transmits power from the working member of the expansible chamber device to the load to be moved (e.g., linkage, gearing, etc.) is not considered to be the load to be moved by the expansible chamber device. See References to Other Classes, Search Note to Class 74, for a discussion of this subject. RELATIONSHIP TO CLASS 91. For the relationship between this class and Class 91, see "(3) Note" in the class definition of Class 91. RELATIONSHIP TO CLASS 60 Class 92 is directed to expansible chamber devices per se of the type which includes an oscillating or reciprocating working member and is generally related to Class 60, as a subcombination of a Class 60 device of the type which includes an expansible chamber. More specifically the line may be categorized as follows: A. PLURAL OR COMBINED WITH A MOTOR (1) The combination of an expansible chamber device of the type set forth in part (A), (1), of the class definition above combined with a motor of a different type is classified in Class 60. However, the combination of a Class 92, Expansible Chamber Devices with a motor which performs work solely for use by the expansible chamber device (e.g., move the working member, or adjust a part thereof) is classified in Class 92. The combination of a plurality of Class 92, Expansible Chamber Devices having a plurality of working members (e.g., pistons) is classified in Class 92. B. WORKING FLUID SOURCE, MODIFICATION OR EXHAUST TREATMENT (1) Pumps. The inclusion in a claim of a pump broadly which provides motive fluid for utilization by the Class 92, Expansible Chamber Devices does not preclude classification in Class 92. The following examples have been considered to be nominal inclusion of a pump and if so claimed would not preclude classification in Class 92: (a) a pump; (b) a rotary pump; (c) a motor driven pump; (d) a motor driven rotary pump; (e) an internal combustion engine having an intake manifold (as a source of vacuum); (f) a plurality of pumps arranged in parallel; (g) a circuit comprising a sump, pump and expansible chamber device. The following examples have been considered to be significant inclusion of a pump and if so claimed would preclude classification in Class 92 and cause classification in Class 60, if otherwise appropriate: (a) a pump which is characterized as to type, e.g., centrifugal, eduction, constant displacement, variable displacement, pulsator, etc. (however, see (b) in the preceding paragraph) (b) a motor driven pump in which the motor is characterized as to type, e.g., turbine, electric motor, internal combustion engine (however, see (e) in the immediately preceding paragraph) (c) a pump which has any detail thereof recited as, for example, a "piston" (d) a plurality of pumps in series (e) a particular physical relation between a nominal pump and (1) a motor supplied thereby or (2) with a sump, reservoir or tank forming part of the circuit supplying the pump. For example, this particular physical relation may include their relation in space or mechanical interconnection means. See particularly Class 60, subclasses 325+. (2) Accumulators. An expansible chamber device in constant communication with an accumulator for pressurized working fluid is not precluded from Class 92 regardless of the specificity with which the accumulator is recited, the accumulator in this case being considered to be merely a part of the expansible chamber. (3) Internal Generation. Class 60 takes an expansible chamber device in which the working fluid within the expansible chamber device is heated or cooled, as, for example, by a fluid in heat exchange relation with the interior of the chamber. Such fluid may be the same working fluid used in the chamber either before or after it passes through the chamber. However, a mere heat exchange space or jacket associated with the chamber through which a heat exchange fluid may be circulated is not excluded from Class 92, unless some means are provided to control the flow of heat exchange fluid into or out of the space or jacket. See Class 60, subclass 508. (4) Heating, Superheating or External Generation An expansible chamber device having a nominally claimed means to heat or superheat the working fluid before introduction into the expansible chamber is not precluded from Class 92. For example, Class 92 takes a boiler combined with an expansible chamber device while a "fire tube boiler" combined with a Class 92 expansible chamber device would be classified in Class 60. See, for example, Class 60, subclasses 643+. Class 92 does not take the combination of an expansible chamber device with an explosive generation of working fluid even if nominally claimed. See, for example, Class 60 subclasses 632+. (5) Exhaust Treatment or Handling Class 60 takes combinations involving treatment of motive fluid after it leaves an expansible chamber where means is claimed to change some characteristic of the fluid. A condenser, muffler or filter are examples of such means, but the inclusion of a condenser, muffler or filter in a claim by name only is not sufficient to preclude a patent from Class 92. Class 60 also takes combinations involving handling of exhaust fluid from a fluid motor. Handling is considered to necessarily include more than a mere pipe or chamber to conduct the exhaust fluid away. However, an exhaust fluid conductor having a number of ports therein merely for the purpose of dividing the exhaust stream is more than a mere chamber or pipe and is classified in Class 60. Claimed limitations to an elbow, support or other fitting which constitutes a mere part of the exhaust pipe will be ignored, but any significant relation of the pipe and expansible chamber device will result in classification in the appropriate exhaust treatment subclass of Class 60. A particular physical relation or mechanical inter-connection between a chamber or reservoir for receiving exhaust fluid from the motor and the motor has been considered exhaust handling for Class 60. See Class 60, subclasses 272+ and 685+. C. PULSATORS Class 60 takes a pulsator system in which a generally constant mass of confined working fluid is moved by the working member of one expansible chamber device to effect movement of the working member of said expansible chamber device. Where only one of the expansible chamber devices forming a pulsator system is claimed, classification is generally in Class 92. However, see (3) Note of the definition of subclasses 533+ of Class 60 for a list of pulsator elements or subcombinations classifiable in Class 60.