US2426613A - Packing means for pistons - Google Patents

Description

Sgapt, 2, 1947. M. B. JACKSON PACKING IIEANS PISTONS Filed Aug. 30, 1 945 3 Sheets-Sheet l Sept. 2, 1947. M. B. JACKSON I PACKING MEANS FOR PISTONS Filed Aug. 30, 1945 3 Sheets-Sheet 2 IIIIIIIIIIII flue/afar dE-JMJO/C Jag.

P 1947- M. B, JACKSON PACKING 'HEANS FOR PISTONS Filed Afi so, 1945 3 Sheets-Sheet 3 B-MIOIC Patented. Sept. 2, 1947 omrso STATES PATENT orrica ltiaunsell 18. Jackson, Toronto, Ontario, Canada Application August 30, 1945, Serial No. 613,614

' The invention relates to improvements in packing means for pistons as described in the present specification and shown in the accompanying drawings that form a part of the same.

While many different methods have been employed for packing piston rings to prevent leakage of gas under pressure none of such means heretofore known have proved completely successful, due to the many problems involved. It is evident that the piston should be as light as possible in order to avoid sluggishness of action, and also that the piston be allowed sufficient freedom of movement to avoid undue friction.

The means most commonly used up to the present, despite the many methods tried, comprises a number of Ramsbottom spring compression rings carried by the piston and adapted to rub against the inner wall of the cylinder. Such rings, however, never entirely stop leakage, as is evidenced by the fact that there is always a considerable flow of gases out of the breather of an internal combustion engine, and, further, such multiplicity of rings causes great friction. In fact, tests show that at least one half of the total friction loss in an internal combustion engine so equipped is caused by the rings.

The present invention comprises a number of non-split rigid rings arranged in contiguous relation within a counterbore in the cylinder wall surrounding the piston and each, independently of the other, spring pressed from a different direction to eccentricity with respect to the vertical axis of the piston whereby the rings cooperate to provide an annular seal about the piston. The invention further provides for the use of lubricating and packing material under pressure to the ring assembly to provide a fluid seal between the internal surfaces of the rings and the external wall of the piston to prevent leakage and friction.

The main object of the invention is to provide packing means for a piston which will afford a very high degree of sealing efficiency combined with an extraordinarily low order of friction.

Another object of the invention is to maintain a low operational temperature for the sealing rings whereby to improve their efiiciency and insure longevity.

A further object of the invention is to provide for a maximum piston area through the elimination of rings on the outer urface of the piston.

A still further object'of the invention is to provide a packing assembly in which the path of leakage is a tortuous one which can readily be sealed by a suitable fluid, fed either continuously or inv termittently, as desired.

And generally the objects of the invention are to provide efiicient packing means for pistons, constructed of few and simple parts, which can be easily and quickly assembled, and which can be produced at small cost.

With the above and other objects in view the invention consists in the novel features of construction, arrangements and combinations of parts described in the present specification and more particularly pointed out in the claims for novelty following.

In describing the invention reference will be made to the accompanying drawings, in which:

Figure 1 is an elevation of an engine block with one cylinder hown in vertical section.

Figure 2 is a cross sectional view taken on the line 2-2 of Figure 1.

Figure 3 is an elevation of the spring locator extended.

Figure 4 is a plan View of the spring locator in its completed state.

Figure 5 is a'side elevation of the spring locator.

Figure 6 is a vertical sectional view through the piston, taken at right angles to the position shown in Figure 1. I

Figure 7 is a perspective view of one of the piston engaging springs.

Figure 8 is a vertical sectional view through a portion of Figure 1, showing a modified method of supplying leak preventing material to the ring assembly.

Figure 9 is a central vertical section through a modified form of construction.

Figure 10 is a cross sectional view taken on the line illit of Figure 9.

Figure ll is a cross sectional view taken on the line ll-i l of Figure 9.

Figure 12 is an enlarged sectional view through the ring housing and associated part of the cylinder.

Like numerals of reference indicate corresponding parts in the various figures.

