US1885290A - Piston - Google Patents

Description

1932. E. s. REILAND ET AL 1,885,290

PISTON Filed Sept. 6, 1929 Qwomto'o [772652 :5: fieizdrla FeY'GPJCZZeiZanZ Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE f ERNEST s. REILAND AND rn'rna M:REILA 1\TD, OF s1. PAUL, MINNESOTA, assIoNOns'ro UNIVERSAL PISTON COMPANY, OF s1. PAUL, MINNESOTA, A, CORPORATION OF MIN- NESOTA PIsToN Application filed September 6, 1929. Serial NO. 390,724. 7

Our invention relates to lightweight pistons particularly a piston made of aluminum alloyor of any other lightweight material of a similar nature wherein it is desired to pro vide a piston which will operate to maintain the compression rings in proper position and where the piston may act as the core to support the same and including a means for holding the piston centrally in the cylinder and against piston slap under any condition in the operation of the same.

A feature of the invention resides in a peculiar means for supporting the piston in the cylinder in a manner so that a more eflicient compression may be maintained particularly in high compression internal combustion engines, or in any internal combustion engine, all of which is accomplished by the means of supporting the piston within the cylinder.

Our invention further includes a means for holding the piston so that the major force of the explosion on one side of the same, as is prevalent in high'compressioninternal combustion engines, is overcome or prevented from affecting the pistonto cause it to be driven to one side Of the cylinder or to be tipped in the cylinder in its operation. This we accomplish with a particular means which is'a-daptable to compensatefor inequalities, wear and expansion and contraction. Our means of supporting the piston is such as to give a better compression in the cylinder and to largely overcome blow-by and thus prevent oil dilution which is so detrimental in internal combustion engines. 7

A furtherfeature of our invention resldes in means for supporting the piston inthe' cylinder with a large clearance, thus permitting the piston to be made without a split skirt or of a shell-like nature and yet with virtually a minimum of wall frictionowing to the nature of the supports for the piston. Our piston has a great deal, less wall friction because it has a lesser area engaging with the cylinder wall. In this means of supporting or holding the piston as will 'beomore fully hereinafter setforth, we maintain a cylindrical-like oil film about the skirt which lubricates the cylinder walls and rings of the piston 1n a very desirable manner. Thls O11 film is highly important as it not only lubricates the cylinder wall but it assists in maintaining a seal annularly or virtually cylindrical'ly about thepiston.

The features of our invention and objects,

together with the advantages and the particular construction and the means of carrying out the same will be more fully and clearly set forth. i

In the drawingiorming part of this specifitive construction of our piston.

In the drawing our piston A is illustrated with a thin wall at the skirt portion 10, whilethe head portion 11 is adapted to be formed 'with'the usual recesses 12 for the'piston compression rings. The-head 11 is also formed with an oil groove ring 13. Our piston A is designed to be made of aluminum Or-aluminum alloy 01' any lightweight material and is constructed of the solid type ratherthan of the split skirt type. This solid type structureprovides a cylindrical body from the head and through the skirt of the piston and :ow'ing tothe fact that aluminum or similar lightweightmaterial has a different cxpandingnature than that ofiron or steel, such as is'used in cylinder blocks and sleeves, it is essential that our piston A be made smaller in diameter than the diameter of the cylinder in which the piston is designed to operate; VVe-have found' th-at by particular supporting means such as B and C for the piston, that we successfullyoperate our piston to maint'aln the desired compression within the combustion chamber D, indicated diai grammatically bythe dotted outline, with the body or skirt of our piston from eight to fifteen thousandths smaller than the di ameter of the cylinder which is indicated diagrammatically by the dotted lines in Fig ure 1. In fact, our piston may have a greater clearance than even fifteen thousandths, if it is desired, and yet have no appreciable loss of compression owing to the structure of our piston supporting means 13 and C.

A further important feature of the supporting of our piston A which is designed to be made of lightweight material is in the fact that it may be made sufiiciently small in diameter to prevent the piston from engaging with the wall of the cylinder and in maintaining a cylindrical-like film .of oil between the piston supports B and C virtually at all times during the running of the piston and we have found that this struetureprovides a piston which may be placed in an internal combustion engine and the engine may be immediately run at any speed without injury to the pistons or the cylinder walls. This is an extremely valuable and important feature of our piston because it permits the use of our pistons in automobiles and instead of the driver being cautioned not to drive over a certain speed until the motor is run in, we have found that virtually no harm or damage can be done to either the pistons or the cylinders no matter at what speed the automobile is driven. The lubricating by the main tained cylindrical film of oil not only accomplishes the advantages of lubrication for the cylinder walls but also to the rings and to assist in maintaining a flexible sealing medium about the skirt spaced away from the head in such a manner as not to be infiuenced by the carbon formation in the combustion chamber D.

