US 2746569 A
Description (OCR text may contain errors)
May 22, 1956 2,746,569
SNUBBING MECHANISM FOR GYRATING EXTRACTORS G. P. CASTNER 3 SheetsSheet 1 Filed NOV. 28, 195] IN VEN TOR. 65024: P Chan/1? firromrsrs PIE 5 May 22, 1956 G. P. CASTNER 2,746,569
SNUBBING MECHANISM FOR GYRATING EXTRACTORS Filed Nov. 28, 1951 I5 Sheets-Sheet 2 QMZMM/ y 1956 ca. P. CASTNER 2,746,569
SNUBBING MECHANISM FOR GYRATING EXTRACTORS Filed Nov. 28, 1951 3 Sheets-Sheet 3 FIGS INVENTOR. GEORGE E? Cur/vex BY W 4% Arm N578 SNUBBING MECHANISM FOR GYRATING EXTRACTORS George P. Castner, Webster City, Iowa, assignor, by mesne assignments, to Gamble-Skogmo, Inc., Minneapolis, Minn., a corporation of Delaware Application November 28, 1951, Serial No. 258,710
3 Claims. (Cl. 188-1) tion that machines of this general nature include a washing mechanism which is mounted for tilting, gyrating motion about a center pivotal support, with means for centering this assembly and for snubbing or frictionally damping the vibrations and gyrations thereof. In practice the clothes are washed in a tub by means of a suitable agitator and upon completion of the washing cycle the washing liquid is centrifugally extracted from the clothes by spinning the tub. Due to the fact that the load as represented by the wet clothes is almost never exactly evenly distributed about the spin axis, the spinning assembly is subject to very considerable eccentric vibrations due to this unbalanced load. This problem is well recognized in the industry and many attempts have been made to suppress the vibrations and absorb them before they are transmitted to the outer casing of the machine, which is, of course, very undesirable and which in many cases has made it necessary to bolt the machine to the-floor. In the machine of Patent No. 2,513,844 the gyrating assembly, or inner frame, is tiltably mounted at its lower end in a suitable bearing carried by the stationary outer frame of the machine and the inner assembly is yieldably centered by horizontally, radially arranged springs. In addition, the rotating receptacle or tub is provided with a heavy balancing ring, but it is further necessary to snub or frictionally damp the eccentric vibrations and gyrations in order to keep these motions within reasonable bounds.
.For this purpose in the earlier machine radiallyarranged snubber arms emanate from the inner gyrating assembly and at their outer ends carry snubber disks or friction shoes, between which are located plates which are secured to the stationary outer assembly. The respective snubber disks are then frictionally pressed into engagement with the plates by coil springs placed upon bolts piercing the snubbing assemblies, all as described in detail in the earlier patent. Such snubbing mechanism is-effective, but
the present invention improves upon this snubbingmechanism, both as to simplicity and more important as to efiectiveness in its function of snubbing and restraining the gyrations and vibrations.
In the previous snubbing mechanism it has been found difficult to equalize the effective spring tension upon the actual snubbing elements or disks and there is very little control over the horizontal travel of the snubbers as the '1 inner spin assembly gyrates. It will, of course, be realized that the centering springs will influence this travel, in
Y addition to which the flywheel effect of the balancing ring United States Patent I I v v 2,746,569 Patented May 22,1956
upon the tub will also have a bearing on this motion, but it is very desirable that the snubbing mechanism itself have a minimum travel in a radial or horizontal direction so that the mechanism will, in and of itself, operate to better advantage in restricting the gyrating motions of the inner assembly. It is accordingly the primary object of my invention to provide an improved snubbing mechanism which, while in many respects is similar to that disclosed in the mentioned patent, is so constructed and arranged that the effective spring tension upon the individual snubbers may be pre-set and maintained far more evenly and wherein the snubber springs are so arranged that the tension upon the coacting friction surfaces will be increased upon relative motion of these surfaces in any direction as the inner assembly gyrates. Thus it will be seen that the greater the amplitude of the gyrating movement the greater will be the effective braking tension of the snubber-springs, with the result that the travel will be minimized.
