US1416795A - Piston - Google Patents

Description

D. B. CRAWFORD.

FISTON.

AFE-LiCATlON .FILED AUG. 16. 1920.

1,416,795. Patened May 23, 1922.

2 SHEETS-SHEET l.

@md/@mq D., B. CRAWFORD.

PISTON.

APPLicATxoN FILED AUG. 16, 1920.

I mieres.

, engine.

Down is. CRAWFORD,

or cercado, rumors,

' l PISTON.

` j Specication of Letters Patent. I Pailgmtgqgd May 23',

vApplication filed August 16, 1920. Serial No. 403,784. I

T 0 all lwhom t may concern .i r

a'citiz'en .of the United States, residin vat Chicago, in the county of Cook and tate ofllllin'ois, have invented a new and useful. 'Improvement in Pistons, of which the following is a specification.

This inventionv has relation to an internal combustion engine, and refers particularly to a novel\ piston construction 4for such The primary object of myinvention is the -provision of an improved piston structure.,

More 'particularly 4my object is to introduce' resilient devices operating to increase the etliciency of the piston by urging the piston rings against the wall of thecylinder-- vTo this end my invention consists in the combinations and advantageous features hereinafter fully describedV and illustratedV in the accompanying drawings, 4of which:

Fig. 1 illustrates, in side elevation, a piston structure embodying the invention,

Fig. 2 is a plan view substantially in agreement with Fig. 1,A y

Fig. 3 is a fragmentary view, on a large scale, illustrating portions ofthe preceding figures,- Y

Fig. 4 shows the resilient' devic's removed from the piston, f Y

. Figs. 5 and 6 illustrate a modified form `of the inventionand Figs. 7 and 8 show further modifications the importance of which will`h/ereinafter appear. Referring in the rst instance to Figs. 1, 2-and 3,7 the numeral 1 denotes. a piston having a plurality of peripheral grooves 1, in which are seated a correspondlngnumber of piston rings 2. The latter may be of any well known constructlon and, of course the more perfectly the ends of the rings are joined together, the less also the leakagev pastv the joints of the rings. 'f ,Within the piston is placed av sleeve 3 providedmwith `a plurality -of radiallyA disposed sockets 3a,

Y in which are seated a corresponding number of springs 4., It is noticed that a corresponding number of perforations lb are provided in the grooves of the piston, and the sleeve 3 is so placed within thepiston that said'perforations register with the sockets 3a.y vSlidably mounted in each perforation is a plunger 5 urged lforward by thepressure of the springs 4, and a disc may conveniently be' placed between the spring and plunger, orv

hsaid. spring and plunger may beinade in one piece, if desired. The advantage of the separate disc and plunger 4is that less accuracy is required in positioning the sleevel relative to the perforations in the piston wall. .0n the other hand there is a distinct advantagein combining the parts, in that it yretains the plungers in place when ythepiston` ring is removed.

It is readilyfseen by anyone versed in the art that the springs t exert pressure against the inner periphery lofthe piston ringsfQ,

thereby urging the latter outwardl in orderv itselfcombined with the expansion of said ring causedl by the heat generated within the cylinder. lf the ring is too loose a decided waste of fuel ensues, if too tight the friction created operates to reduce the power output, besides` scoring and unduly wearing thewalls ofthe cylinder. While inthe common. type of piston rring great care must bey exercised to vselect the 'proper material, I wish it understoodthat, in the structure of my invention, the material best adapted for reducing frictionV between the ringand cylinder'wall may be adopted without pay- 9'0 ing. attention to the aforenamed conditions.

Thisis a very important feature of my invention.

The springs elaibeing` housed within the sockets of the sleeve 3,' are vprotectedfrom flame and dirt. It is, however, desirable' that some small opening be provided, such as the perforations 3", through which the 'splashing oil. may penetrate and thereby lubricate said springs.4 I have hereinbefore spoken of the sleeve as having one row of spring sockets operating up'on 'one piston ring,'in which case one sleeveis required for each ring employed, but I wish it understood that one common sleeve `may be used,` said sleeve having sockets for registration with the `whole group 'of piston rings, if'desired.

The l' sleeve structure hereinbefore describedis desirable on account ofthe easewith which it vmay be assembled and put ture for the reason that some pistons are `12. The spring sockets in this case, as best shown in Fig'. 6,- comprise a body portion 13 provided with diametrically opposite prongs 13a, which in turn are seated in perforations 10c of the piston. It is noticed that the ends l of said prongs are' riveted over in .order to retain the sockets firmly vin place, but, ot' course, ay spot Welding or similar operation may be resorted to for this" purpose. The

ysprings 14 and discs 1'5 remain as described, ,and I wish to point out, that the plunger and'di'sc also in this case may be combined into one piece, if preferred.

The structure of Fig. 8 corresponds in a general Way with the one just described.

.Specifically it is modified by eliminating the plunger element entirely. In this case the perforations 20 of the piston Wall are made large enough tol accommodate the body portion of the sockets 21, and the latter, as best shown in Fig. 8, are'made Witha {iange 21, which in turn is recessed into a seat in `the piston, in order that the face of'said socket may be flush with thel outer piston Wall. It is clearly shown how the disc 22 is urged by the spring 24: against the piston ring 23. Attention is called to a second series of sockets 25, said sockets positioned to register With the adjacent piston ring (not shown) and it is seen that the sockets 21 and the sockets 25 are placed in staggeredv relation, which is done in order vto retain the piston Wall as strong as possi- The devices hereinbefore describedillustrate plainly the scope of my invention, but the proportions and relations of the parts may, of course," be varied to suit conditions and in order to obtain the strongest and most )eiicient structure under the circumstances.

Also the number of spring sockets may be varied to suit individual conditions.

I claim: Y

. 1. The combination With the piston of an internal combustion engine and a piston ring, of means attachable to the piston for holding a plurality of spring-held plungers, said plungers confined Within the piston when the device is assembled and extending through the piston Wall in order to exert pressure against said pistonv ring.

2. The combination With a piston, provided With a series of radial perforations, and a piston ring'seated in said piston, of a sleeve carrying a series of spring-held plungers seatable in saidperforations, said sleeve insertable Within the piston when `the plungers are depressed, but'incapable of detachment when said plungers have entered the said piston perforations.

B. In the piston of an internal combustion engine, -a sleeve structure mounted Within said piston and having resilient members for urging the rings of the piston against the inner Wall of the engine cylinder. l

4:.A In the piston of an internal combustion engine, said piston provided with a series of radial perforations, the combination with the piston rings, of a sleeve fitted Within the piston, said sleeve perforatedto receive a corresponding series of plungers seated in said perforations,`resilient members urging said plungers against the inner periphery of said piston rings, and devices for maintaining said resilient members in position.

5.A In a piston for an internal combustion engine, a sleeve fitting the inner Wall of said piston and provided with series of staggered housings registering with perforations of the piston Wall, springs within said housings, plungers in said perforations and abutting the rings of the piston, and discs between said plungers and springs,

`said discs of larger diameter than the plungers in order to allow for inaccuracies of placing the parts.

In testimony whereof I have hereunto af iXed my signature.

DOLPH B. CRAWFORD.

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