The supporting means B and C are of the same general structure excepting as to certain reversal of parts as will be set forth. In the support B we provide a bearing ring 14L which is formed with beveled surfaces 15 and 16 on either side of the same, the degree of bevel being varied to the desired extent. The bearing ring 14 is adapted to be supported against a beveled surface 17 formed in the head of the piston and with a portion of the arcuated inner surface 18 of thering 14bearing against the oomplemental arcuated shoulder 19 formed in the recess in the piston head which receives the ring 14;. The shoulder 19 extends in an arcuated formation for a certain distance within the recess which receives the ring 1 1 while the remainder of the recess is cut away as indicated in Figure 2 and also in Figure 1, so as to form a space 20 back of the ring 14 for a distance greater than the semi-circumference of the ring 14.

The ring 14 is made preferably of a cylinder wall diameter, that is, the outer bearing surface 22 of the same is of a cylinder wall diameter, and the ring 14: is held in position by a con'ipensating spring ring 23 which is formed with a beveled surface adapted to engage against the beveled surface 16 of the ring 14;.

To further assist the compensating ring 23 in supporting the ring ll in the desired position and to maintain the piston A properly positioned within the cylinder of the internal combustion engine, we provide one or more coil springs 2 1 which are positioned in suit- 'able recesses 25 in a manner U0 bear against the compensating ring 23. However, those coil springs 24: do not bear against the bearing ring 14 but against the inner surface of the compensating ring 23. The spring members 2 1 are positioned oppositely to the shoulder 19. This is an important structure of our piston A and it will be noted that this structure holds the ringl so that the back of the ring 1 1 will engage against the shoulder 19 and when explosive force from the combus tion chamber is exhausted against the head of the piston as indicated by the arrow 26 in Figure 1, the piston is estopped from rotating on its pivot point 27 (the wrist pin) and thus the piston cannot slap at the head.

It has been stated that the parts of the support C are reversed as to the same parts of the support B, however, the support C is of the same nature as the support B and the bearin ring 14 of the same is adapted to be supported by the arctated shoulder 19 back of the ring 1 1. These parts in the support C function. exactly the same as the parts of the support B and the support C is provided with springs 24 held in the recesses 25. It will be noted that the, shoulders 19 and 19 are positioned virtually diametrically opposite each other as are also the springs 24 and 2 1. This structure provides a particular function in the supporting of our piston A. o have stated that the force of the explosion in the combustion chamber D at a point near the arrow 26 would not carry the head of the piston 11 over against the wal of the cylinder and cause the same to slap and to assist in accomplishing this result in preventing the piston from rotating on the pivot point 27 (wrist pin) the shoulder 19' is positioned opposite the shoulder 19. Thus the shoulder 19 in the skirt 10 of the piston holds the skirt of the piston against movement toward the wall adjacent the shredder 19 in the direction of the arrow 28, Figure 1. The spring rings 23 and 23 which are the compensating rings of the two supports B and C for our piston A together with the spring means 2 1 and 24 compensate for any wear or inequalities in the parts and mainta in a sealed or tight fit between the beveled surfaces 15 and 16 of the bearing rings 14- and 14:. In this manner we provide a means of supporting the piston A centrally within the cylinder, yet with sufficient flexibility for wear and expansion and contraction and at the same time provide a means for maintaining the desired compression within. the combustion chamber so that in an internal combustion engine Where several cylinders are employed the combustion may be maintainedvirtually uniform within all of the cylinders. The beveled joints between the rings of the supports B and C and the piston assist in forming a sealing joint together with the oil film between the bearings B and C which is of a cylindrical nature so as to accomplish the results hereinbefore set forth and permit the piston A to be run at high speed without injury thereto or to the coils of the cylinder in which the piston is operating. i r

The grooves 12 support the ordinary compression rings and these rings assist in holding the compression and also in keeping the bearings B and C clean of-carbon formation,

thus facilitating the free and proper opera-- tion of the bearings B and G to maintain the piston freely operable inthe cylinder.