Another object of my present invention is to provide a snubbing mechanism which is simpler and less expensive to manufacture than that disclosed in the earlier patent.
These and other more detailed and specific objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in which- Fig. l is an elevational view, partially in vertical cross section, of a washing machine including an inner gyrating frame or washer assembly and outer stationary frame assembly and showing the application thereto of a snubbing mechanism according to my present invention.
Fig. 2 is an enlarged fragmentary horizontal sectional view taken substantially along the line 22 in Fig. 1 and showing in plan view one of the improved snubbing mechanisms.
Figs. 3 and 4 are respectively vertical sectional views along the lines 3-3 and 44 in Fig. 2.
Fig. 5 is a composite plan and side view of one of the parts of this snubbing mechanism.
Referring now more particularly and by reference characters to the drawing, the washing machine as shown in Fig. 1 thereof conventionally includes an outer stationary frame assembly, designated generally at A, and an inner, tiltably supported gyrating frame or washer assembly, designated generally at B. As noted hereinbefore this assembly is essentially the same as that disclosed in Patent No. 2,513,844, and as shown in Fig. l the outer stationary frame includes a base frame C enclosed in a suitable housing D and within the upper part of which is a liquid containing receptacle E. Disposed within the latter is a rotary receptacle or tub F which receivesthe clothes and washing liquid and the clothes are washed by means of the agitator G. The tub F and agitator G are carried by a generally upright and centrally located drive assembly and the latter is tiltably supported in a resilient bearing H held in a bearing cup I at the lower center portion of the base frame C. The assembly B may thus gyrate and tilt about its flexible support in the bearing H and normally the assembly is centered by means of a plurality of radially located centering springs, one of which appears at J and all of which are, of course, stretched between the relatively movable inner and outer frame assemblies. When spinning the tub F under unbalanced load conditions, the inner assembly may gyrate about its fulcrum at the bearing H, with the gyratory motion limited in part by the 'action of the centering springs J and in part by the flyends of the centering springs J are connected by eye-bolts M and as material to the disclosure of my present invention it is to be noted that this base ring provides inwardly directed, vertically spaced, horizontal flanges or brackets N and O which are located at some distance above the bearing H and below the stationary receptacle B. These brackets N and O, as they will be hereinafter referred to, are also, of course, spaced radially outward from the inner gyrating assembly F.
In accordance with my present invention a plurality of improved snubber or friction damper mechanisms are associated with the inner gyrating assembly B and the stationary brackets N and O and while there are three of such assemblies, each evenly circumferentially spaced from the next, I will here show and describe only one in detail since they are all identical in construction. Each such assembly then comprises a radially extending snubber arm 10, made up of flexible material such as spring steel, and secured at its inner end by bolts 11 to a suitable horizontal flange surface 12 forming part of the gyrating inner frame assembly B. The snubber arm projects from this point of rigid attachment to the gyrating assembly outward in overlapping and vertically spaced relation to the adjacent upper flange N and as seen in Fig. 2 the outer end portion of the snubber arm is considerably widened, as designated at 10 Secured in spaced relation to the underside of the paddle-like widened outer end of the arm 10 is a pair of rectangular snubber shoes 13, which are made of brake lining or similar material and are held in place by countersunk rivets 14 or other suitable fastening. The width of the outer end of the snubber arm is such, as compared to the corresponding dimension of the two snubber shoes 13, that the latter are spaced apart a considerable distance from the centerline of the arm or from a radius emanating from the spin axis of the gyrating assembly B, as clearly shown in Figs. 2 and 4. Interposed between the shoes 13 and the adjacent upper surface of the bracket N is a snubber plate 15 secured by bolts 16 or other suitable means to the bracket and this snubber plate thus forms a horizontal smooth surface coacting with the snubber shoes. As here shown the snubber plate 15 is generally rectangular in shape, with the corners cut away, and the length of the plate cross Wise of the snubber arm is such as to place the fastening bolt 16 well out to the opposite sides of the arm. The width of the snubber plate 15, as measured radially of the machine, is such as to provide for a considerable range of travel of the snubber shoes and as shown the snubber plate extends some distance inward from the upper bracket N for this reason.