Referring to the drawings, l indicates an engine block with which is incorporated a cylinder .2 having the usual liner 3 within which operates an annular ring housinglocated preferably be low the vertical centre of the cylinder and this counterbore is continuedthrough the lower end of the cylinder whereby to permit of the insertion of the rings, the springs adapted to act on said rings, and the spring locator which is described in detail hereinafter. That portion of the counterbore not occupied by the ring assembly is adapted to be. closed, after the ring assembly has been placed in position therein, by a sleeve ID adapted to a light push fit in the counterbore and having its inside diameter identical with that of the inside diameter of the upper part of the cylinder so as to provide a cylinder wall unbroken except to the extent of the depth of the ring housing. The sleeve l may be secured in position in any satisfactory manner but for purposes of illustration it is shown as being secured to the inner wall of the counterbored portion of the liner by welding through suitable openings I I previously provided through the liner.

The ring assembly comprises a plurality of rings I2,'! 3, M and I5, 01 like interior diameter and such diameter being slightly larger than the external diameter of the 'pist0n,-. adapted to be placed one over the other within the ring housing, a spring locator l6 adapted to encircle said rings, and a number of springs l1, l8, l9 and individual to the respective rings and held in position by the spring locator.

The spring locator It, consists of a thin, relatively wide annular band of slightlygreater depth than the overall depth of the assembled rings, and adapted to lie within the ring housing in engagement with the wall thereof and to beheld rigidly between the horizontal end wall'of the counterbore and the inner end of'the sleeve l0, said 10- cator being of slightly lesser length than the circumierential length of the wall of the counterbore so that when assembled the ends of the locator will be spaced apart to provide a gap 2| through which a sealing fluid may be fed-for the purpose of sealing the rings.

The spring locator is provided with a plurality of circumferentially extending slots 22, 23, 24 and 25, so arranged in stepped relation to one another that each slot will be opposed to a difierent ring, the slots 22 and located in the longitudinal centre of the locator being parallel with one another and being formed by cutting away the opposing edges of the band, so that the slot 22 will be opposed to .one outside ring and the slot 25 will be opposed to the other outside ring.

and the slots 23 and 24 being located interiorly v of the locator, with the slot 23' opposed to one inner ring and the slot 26 opposed to the other will stay in place.

axis of the liner 3 reversed, that is with the liner upside down of Figure 1, the locator I6 is placed within the counterbore against theinner end wall thereof. One of the springs (in the drawings spring ll) is'now entered in the slot 22 in the locator-as stated the springs are made slightly longer than the projections of the slots in which they are held so that once entered the springs One of'th e rings is now inserted in the locator and the spring pressed over by the ring until the ring can be pushed down flush on the bottom of the counterbore of the liner. Thespring will now be urging the ring inwardly. The spring I8 is now entered in the slot 23 and the process of inserting another ring and pressing the spring over by it until the ring bled in the counterbore of the liner, as shown in,

Figures 1 and 2. It will be noted that the rings l2, l3 and I I are urged in directions of 120 degrees to each other while thefourth ring, I5, is. urged in a direction parallel to the direction of urging of the ring l2. I0 is now entered in' the counterbore of the liner in abutting relation to the corresponding edge of the spring locator.

To insure an accurate spacing of the-rings between the bottom of the counterbore of the liner and the top of the cylinder extension whenthe cylinder extension is pushed right down in the counterbore, shims (not shown in the drawings) from .001 to .0015 in thickness are placed on the ring l5 between the top of the ring and the bottom of the cylinder extension. The cylinder .ex-

springs but with only slight possible movement in the direction of their ends.

It will thus be evident from the foregoing that the. mechanical parts of the present invention consists of rings assembled axially of a piston, and springs each enforced to contact and press on one of the rings, and a locator for the springs adapted to so hold them that the pressure exerted on the rings by the springs forces the rings inner ring. The slots 22, 2-3, 24 and 25 are spaced equidistant from 'one another circumferentially of the locator while the slots 22 and 25 are parallel with one another.