In Figure 4 we have illustrated a series of coil springs 30, 31, 32', 33, 34: and 35 which function similarly to the coil springs 2 by reason of the fact that these springs operate against the compensating ring 23. The springs 33 and 34 are positioned opposite to the shoulder 19, in this figure and these springs 33 and 34 are compressed greater than the remaining springs 30, 31, 32 and 35, to provide a greater pressure on that side of the compensating ring 23 than on the other side.

Obviously, it is not essential that the pistons be equipped with the coil springs 24 as the compensating sprin ring 23 may operate to perform the desired function in holding the bearing ring in its proper operating position. While it may be preferred to use the coil springs in some cases, we do not desire to be limited to their use because we know that our compensating bearin g rings'for our piston will operate to support the same'with or without these coil springs. The features of preventing the rotation of the piston readily carried out by our piston supporting means in the cylinder and thus we overcome side swiping of the piston or piston clearance slap in the operation of the same.

It will be apparent that our piston A may be operated in anycylinder of an internal combustion engine, either where the same is of a high compressiontype with the combustion chamber enlarged to one side of the piston, as illustrated diagrammatically in-dotted outline in Figure 1, or with the combustion chamber arranged centrally above the piston. I

The operation ofour piston has been set forth and includes the supporting of the lightweight piston by the supporting means which compensate for expansion and contraction and which are designed with stop means onopposite sides of the piston whicheliminates rotation of the piston on its pivot 27*- impossible to secure'a piston slap and at no time does the piston body engage the wall of the cylinder; Thus we overcome the detrimental side thrusting'eifect of the connecting rod at the wrist pin and owingto the rotary movement of the bearing rings 14; in their operation which we have observed in the'operation of our piston, we believe that wemaintain the wear of the cylinder round. instead of elliptical, therebyaccomplishing a very'desirable result. 1

In accordance with the patent statutes we have described the principal features and construction of our piston and we have ondeavored to represent the best embodiment thereof, setting forth some of the uses of the same, nevertheless, other features and ad vantages will be apparent as Well as other uses or forms of construction within the scope of the following claims.

1 We claim:

.1. A piston including, a body portion, a wrist pin connection therein, bearing means for said'body portion on either side of said wrist pin connection, said bearing means including a bearing ring, a spring compensat-v ing ring,: and a shoulder back of and con tacting with said bearing ring formed in said piston.

2. A piston support including, a bearing ring, a spring compensating ring adapted to hold said-bearing ring in contact with said;

piston. and the Walls of the cylinder, and an arcuate'd shoulder formed in said piston back of said bearing ring against which said hearing ring is adapted to engage to space said piston away from the Wall ofsaid cylinder on one side of said piston.

3. A I piston including, a body portion, a head portion, a skirt portion, a wrist pin connection in the body portion, supporting means on either side of saidwrist pin connection including a bearing ring,.a spring compensatingring, a shoulder back of said hearing ring on. one sideof said piston, and a space back of said bearing ring on the other side thereof, the shoulder of one of said supporting means being positioned diametrically opposite to the shoulderof said supporting means positioned on eitherside of said Wrist pin connection preventing rotation of the piston about the wrist pin connection in its oporation.

4. A piston formed of aluminum and alloy comprising, a body portion having an undivided skirt, a wrist pin connection, bearing means on either side of said Wrist pin connection having the parts of each of said bearing means reversed as to position, each bearing means including a bearing ring adapted to engage the cylinder wall, a beveled surface to engage the piston, a compensating spring ring, con'iplemental engaging beveled surfaces on said compensating ring and said bearing ring, a shoulder back of said bearing ring on one side and adapted to engage the same formed in said piston, and an open space on the other side, thereby providing oppositely disposed shoulders in said piston to permit the bearing ring to form a SlIiiuCGl between the cylinder wall and the piston to space the piston away from the wall of the cylinder.

5. A piston including, a body portion made of lightweight material, said body portion having means for supporting the compression rings, bearing compensating ring means supported by said body portion having shoulder means to )I'QVOIlt the rocking of the piston in its operation, means for spacing a greater portion of the bearing ring from said body and means for spacing the piston away from the wall of the cylinder so that at no time does the piston touch the walls of the cylinder.

6. A piston including, a body portion adapted to form the core to support the compression rings in a cylinder, wrist gin connection means in said piston, compensating bearing rings positioned on either side of said wrist pin and shoulder means formed in said piston back of said compensating bearing rings, positioned diametrically opposite the axis of the wrist pin connection, whereby the piston is supported against rotation on the wrist pin connection.