The snubber shoes 13 are pulled down against the snubber plate 15 by a vertical, retractile coil, snubber spring 17 located between the upper and lower brackets N and O and having its lower end 18 hooked over the edge of the lower bracket and into an opening 19 provided therein for this purpose. The upper bracket N and overlying snubber plate 15 are then provided with large clearance openings 20 through which the upper end of the spring extends between the snubber shoes 13, and to receive the upper end of the spring the snubber arm 10 is provided along its centerline with a slot 21 spaced from the outer end 22 of the arm and aligned with a notch 23 opening through this end, as best seen in Fig. 2. The slot 21 and notch 23 thus provide an intervening web 24 and the upper hooked end 25 of the spring 17 projects up through the slot 21, crosses said web outwardly and then extends back down into the notch 23, as seen in Fig. 3. Actually this hooked end 25 of the spring does not directly engage the snubber arm at its center and the tension of the spring is placed upon a bridge or cross arm 26, disposed crosswise upon the arm and extending from one edge thereof to the other out over the snubber shoes 13. The bridge 26 is formed up from sheet material and is arcuate in cross section, as seen in Fig. 3, so as to resist bending stresses or distortion under the pull of the spring. At its center, furthermore, the bridge is formed with spaced depending lugs 27 of a width and spacing such as to fit down into the slot 21 and notch 23 while bridging the web 24. The opposite end portions of the bridge are then formed with laterally projecting flanges 28 to rest upon the upper surface of the snubber arm 10 and the lugs 27, by their engagement with opposite sides of the web 24, will hold the bridge in position crosswise of the arm as clearly shown. As viewed from the outer end of the arm, in a plane crosswise of the radial axis, the bridge 26 is crowned or arched at its center and the bridge thus serves to bring the tension of the spring 17 directly out over the snubber shoes 13 and acts to equally distribute the spring tension to and between the shoes.
In operation it will be understood that the tilting gyrations of the inner assembly B will, of necessity, cause the snubber shoes 13 to slide across the snubber plates 15, but the tension of the snubber springs and frictional action of the snubber shoes will yieldably resist this motion in order to snub and damp the gyrations, all as pointed out in the earlier patent. The snubber arms 10 must also, of course, be sufiiciently flexible to accommodate the tilting action of the inner gyrating assembly, while the openings 20 will be of such size as to permit the necessary travel of the snubber shoes without interference from the springs which project upward through said openings.
It is of extreme importance, in order that the snubbing mechanism have the desired damping effect upon the gymtions, that the movement of the snubber shoes 13 in any direction be immediately resisted by the tension of the snubber spring 17 and that such movement be accompanied by an immediate increase in the effective spring tension on the shoes. In the earlier snubbing mechanism hereinbefore referred to the snubber springs, since they were positioned upon bolts which held the snubbing disks together and traveled therewith, had only a constant spring tension on the friction surfaces, but in the present case, since the snubber springs 17 are stretched directly between the stationary lower bracket 0 and the superimposed movable snubber arm 10 and stand vertically when assembly B is on center, it is evident that motion of the snubber shoes in any direction will then tilt the springs and accordingly stretch them to immediately increase their effective tension on the shoes. Thus in the case of the three circumferentially spaced snubbing mechanisms, as contemplated by my present invention, it will be seen that all three mechanisms will continually operate to damp gyrations and vibrations in any direction and thus the mechanism will operate with utmost effectiveness for the desired purpose. It is, of course, important that the snubber springs be vertically positioned for this purpose since otherwise, While a motion in one direction might tend to stretch the spring and increase the tension, an opposite motion would have the opposite and undesirable effect of decreasing the tension. For example, if the springs were arranged diagonally they might also be utilized to some degree to center the gyrating assembly, but they would then lose much of their effectiveness in the snubbing phase of their operation.