The springs I1, l8, l9 and 20 are adapted to be confined withinthe slots 22, 23, 24 and 25 respectively and each consists of a strip of spring metal of a width to fit'wlthin the confining slot but being slightly longer than "said slot so that when inserted in its slot with its ends confined by the ends of the slot it-will present a concaved surface to the outer edge surface of the ring a ainst which it bears. It will be evident that when once fitted into their retaining slots the is as follows: With the direction of the v r ic l into circumferentially'stepped contacting rela-.

tionship with the periphery of the piston, each ring contacting a portion of the periphery on one side thereof and therefore'being free of another portion of the periphery on the other side thereof. Experience shows that the portion contacted is slightly over degrees of the whole periphcry. That is that the contacting portions of the rings when the circumferential spacing of the rings is 120 degrees will have an appreciable overlap.

My method of fixing the direction of pressure on the rings by holding the springs freely so that they can press on the rings at one point and not tend to twist or turn them out of line is superior since I do not, as others have done, out or bore the rings to direct them, such cutting or boring making the rings unsymmetrical in section and therefore liable to warp or twist' out of flat, in

The sleeve, or cylinder,

With the present design the piston may be simplified and lightened since 'it does not have to carry rings, either compression or oil stopping.

In view of this the piston may be made as shown with an inside aluminum part to carry the wrist pin and act as a conduction member and with an outside steel cover, preferably hardened and ground to act as a wearing member. It is preferable to heat the steel part and shrinkit on the inside part so that when the outside part becomes heated it will not itself immediately swell, being in an initialstate of stress, and due to such state of stress will also restrain the inside part from swelling when it is heated.

I thus get the advantage of the aluminum part as regards thermal conductivity and lightness without the disadvantage of the high coefficient of heat expansion of aluminum and I get the advantage of the steel part as regards strength and wearing qualities.

It will be evident that gaseous leakage past the piston cannot be entirely stopped by my ring assembly only, there being two ways by which leakage can pass the piston.

First, leakage coming down axially between the piston and the liner and being stopped in its axial motion by the contacting portion of the top ring can, by changing its axial motion to circumferential motion round the ring through breaking through, whatever of the fiuid seal is forced out on one compression stroke being replaced before the next compression stroke. And it stops leakage of the second mentioned kind by filling the spaces between the rings and the I space behind them with constantly replaceable the space made by the arc of non-contact, by-

pass such contacting portion, and having done so can go down axially to the second ring, the contacting portion of which it can by-pass in the same Way, and so on down indefinitely.

Second, leakag'e coming down axially between the piston and the liner and being stopped as before by the contacting portion of the top ring can turn radially outwards from the piston and go between the upper surface of the top ring and thelower surface of the counterbore of the liner. It can then pass down behind the rings,

that is between the outer peripheries of the rings and the inner periphery of the locator and then turning radially'inwards towardsthe piston come out between the lower surface of the bottom ring and the upper surface of the cylinder extension and thence to the crank case. This type of leakage is greatly increased bythe fact that the tities of oil to the reciprocatingparts of an internal combustion engine is not practicable as the surplus oil .will seriously interfere with the operation of the engine, besides involving great extra expense for oil over and above that. necessary for lubrication.

It is my novel means for introducing this sealing oil, together with the novel arrangement of spring pressed rings, that enables me to entirely stop leakage without increasing materially, if at all, the amount of oil necessary for lubrication.

I attain this end by forcing sealing fluid, usually oil or thin grease, through a pipe 26 leading from the driven pump 21 to the interior of the ring housing at a point between the spaced ends of the locator l6, whereby such fluid will enter fiuid which not only prevents intermittent leakage ever getting through but forces the rings to act as if they were 'one piece with another and with the liner and cylinder extension as regards their axial dimension. Thus the rings cannot move up and down with regard to the liner and extension and thus cannot pump oil which, as is well known, is caused by motion of packing rings in their slots.

With some conditions one forcing of fluid into the spaces behind the rings as explained above lasts a long time. With some cases where intermittent injections only, are required I may employ in place of the pipe 26 from the pump 21, a compression cup, such as 28, shown in Figure 8, having a pipe 29 entering the ring housing whereby fiuid may be:supplied at will by simply screwing down the cup.

