US1283091A - Piston. - Google Patents

Description

ii sas .anivnic.

DAVID r. CRAWFORD, or PITTSBURGH, PENNSYLVANIA.

PISTON.

T0 all whom t may concern:

Be it knownthat l, DAviD F. CRAWFORD, a citizen of the United States, residing at Pittsburgh, vin the county of Allegheny and State of Pennsylvania, have invented certainnew and useful Improvements in Pistons, of which the following is a specification.

The invention relates to pistons and more particularly to that class of pistons used in steam llocomotive cylinders, and has for its principal objects the provision of a piston having the properties of uniform expansion and contraction without increasing thetendency to'weai` the cylinder; the provision of a steam locomotive piston that requires no tail rod for the preventioiifof gouging the cylinder walls; the provision of a ooi'nposite piston wherein the parts combining to make up the piston 'may be inexpensively made and readily assembled and taken apart; the provision of a piston wherein the wearing yface may' be replaced' when worn without necessitating the waste incident to the discarding of a whole piston and the expense incident to refitting a new pistonupon the piston rod; aiidfsuch other improvements as will hereinafter appear. One embodiment of the invention together with modiiications of certain details of construction are shown in the accompanying drawings, whereinv Figure lis a longitudinal section through the piston and a portion of the cylinder; Fig. 2 is an elevation of a locking ring used in the piston shown in Fig. 1; Fig. 3 is a longitudinal section of a portion of a piston showing a modified form of ring locking mechanism; Fig. 4 is a front elevation of a portion of the device shown in Fig. 3; and Figs. 5, 6, v7, 8 and '9 are longitudinal sections of a portion of a piston showing' modi.- fied vforms of ring retaining devices.

Referring to Fig. 1, the piston consists of a central body portion 1 formed of steel by a' rolling process, the body portion Vconsisting of a. hub portion 2 and a cylindrical face por- `tion `3. A piston rod 4 extends through the hub 2 and is secured thereto by means of the nut 5.

It has been found that where 'a piston made Jof harder material .than the cylinder wall isl used in locomotive service', it was necessary to provide. a tail rod which had a bearing in the front end of the cylinder and projected therethrough. Without the use of such tail rodthe cylinder wall was found to: be gouged and scoredby the piston due `Specicatioii of Letters Patent.

Patenten oct. 2e, isis.

Application flied January 9, 1915. seriai No. 1,313;

to the greater hardness of the piston and to prevent such scoring of the piston a wearing lln der is made. A l

It has been found thatv pistons made by a Arolling process are far superior to those der 9. The 'ringv6 is adapted to be slidonto the cylindricall face portion 3 of rthe center portion 1, and is retained by means of the forcing the locking ring 11 from thefgroove 6 is provided preferably made from similar material to thatof which the cylin-v y flange'lO and a split locking ring 11, Figs. 1V

and then sliding the wearing riiig6 from the face portion 3. y 1

The wearing ring 6 may be retained in a number of ways, some of which are dis closed in Figs. 3 to 9 inclusive. xR-eferring `V to Figs. 3 and 4, the ring 6 is retained by means of the flange 10 and a sectional ring 11 mounted in the groove 12. The ends of the'ring sections 11 are secured to thefcyliiidrical portion 3 by means of the bolts 13 which extend through holes in the ring sec- -tioiis 11 and the cylindrical portion 3. -The ring sections 11 engage the wearing ringo ina manner similar to the construction of Fig. 1.

1 Fig 5 discloses' acylindrical portion 3 of the piston, having thereon the wearing ring 6 retained by'ineans of a flange A10a and a flat ring 14 which is secured by studs 15 tothe-cylindrical facel portion 3a. The` ring 14 is slipped'over the studs 15 and abuts the wearing ring 6. The nuts 16 are screwed tight against the ring 14 and thereby secure the ring 14 firmly against the wearing ring 6.

Fig. 6 shows a wearing ring 61D mounted upon a cylindrical face portion 3b which is provided with a flange 10b. The wearing ring 6b is secured to the cylindriealface por? tion 3b by means of bolts 17, one of which is disclosed, which extend through the flange 10b and screw into thewearing ring. Longitudinal movement of thewearing ring is prevented in one direction by the flange 10" and inthe opposite direction by the bolts 17.

Fig. 7 shows another modified form,

wherein the wearing ring G is mounted upona c vlindrical face portion 3c which is provided with a flange 10C for holding the wearing ring against movement in one direction. Movement in the opposite direction is prevented by-means of a plurality of arcuate keys 18, one of which is disclosed, having enlarged inside edges 19 which are adapted to be inserted .in a series of undercut grooves 20.

In the construction shown in Fig. 8, the lwearing,ring'G is retained upon the cylindrical face portion 3d by means of' the flange 10d and a series yof machine screws 21, one` of which is shown, the screws extending through the face of the wearing ring 6l into the cylindrical face portion 3d.V The heads of the machine screws 21 are located in counter sunk holes 22 so that they are beneath the face of the wearing ring.

Another modied form of construction is shown in Fig. 9 wherein a pair of Wearing rings 22, each carrying a packing rm'g 23,V

are arranged on each side of a central flange 21 which is integral with the cylindrical vface portion 3e. Rivets 25, one of which is shown, extends through both of the wearing rings 22 and the flange 24, which .face andprovided With an annular flange,

a ring adapted to be slid longitudinally on the cylindrical face of the body portion and abut the flange, a peripheral groove in the cylindrical, face of the body portion and a detachable lock ring in the groove adapted to engage the end of the first ring to sei cure it to the body ortion.

2. A composite cylinder piston comprising a central body portion having a cylindrical face and provided with an annular flange, a ring adapted to be slid longitudinally on the cylindrical face of the body portion and abut* the flange, a peripheral groove in the cylindrical face of the body portion, a locking member in the groove adaptedA Ato engage the end of the ring to secure it to the body portion andv means for retaining the locking member in the groove.

vIn testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

DAVID F. CRA'WFORD. Witnesses: l

Ro'r. REILLY,

IV. S. CAREY.

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