US1475662A

US1475662A - Method of finishing piston-ring grooves

Info

Publication number: US1475662A
Application number: US570020A
Authority: US
Inventors: George A Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-06-21
Filing date: 1922-06-21
Publication date: 1923-11-27
Anticipated expiration: 1940-11-27

Description

Nov 27 1923, 1,4?5fi62 G. A. TAYLOR METHOD OF FINISHING PISTON RING GROOVES Filed June 21.. 1922 INVEN+UVZ consists that all the grooves of Patented Nov. 27, 19230 GEQBG-E A. TAYLOR, 01E EOS' I'ON, SACHUSETUES.

METHQJD 0E FINISHING- PISEQN-MNG GEQQVES.

Application filed June all, 1922'. denial the. aroma To all whom it may Be it .lniown that ll, Gannon A. 'la. me; a citizen of the United States, residing at Boston, county of Suolk, State of -Massachusetts, have invented a certain new and useful Improvement in Methodsol. Finishing Piston-Ring Grooves, of which the following is a specification, reference being had therein to the accompanying drawin.' My invention relates to the manuacture of pistons for internal combustion engines and like articles which are provided with annular slotsin which the piston rings are placed. It is important that the, parallel walls of these slots shall be true, ot the correct distance apart, and as highly. finished as possible, so that a gas tight seat shall be made between the proximate faces of the ring and groove. My present invention, therefore, has for its object a novel method of enlarging, truing and finishing ring slots in pistons and like articles. The/method" primarily in forcing or rolling.

through the slots a sharp-edged disk the width of which is slightly greater than the original width of the slot so that the edges of the disk shear or scrape oil from the side walls of the slots a minute layer of metal, leaving the surface of the metal scraped or highly polished and the groove of uniform lln practice ll find.-

diameter throughout.

a piston can be ished at the same time by the use of a plurality of axially movable disks mounted on an arbor. j

in practicing my novel method, I employ disks with sharp edges having a shear-' ing' action so that they scrape or otherwise remove from the parallel surfaces of the groove a minute layer of metal. ll, find in actual practice that this results'in the production of a highly finished surface and renders the groove true and accurate in width throughout its length, thereby producing a surface or surfaces against which the corresponding surface or surfaces of the piston ring will seat and makea gas-tight oint.

pointed out and clearly defined in the claim at the close of this s ecification In the drawings, ig. 1 is a view of a ma.-

lhe invention will be fully understood chine for practising the novel method cinbodying my invention.

Fig. 2 is a section taken on line 2-2 of Fire 1. v

,Fig. 3 is a detail view showin the construction of onev oi the roller diss used in the finishing operation. Fig. at is a view on an-enlarged scale of the grooved. portion of the piston showing the sheet on the piston'ot the finishing method described herein.

--Reterring now to the drawings, atll is shown a piston having three grooves, a, b and 0. These grooves are formed by ordinary methods and machined. Thereafter, the piston is supported on an arbor LIB-which can be rotated by a pulley l3. lln a suit the arbor. Each of the disks, as shown in Figure 3, has flat end faces at and e, and a smooth cylindrical peripheral surface f makingsharp peripheral edges 9 and ii... The

thickness of the disk is slightly greater than the width of the groove in which it is to be used. .lln practice ll find that it is well to make the disk .004.- or .005 of an inch thicker than the width of the groove so that the shaving or scraping which will be removed will be from .002 to 002% of an inch in thickn.

Illo finish the walls of the grooves a, l), and o in the piston, disks are moved upto the piston on the slide 20 on which the station ary arbor 17 is mounted. The piston is then caused to revolve slowly and the slide 20 fed toward the axis of the piston so that the disks gradually enter the grooves and as the piston revolves the disks are rotated, removing progressively a minute portion 73 of the surface, shown in F igure 4, and leaving the walls in a highly polished condition and of uniform width. The shavings or scrapings are forced into the bottom of the groove and are so minute that they do not interfere with the operation of the disks.

While my invention in its broadest form contemplates the use of a single disk to finish the flat surface of a piston ring groove, in practice I employ as many disks as there are grooves, performing the operation on all of the grooves simultaneously in the manner shown. This is perfectly practicable, since the disks, if mounted to be slightly movable axially of the arbor on which they are mounted, adjust themselves to any variations in the relative-position of the grooves.

The method embodying my invention not only produces a better piston than has heretofore been produced, but does so without subjecting it to any undue strains, as is the case where an attempt is made to compress the metal of the walls otthe grooves.

In the ioregoing description of the disk employed, I have used the expression a sharp edge to designate the construction of the tool employed. By the phrase sharp edge, I intend to connote any edge which has the effect of cutting, i'. e. removing metal from the wall in distinction to one which by reason of its shape or character is incapable of doing so.

What I claim is:

The method of enlarging, truing and finishing the ring slot in a piston or the like article, which consists in passing through the slot a disk-shaped roller having a sharp edge,

the width of the roller being slightly greater than the original width of the slots.

In testimony whereof I aiiix my si GEORGE A. TA

ature.