7. A piston including, a body portion adapted to support in the head the compression rings, a wrist pin connection in said piston, bearing rings positioned on either side of the wrist pin connection adapted to space the piston from the wall of the cylinder, compensating means associated with said bearing ring to compensate for the expansion and contraction of the piston and the wear of said bearing rings and shoulder means cooperating With said bearing rings and piston and positioned diametrically opposite the pivotal axis of the wrist pin connection to prevent rotation of the piston on the axis of the wrist pin connection.

8. A piston including, a body portion having ring grooves for the compression rings, a wrist pin connection for the connecting rod, bearing rings positioned on either side of said wrist pin connection and supported by said piston, a shoulder back of each of said bearing rings on one side of said piston and a space back of said bearing rings on the other side of said piston, a resilient compensating ring co-aeting with said bearing ring to hold the bearing ring in operative posi-- tion and resilient means engageable with said compensating ring on the side of the piston opposite to said shoulder means.

9. A piston including, a body portion, a head for receiving the compression rin s, a wrist pin connection in said body portion, a bearing ring positioned on either side of said wrist pin connection adapted'to support said piston in a cylinder, an arcuated shoulder portion formed to cooperate between the backof said bearing ring and said body of said piston on one side of said piston and an arcuated open groove back of the remaining portion of said bearing ring and piston.

10. in apiston provided with bearing ring grooves above and below the wrist pin axis thereof, a shoulder formed on the wall of each of said grooves, said shoulders being arranged on diametrically opposite sides of the piston, one in each of the respective grooves, bearing rings in said grooves having limited portions thereof in contact with. said shoulders, and means also carried in said grooves retaining said rings in contact with said shoulders and in contact with the walls of a cylinder when the piston is inserted in the latter.

11. In a piston provided with a bearing ring groove having an arcuate shoulder formed therein on one side of the wrist pin axis, a bearing ring engaging said shoulder, a compensating ring and means for exerting a preponderance of radial pressure on said compensating ring to seat said bearing ring on said shoulder and hold the same in contact with a cylinder wall.

12. In a piston provided with a bearing ring groove having an arcuate shoulder formed therein. on one side of the wrist pin axis, a bearing ring engaging said shoulder, a compensating ring and means for exerting a preponderance of radial pressure on said compensating ring at a point diametrically opposite said shoulder to seat said bearing ring on said shoulder and hold the same in contact with a cylinder wall. v

13. In a piston provided with a bearing ring groove having an arcuate shoulder formed therein on one side of the wrist pin axis, a bearing ring engaging said shoulder, a compensating ring in contact with said hearing ring, the contacting faces of said bearing and compensating rings being evelled on the same angle, and means for exerting preponderance of radial pressure on said compensating ring to said bearing ring on said shoulder and hold the same in contact with a cylinder Wall.

4. Seth;

14:. In a piston provided with a bearing ring groove having an arcuate shoulder formed therein on one side of the wrist pin axis, a bearing ring engaging said shoulder, a compensating ring incontact with said bearing ring, the contacting faces of said bearing and compensating rings being bevelled on the same angle, and means for exerting a preponderance of radial pressure on said compensating ring at a point diametrically opposite the said shoulder to seat said bearing ring on said shoulder and hold the same in contact with a 7 cylinder wall.

15. In a piston including top and skirt portions on opposite sides of the wrist pin axis,

said top and skirt portions being each formed with a bearing ring groove and each groove having a shoulder formed on a Wall thereof to one side of the wrist pin axis, said shoulders being arranged on diametrically opposite sides of the piston, a bearing ring in each groove engaging the respective shoulder I thereof, a compensating ring in each groove and means for exerting a preponderance of radial pressure on each compensating ring to seat the adjacent bearing ring on the adjacent shoulder and hold the same in contact with the cylinder wall.

16. In a piston including top and skirt portions on opposite sidesof the wrist pin axis,

said top and skirt portions being each formed with a bearing ring groove and each groove having a shoulder formed on a wall thereof to one slde of the wrist pin axis, sald shoulders being arranged on dlametrically opposite sides of the piston, a bearing ring in each groove engaging the respective shoulder thereof, a compensating ring in each groove, and means arranged at a point diametrically opposite the shoulder in each groove for exerting a preponderance of radial pressure on the compensating ring of the adjacent groove to seat the bearing ring thereof on the adjacent shoulder and hold the same in contact with the cylinder wall. 7

ERNEST S. REILAND. PETER M. REILAND.

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