While in the embodiment of the invention described hereinbefore the rings are urged to eccentricity with respect to the vertical axis of the piston by springs located exteriorly of said rings it is of course apparent that springs located within the rings and exerting pressure on the interior peripheries thereof will also force the rings into eccentricity with respect to the piston. Figures 9, l0 and 11 show a modification of the invention, wherein the rings l2, l3, I4 and [5 are located in a housing formed in the outer periphery peripheries of the respective rings in circumwith the cylinder. wall.

ferentially stepped relation and forcing said rings outwardly I in different directions into contact In this embodiment of the invention, in so far as the provision of the ring housing is concerned, the piston comprises two sections 30 and 3| of like exterior diameter at their corresponding ends, adapted to be secured together in endwise spaced relation to one another by means of inwardly located flanges 32 and 33 interlocking with one another, with the fiange32 constituting the rear wall of the ring housing,

In this form of the invention the spring locator, the rings and the springs are assembled around the flange 32 prior to the assembling of the two piston sections 30 and 3! in a manner similar to that described hereinbefore in respect to the assembling of such elements in the first described embodiment of the invention, and the said piston sections are then connected togetherby forcing the collar, or flange, 33 of the section 3] inwardly within the flange 32 until the outwardly turned edge 34 of said flange 33 has reached its final position over the shoulder 35provided on the flange 32. I

In this showing of the invention the oil may be fed upwardly from the pump through a passage 36 which extends through the connecting rod into the interior of the wrist pin, and thence outwardly through openings in the ends of. the wrist pin into openings 31 in the piston section 30, which latter openingscommunicate withthe interior of the ring housing at points. circumferentially of the piston.

While I have illustrated and described the present preferred forms of construction for carrying out my invention, these are capable of variation and modification without departing from the. spirit of the invention. .1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

WhatI claim is:

1. A cylinder, a, piston operating within said cylinder, an annular ring housing, a plurality of rings positioned within said ring housing, a spring locator positioned within said ring housing, and a plurality of springs carried by'said spring locator and each urging one of said rings into eccentricity with respect to the vertical axis of said piston.

2. A cylinder, a piston operating within said cylinder, a ring housing in said cylinder and surrounding said piston, a plurality of rings assembled within said ring housing axially of said piston, and spring means individual to the respective rings urging said rings into circumferentially stepped contacting relationship with the periphery of said piston.

3. A cylinder, a piston operating within said cylinder, a ring housing in said cylinder and surroundin said piston, a plurality of rings assembled within said ring housing axially of said piston, and springs individual to the respective rings and positioned therebehind and each urging a ring inwardly into contact with the periphery of said piston whereby collectively 'said rings will provide overlapping peripheral contact with said piston.

4. A cylinder, a pistonoperating within said cylinder,-said cylinder being counterbored to provide a ring housing surrounding said piston, a plurality of rings assembled within the counterbore in the cylinder, and springs individual to the respective rings and positioned therebehind and each urging a ring inwardly into contact with the periphery of said piston whereby collectively said rings will provide overlapping peripheral contact with said piston.

-5. A cylinder, a piston operating within said cylinder, a ring housing in said cylinder surbled within said ring housing, springs individual to the respective rings and positioned therebehind and each urging a. ring inwardly .into contact with the periphery of said piston whereby collectively said rings will attain at least complete peripheral contact with said piston, and means for holding said springs against movement axially and circumferentially of said ring housing.

6. A cylinder, a piston operating within said rounding said piston, a plurality of rings assemrespective slots and urging said rings inwardly into contact with said piston.

7. Packing means for -piston s,,as set forth in claim 6, in which said springs are somewhat longer than the slots in which they are confined whereby said springs will present concaved surfaces to the peripheries of the said rings.

8. A cylinder, a piston operating within 'said cylinder, a ring housing surrounding said piston, a plurality of rings assembled within said ring housing axially of said piston, means individual to the respective rings urging said rings into circu'mferentially stepped contacting relationship with the periphery of said piston, and means vfor introducing a, sealing fluid into said ring housing to provide a seal between the inner peripheries of the --rings and the periphery of the piston, between the various rings, and between the rings and the walls of the ring housing.

