Патент USA US2059728код для вставки
Nov; -3, 1936'. ' A lÉ». mick¢ PACKING CUP _ _2,059,728` ’ y _ FiledI 'May 29. 193s ` Fig@ 79 .9 \\\\\\ ~ _ _ Inventor". ¿BURNS DICK; ‘ - 2,059,128 `.Patented Nov. _3, l1936 UNITED STATES PATENT Aori-*ice rs(,:Zrißlrîï‘:azur'A y I Burns Dick, Ferguson, Mo., assigner to Wagner Electric Corporation, St. Louis, Mo., a corpo ration of Delaware Application May 29, 1933, Serial No. 573,367 ` 10 Claims. (Cl. 309-34) My invention relates to packing cups for pis the compressor piston packing cup being shown in Figure 4 of Loughead Patent No. 1,847,402 is tons and more particularly to improvements in sued March 1,1932, and an exampleof the motor packing cups used in fluid pressure producing s piston packing cup be ing shown in Figure 1 of systems, as for example, hydraulic braking sys pliver Patent No. 1,711,206 issued April 30, 1929. 5 tems, for preventing the escape of fluid under These rubber cups rely on the resiliency of the 5 'pressure past the piston. l rubber to retain the seal between the lip of the One of the objects of my invention is to pro cup and the cylinder wall. This resiliency, how duce a packing cup of iiexible material, the-lip ever, is. destroyed ' if overheatingA occurs, or if or edge of which will engage the wall of the cyl- _. the rubber is depreciated by the use of a poor 10 throughout its cir liquid, thereby resulting in an ineiiicient seal, » 10 inder with a uniform pressure cumference. - Another object of my invention is to so con- - struct a flexible packing cup that the radial pres sure between the lip and the cylinder will be 15 produced by an expansible means carried by the cup and acting at substantially right angles to the ' especially when the cups areëixli a non-operative position. The compressor cups -are also generally held 'against the head of the piston 3 by a retracting spring I4 bearing on its iiat central portion which also tends to draw the lip of the cup inwardly wall of the cup.` ‘ and thus reduce its pressure on the cylinder wall. Other objects of my invention are to produce Attempts have been made in the past' to use a packing cup of flexible material, as for exam springs to expand the lip of the cup and create ple, rubber, moulded cellulose compound, or light , -a uniform pressure between the lip of the cup metal, that will be simple in construction, eco and the cylinder wall, but these constructions impracticable because the nomical to manufacture, and _which will oper have been found to bedirect ate eiliciently for a long period of time.> outwardly radial di spring operates in a Still other objects will become apparent from ' rection and a very small increase or decrease> of 25 the following description of three embodiments the diameter in which they act, causes a, very of my invention takenin connection with the large increase or decrease in the radial pressure accompanying kdrawing in which Figure l is a of the'spring, thus producing unsatisfactory seal view, partly in cross section, of" the fluid parts of ing results under diffe rent operating conditions. a braking system equipped with two forms of In accordance with one embodiment of my in 30 30 cups embodying my invention; 'Figure 2 is a cross sectional view of the packing cup in the fluid compressor; Figure. 3 is a cross sectional view of ` one of the packing cups in the brake actuating motor; Figure 4 is «a cross sectional view of a metal packing cup embodying my invention; and Figure 5 is an enlarged view of a portion of the cup in Figure 4 showing .its relation to the cylin der wall. ' . vention, the rubber packing cup I2 for the com pressor is provided at its forward end withv an integral inwardly extending circumferential iiange I5 which forms, with the inner wall ofthe recess or groove I6. An cup, a circumferential I1 is interposed between expansible coil spring .the base of the cup and the groove IB and acts on the'flange I5 in a direction substantially parallel to the axis of the cup and at a distance from the peripheral wall of thel cup. The spring I‘I is of 40 vReferring to the drawing in detail, the nu meral I indicates the well known compressor of 'such resiliency and dimensions that it has a a hydraulic brake system which is provided with considerable working range, thus producing a a cylinder 2, a piston 3, and a reservoir t com substantially uniform axial force over a. con municating with -the cylinder ahead and at the ' siderable distance in its path of expansion. The rear of the piston in its retracted position by force produced by the spring upon the ilange I5 45 45 the passages 5 and 6. The cylinder of thecom the cup to be stretched and the lip thereof pressor is connected to the brake shoe actuating causes to be expanded outwardly, as shown by the dotted ‘ motors 1 by- a conduit 8 (one motor only being line of Figure 2. This radial expansion is a re shown). The motor comprises a cylinder 9 and suit- of the reaction caused by the spring I‘I` a pair of pistons I0 adapted to actuate the ends acting on the flange at a point spaced fromthe 50 the brake shoes II. Since the braking system line of support of the forward edge of the lip of '50 of must be as fluid-tight vas possiblathe pistons 3 the cup. The inner wall of the cup is tapered to andl >I0 are provided with packing cups .I2 and cause the 'extreme forward edge ofthe cup to I3 respectively. . , l' Y have the greatest radial expansion. As the ends In the brake systemsV now in use, the packing of the coiled spring are in contact with the iiange 65 cups are constructed of rubber, an example of 2 9,059,728 IB at all points, the outward expansion of the lip of the cup will be uniform, thus producing a uni form pressure between the cup and the cylinder wall. 