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Publication numberUS587907 A
Publication typeGrant
Publication dateAug 10, 1897
Publication numberUS 587907 A, US 587907A, US-A-587907, US587907 A, US587907A
InventorsWilliam L. Ames
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Piston for rotary pumps
US 587907 A
Images(1)
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Description  (OCR text may contain errors)

(No Model.)

W L AMES & T GRAY PISTON FOR ROTARY PUMPS, BLOWERS, &c.

No. 587,907. Patented Aug. 10,1897.

71 12172656 5. J/ZMM 7 UNITED STATES PATENT OFFICE.

WILLIAM L. AMES AND THOMAS GRAY, OF TERRE HAUTE, INDIANA.

PISTON FOR ROTARY PUMPS, BLOWERS, 800.

SPECIFICATION forming part of Letters Patent No. 587,907, dated August 10, 1897. Application filed July 8, 1893. Serial No. 479,976. on model.)

T0 ail whom it may concern:

Be it known that we, WILLIAM L. AMES, a citizen of the United States, and THOMAS GRAY, a subject of the Queen of Great Britain, residing at Terre Haute, in the county of Vigo and State of Indiana, have invented certain new and useful Forms of Pistons or Revolvers for Rotary Pumps, Blowers, Gas-Exhausters, Meters, and the Like, of which the following is a specification. p

The object of our invention is to provide pistons of the class mentioned which have such an outline of cross-section, taken at right angles to the axis of rotation, that they may either be made with greater accuracy or with less labor than the pistons now in use for such purposes, or that the form of cross-section may be adapted to specific purposes, or that either one or all these advantages may be obtained. We accomplish these results by making use of odontoidal surfaces, so arranged as to form a working surface for a rotary piston, which'under proper conditions is coacting with another piston the working surface of which has a like form.

By odontoidal surfaces we wish to be understood as meaning surfaces of such contour that when they have their axes of rotation in proper position and are rotated about these axes with proper and uniform angular velocities they will keep in perfect contact continuously throughout the extent of the coacting pairs of surfaces.v Our method of arrangement and construction of these surfaces is illustrated in the accompanying drawing,

which represents the cross-section of a pair of pistons, the section-outline being generated by rolling outside and inside the pitchcircle a closed curve of unequal diameters.

Describing our invention more fully by aid of the drawing, the outline of the piston-section is generated in like manner to that of the continuous epicycloidal outline generated by alternately rolling a'circle on the inside and outside of the pitch-line, but differs therefrom in that the rolling or generating curve is not a circle, but has unequal diameters.

As a particular case the drawing represents a section-outline 35 36, generated by rolling on the pitch-circle an ellipse Z, having its perimeter equal to one-fourth that of the pitch-circle and (in this case) having the describing point at the end of the major axis. When a piston of this outline is used in conjunction with a piston of like outline, perfect contact is kept up throughout a complete revolution.

By properly selecting the describing point (which may be any point of the rolling curve) the outline of the section may be varied to suit certain particular applications. For example, by taking the describing point at the end of the major axis of the ellipsealong and relatively thin section is obtained,thus adapting the pump to a larger capacity for low pressures. By taking the describing point at the endof the minor axis ashort and broad section is obtained which may be made to swell around the shaft, thus permitting the use of a large shaft and adapting the pump to high pressures.

Although we have used the ellipse as a particular case of rolling or generating curve for describing our invention, we do not confine ourselves to the use of the ellipse, but may use any other suitable closed curve excepting the circle.

Having fully described our invention, what we claim, and desire to secure by Letters iatent, is

Rotary pistons having as section-outlines odontoidal curves generated by rolling outside and inside the pitch-circle-a closed curve having unequal diameters-and having a periphery equal to one-fourth that of the pitchcircle, substantially as described.

WM. L. AMES. THOMAS GRAY;

Witnesses:

' P. NIELSEN,

EDWIN FAUST.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3050011 *May 20, 1959Aug 21, 1962Martin KarlRotary pump
US3089638 *Dec 1, 1958May 14, 1963Dresser IndImpellers for fluid handling apparatus of the rotary positive displacement type
US4975032 *Jun 29, 1988Dec 4, 1990Fuji Jukogyo Kabushiki KaishaRoots type blower having reduced gap between rotors for increasing efficiency
US7188621Aug 4, 2004Mar 13, 2007Pulmonetic Systems, Inc.Portable ventilator system
US7527053Mar 23, 2005May 5, 2009Cardinal Health 203, Inc.Method and apparatus for attenuating compressor noise
US7607437May 18, 2004Oct 27, 2009Cardinal Health 203, Inc.Compressor control system and method for a portable ventilator
US7997885Mar 18, 2008Aug 16, 2011Carefusion 303, Inc.Roots-type blower reduced acoustic signature method and apparatus
US8118024Jul 13, 2006Feb 21, 2012Carefusion 203, Inc.Mechanical ventilation system utilizing bias valve
US8156937Sep 23, 2005Apr 17, 2012Carefusion 203, Inc.Portable ventilator system
US8297279Jun 2, 2006Oct 30, 2012Carefusion 203, Inc.Portable ventilator system
US8522780Mar 1, 2007Sep 3, 2013Carefusion 203, Inc.Portable ventilator system
US8627819Jun 2, 2006Jan 14, 2014Carefusion 203, Inc.Portable ventilator system
US8677995Oct 23, 2007Mar 25, 2014Carefusion 203, Inc.Compressor control system for a portable ventilator
US8683997Oct 31, 2007Apr 1, 2014Carefusion 203, Inc.Portable ventilator system
Classifications
Cooperative ClassificationF04C2/084