9. A cylinder, a piston cylinder, said cylinder being counterbored to provide a ring housing surrounding said piston, a split with the periphery of said piston at diiferent points therearo'und, and means for delivering sealing fluid to the interior of said ring housing between the spaced ends of said band.

10. A cylinder, a piston operating within said cylinder, said cylinder having a, counterbore extending from a point intermediate of its length through the lower end of said cylinder, a sleeve fitting said counterbore and adapted to be secured therein with its top end spaced fromthe horizontal wall of the said counterbore whereby to provide an annular ring housing encircling said piston, a spring locator positioned within said ring housing, a plurality of rings positioned within said ring housing and encircled by said spring 10- cator, and spring carried by said spring locator and extending inwardly into contact with the respective rings at different points circumferentially of said rings whereby each said rings will be pressed into peripheral engagement with said piston at a different point circumferentially of said piston and whereby collectively said rings will have overlapping circumferential contact with said piston.

11. A cylinder, a piston operating within said cylinder, said cylinder having a counterbore extending from a point intermediate of its length through the lower end of said cylinder, a sleeve fitting said counterbore and adapted to be se cured therein in spaced relation to the inner end of said counterbore to provide an annular ring carried by said spring locator and extending insaid slots being also stepped circumferentially of said band, and springs confined Within the wardly into contact with the respective rings at difierent points circumferentially of said rings whereby each said rings will be pressed into contact with said piston at a-different point circumferentially of said piston and whereby collectively said rings will attain at least complete circumferential contact with said piston, ,a fluid pressure member, and a fiuid' delivery pipe leading from said fluid pressure member to the interior of said.

spring housing through the said opening in said spring locator.

operating within said 12. Packing means for pistons according to claim 11, in which said spring locator is of slightly greater vertical depth than the overall depth of the assembled rings.

13. Packing means for pistons according to claim 11, in which the slots in which thesprings adapted to act on the outermost two rings are confined are parallel to one another and are cut from opposite edges of said spring locator in substantially the longitudinal centre thereof and the slots in which the springs adapted to act on the inner rings are confined are located between the ends of the first mentioned slots and the corresponding ends 01 the spring locator.

14. A cylinder, a piston operating within said cylinder, a ring housing formed in the outer periphery of said piston, an annular band in said ring housing, a plurality of rings loosely encircling said band, and a plurality of springs carried by said band, each of said springs urging a ring from a different point into eccentricity with respect to the vertical axis of said piston.

15. A cylinder, a piston operating within said cylinder, a wrist pin, a connecting rod secured to said wrist pin, a ring housing formed in the outer surface of said piston, an annular band within said ring housing, a plurality of rings loosely encircling said band, a plurality of springs carried by said band, each of said springs urging one of'said rings into contact with the cylinder wall, an oil passage through said connecting rod and through said wrist pin, an-oil passage leading from the interior of said wrist pin to the interior of said ring housing, and an oil pump for forcing fluid through the aforesaid passages.

16. A cylinder, 5 piston operating within said cylinder, an annular ring housing, a'plurality of rings positioned within the said housing, individual means urging each of the said rings in a direction at right angles to the vertical axis, of the piston, and restraining means whereby the 10 i said individual urging means may be restrained from motion relatively to each other.

17. A cylinder, a piston operatin withinsaid cylinder, an annular housing, a plurality of plain annular discs positioned within said housing, the width of each disc being at least twice it thickness, individual springs urging each of the said discs in a direction at right angles to the Vertical axis of the piston, and a container for holding the said springs and restraining them from relative movement.

18. A cylinder, a piston operating within said cylinder, a wrist pin, a connecting rod secured .to said Wrist pin, a ring housing formed in the REFERENCES oI'rEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,218,132 Tuhey Mar. 6, 1917 1,871,820 Morton Aug. 16, 1932 334,037 Nash Jan, 12, 1886 1,597,706 Aldous Aug. 31, 1926 FOREIGN PATENTS Number Country Date Austria 1932

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