In addition, the structure as herein disclosed is extremely simple and convenient to assemble during manufacture of the machine and the fact that short vertically positioned springs are thus used enables me, by the proper selection of springs of good quality, to pre-set the tension upon the individual snubbing mechanisms and to maintain this tension at an even ratio under all conditions of operation. The provision of the bridge 26 brings the spring tension out evenly over the individual snubber shoes 13 of each mechanism so that the maximum snubbing effect is obtained and the shoes will wear in evenly and have a long useful life.
It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:
1. In a clothes washing machine, an outer stationary frame, an inner gyratory frame and means mounting the same in said outer frame for gyration about a normal upright axis; snubbing mechanism for resisting such gyration of the inner frame, comprising a base ring secured to the outer frame and surrounding the inner frame and having an inwardly turned flange, a plurality of vertically flexible snubber arms annularly spaced within said ring and rigidly secured to the inner frame and extending outwardly over the said flange and each having snubber shoes on its underside, a snubbing plate secured to the flange under said snubber shoes and these plates and the flange having registering openings, retractile coil springs extending vertically loosely through said openings and means attaching the upper and lower ends of the springs respectively to the snubber arms and the stationary frame whereby the tension of the springs will pull the snubber shoes downward with increasing pressure into frictional contact with said plates upon horizontal displacement of said inner frame in any direction.
2. In a clothes washing machine, an outer stationary frame, an inner gyratory frame and means mounting the same in said outer frame for gyration about a normal upright axis; snubbing mechanism for resisting such gyration of the inner frame, comprising a base ring secured to the outer frame and surrounding the inner frame and having an inwardly turned flange, a plurality of vertically flexible snubber arms annularly spaced within said ring and rigidly secured to the inner frame and extending outwardly over the said flange and each having snubber shoes on its underside, a snubbing plate secured to the flange under said snubber shoes and these plates and the flange having registering openings, retractile coil springs extending vertically loosely through said openings and means attaching the lower ends of the springs to the stationary frame, and a bridge member attached to the upper end of each spring and extending at its ends oppositely over the snubber shoes to equally distribute the spring tension to both shoes on each snubber arm.
3. In a clothes washing machine, an outer stationary frame, an inner gyratory frame and means mounting the same in said outer frame for gyration about a normal upright axis; snubbing mechanism for resisting such gyration of the inner frame, comprising a base ring secured to the outer frame and surrounding the inner frame and having an inwardly turned flange, a plurality of vertically flexible snubber arms annularly spaced within said ring and rigidly secured to the inner frame and extending outwardly over the said flange and each having snubber shoes on its underside, a snubbing plate secured to the flange under said snubber shoes and these plates and the flange having registering openings, retractile coil springs extending vertically loosely through said openings and means attaching the lower ends of the springs to the stationary frame, a bridge member attached to the upper end of each spring and extending at its ends oppositely over the snubber shoes to equally distribute the spring tension to all the shoes on each snubber arm, the snubber arms being notched to clear the upper ends of the springs and the bridge members having lugs to fit into said notches to hold said members in proper relation to the snubber shoes.
References Cited in the file of this patent UNITED STATES PATENTS 781,732 MacFarlane Feb. 7, 1905 1,564,659 Xardell Dec. 8, 1925 1,763,682 Wallace June 17, 1930 1,772,602 Dunham Aug. 12, 1930 2,268,204 Dunham Dec. 30, 1941 2,396,105 Kirby Mar. 5, 1946 2,454,112 Woodson Nov. 16, 1948 2,513,844 Castner et al July 4, 1950 2,534,194 Emmert et al. Dec. 12, 1950 2,585,107 Geldhof Feb. 12, 1952 2,614,410 Kirby Oct. 21, 1952 FOREIGN PATENTS 475,199 Great Britain 1937 674,698 Germany Apr. 1939