'I'he large working range of the spring I1 also insures that pressure between the walls of the cup and cylinder will be maintained through out the wearing life of the cup. i coiled spring expanding in the axial direction of thecup and producing a force acting on the in wardly extending part of the cup 'and in a direc tion substantially parallel to tlîe cup axis.v 3. A packing cup having a flexible cylindrical wall carrying an inwardly extending part at its forward end, and a-n axially expansible coiled The inner surface of the base of the cup I2 is made convex and has mounted thereon a convex _spring acting in a direction substantially parallel 10 retainer I8 against which the end of the spring ing said inwardly extending part at a distance from the wall of the cup. Il abuts. The purpose of this construction is to prevent the rubber in the base of the cup from floating radially outwardly by the action of the spring Il and also to prevent any tension 15 in the inner peripheral wall of the cup which causes the inward4 deflection of the lip of the cup previously referred to. Referring to Figure 3, I have disclosed my in vention applied to a packing cup made from 20 semi-flexible moulded material, as forexample, -a cellulose compound. The cup I3 is shown as screwed to the head of the piston I Il and the lip portion provided with an inwardly extending `cir cumferential flange I 9. The intermediate wall 25 of the cup is of less thickness than the base por tion` to provide flexibility whereby the lip portion may be expanded outwardly. 'I'he flange I9 is also radially corrugated, as shown, to permit of this expansion. 'I'heexpansible spring 20 is 30 interposed between _the head of the piston and the flange I9 as shown. ,\ ' In assembling the structure, the lip of the cup is normally formed to snugly fit the cylinder and then the spring released after the cup -is 35 placed in the cylinder. The „radial expansion caused by the spring, and shown in dotted lines, need not be great under these circumstances in order to create sufficient sealing pressure be tween the lip and the cylinder wall. 40 ' In Figures 4 and 5, I have shown my inven tion' applied to a cup made from thin, flexible metal, as for example, brass. In this construc- ` to the axis of the cup and having one end engag 4. A packing cup having a flexible cylindrical wall provided with an inwardly extending cir cumferential flange at its forward edge, and means forcing the external forward edge of said 15 wall outwardly, said means comprising an ex pansible coiled spring engaging the base of the and the iiange, the force exerted by said s'pring being in a -direction substantially parallel to the axis of the cup and acting on the flange at 20 a distance from the wall of the cup. ' 5. A yieldable packing cup having a base por tion and a yieldable cylindrical wall, the forward end of said wall being provided with an integral inwardly extending flange forming a l circum 25 ferential groove, and an axially expansible coiled spring having one end engaging the base of the cup and the other end engaging the flange at said groove. ' 6. packing member having a flexible' wall an inwardly extending circumferential flange at ts orward end, said flange being so formed that its' internal diameter may be slightly in creased to thereby permit slight circumferential expansion of the forward end of the packing 35 member, anda coiled expansible spring axially positioned within said cylindrical wall and exert ing a force upon the flange in a direction sub stantially parallel to the axis of the cup whereby the forward edge of the wall will be forced radial 40 ly outwardly. 7. A packing member having a flexible wall and an inwardly extending circumferential flange nular flange ring 23 is soldered or otherwise se- ‘ 45 cured to the inner wall of the cup near the lip. at its forward end, said ñange vbeing provided 45 with radial corrugations which taper into a This ñange is corrugated, as shown, to permit smooth surface at its juncture with the wall, and the lip of the cup to be slightly expanded by the a coiled expansible spring 4lying within the cylin action of the expansible spring 24. A reinforce drical wall and exerting a force vupon said flange ment is provided in the bottom of the cup upon in a direction substantially parallel to the axis 50 which the spring seats. The lip of the cup is 50 _of the cup and at a distance from the wall. ground to a circumference to snugly fit the cylin _ 8. A packing member comprising a cup formed der prior to assembly and release of the spring. a flexible metal and ‘provided with aV ñared The cup is then placed in the cylinder and the ' _of open end, an inwardly extending flange secured to spring released, thus producing _a pressure be 55 tween the- edge of the lip and the wall in vthe _ the inner surface .of the open end ofthe cup, and an expansible spring engaging the bottom of the tion the lip 2l of the cup >22, is fla'red. An an manner shown in Figure 5. Having fully described my invention, vwhat I claim as new and desire to secure by Letters Patent of the United States is: 1 60 l. I'n fluid pressure apparatus, `.the combina- ' tion with a piston sealing cup of flexible material provided with aninwardly extending flange ad cup and the flange. , 9. In a fluid compressor provided with a cyl inder and a piston, a packing cup for the piston provided with an inwardly extending flange' at its forward end and araised surface on the bottom of ’o its interior, a coiled'spring linterposed between jacent -its lip, of means for increasing the contact the base of the cup and the flange, and a dished pressure of the lip of the cup on the cylinder bottom, -said retainer being provided with a pe 05 wall, said means comprising a coiled spring hav ing one end engaging the bottom of the cup and the other end engaging the inwardly extending flange on the cup adjacent its lip, and applying pressure to the flange in a direction which is at retainer engaging the raised surface of the cup ' ripheral groove forming a seat for the end of a 65 coil spring. 10. The combination of a piston and cylinder, a l packing cup for the piston provided with a convex 70 an 'angle to a plane perpendicular to the cup axis. ' surface on the bottom of its interior, and a con vex annular disc cooperating with the convex 70 2. In apparatus of the class described, a flexi cup surface, said disc -being provided with a pe- . ble packing cup provided with an inwardly ex ripheral groove for seating the end of a coil tending part'on its forward edge, and means for forcing the edge of said cup radially outwardly, 75 said means comprising an axially. expansible Spring. v « ' BURNS Droz. 76 .