US2512034A - Nonshimmying trolley - Google Patents

Description

June 20, 1950 R. T. MOORE 2,512,034

NONSHIMMYING TROLLEY Filed Dec. 23, 1944 2 Sheets-Sheet 1 w INVENTOR. )EAZPH T- Moo/i=5 A 7 TOP/V5 Y5 June 20, 1950 R. T. MOORE NONSHIMMYING TROLLEY 2 Sheets-Sheet 2 Filed Dec. 23, 1944 Patented June 20, 1950 UNI TE D ES 2,512,034;

NONSHIMMYING; TBO LEY BalphT. Moore, Lakewood; Ohio-,assignOrtox-Tlie. American MonoBail Companm (llevelandgflhina. a corporation of Ohio Application December 23, 1944; Serial'No; 5695447" 4, Claims. 1

This invention relates generally to monorail conveyor trolleys and particularly to a trolley which has a tendency to shimmy, that is, to move along a, rail with the wheels inclined at varying angles tothe edges-of the-rail or, in-other words, to travel along a zigzag path.

Overhead trolleys, of the type-in which a generally U-shaped yoke carries opposed, flanged wheels on axles at the open-ends of theyoke, have a tendency to shimmy while-traveling along-a monorail track. Such shimmying action is permitted by the fact that the distance between the flanges of the pair of wheels is greater thanthe distance between the edges of the track flanges on which the wheels run. When the plane of the axes of the wheels is perpendicular to the rail the trolley may shift laterally until-the flange of one wheel engages the side-of the rail. Such movement is provided for and'desired because-the ends of adjoining rails are not always of exactly the same width or in exact alignmentand such movement is necessary to permit free movement of the trolley from rail to rail.- The provision of spacefor such desired'latera movement permits the trolley to-shift angularly, that is, to move the plane of the wheel axes out of a line perpendicular totherail and thereby to incline the wheel flanges at an acuteangle tothe rail edges. When the wheels are so'inclined, they run along a path inclined to the rail edges-and eventually the leading part of the flange of one wheel or the trailing part of the flangeofthe other wheel contacts withthe adjacent railedge.

When such contact occurs the axes are shifted and the wheels run along a path-at anangleto the first path with eventualcontact' of wheel flange and rail edge which againshifts the axes. In this way the trolley traverses-a zigzag path along the rail with resultant wear on the rail edges and on the flanged partsofthe wheels and the formation of slivers' of metal which frequently break loose and fall. Such slivers'represent wear which should not occur and potential danger to workmen or Work therebeneath which shouldbe avoided. This oscillation of the trolley is commonly known as shimmy.

Altho this oscillating or shimmy problem has existed for many years and many attempts have been made to solve it, no one, to my knowledge, has solved it prior to my solution of it.

The present invention makes it possible to construct a trolley of the abovedescribed type which can shift laterally on: a railbut whichwill not oscillate or shimmy to a material extent even when lightly loaded and traveling at highspeeds 2-. and which canturn; readily toconformto curves in the rail.

The present invention will be betterunderstood by those skilled in the" art" from the following description and; the drawings which accompany .and formapart of this specification andin which Fig. 1 isa. diagrammatic plan view illustrating the. shimmyingaction" of trolleys running on a suspended: trackz;

Fig. 2. is:--a-fragmentaryside elevational view of a. paircof connectedi trolleys on: the track of an overhead: or suspended monorail. system;

Fig. 3-; is: an enlargedfragmentary end. elevational view, partly insection, takenon line 3-3 ofv Fig. 2-;

Fig. 4 is a verticalsectional'view takenon line 4-4 of Fig. 3;

Fig-5: is av view. similar to'Fig. 4 but showing a singleyoke and a. spreaden associated therewith;

Figs..6, 7 and 8am; respectively, top plan and side and :end elevationalviews of the shimmy suppressor-of Fig. 3;

Fig. 9 is a viewsimilan to Fig. 3but showing a modified form of shimmy. suppressor;

Fig.= 10.-is a sectional view, partly in elevation, takenon line a I 0- 0 .ofFig. 9;

Fig; I1 isa: View similar toFigs. 3 and 9 but showing another modified: form of suppressor; and,

Fig; I2iis$a sectional viewtakenon line |2-l2 of Fig. 11*.

In Fig; 1 the suspended-rail of a. monorail system is shownas consistingof a web! and flanges 2' extending outwardly therefrom and afiording surfaces: or tracks on which wheels-30f a trolley may. run; As. is. shown in Figs. 1 and 3, the wheels 3'. have flanges. which are farther apart than the distance between the opposite-edges of flanges 2. Accordingly, each pair of trolley wheels: 3.. may shift: laterally in either: direction relativet'orweb' tor the rail until a wheel flange engages. theadjacent edge of its. track. When the; plane of the axes ofthewh'eels is substantially:perpendicularto-theweb I of the rail, as is; shown; at the-left end: of Fig.1, the trolley-may shift; laterally in that-plane and thereby move freely; from one end of a: rail onto the abutting end of the" next. rail. even; though the overall width-of the-flanges of the two rails is not exactly the same-,or. the rail ends. are notin exact alignment. Such lateral shifting; when-thewheel axes are; perpendicular to. therail web, is desirable. Theother showingsrofrwheels:31in Fig. 1 illustratepositions the trolley wheelsmay. anddo assume.when-.a...trolley is moving along arail; The

clearance between the flanges of the wheels and the edges of the flanges of the rail permit the trolley to shift angularly so that the plane of the axes of the wheels is not perpendicular to the web of the rail; in other words, so that the wheels are inclined at varying acute angles to the edges of the flanges or tracks. When the trolley shifts so that the plane of its wheel axes is not perpendicularto the web of the rail, the wheels run at an angle to the edges of the rail flanges until the flange on the leading side of one wheel, the

wheel advanced by the shifting, engages the edge tends far enough below yoke 5 to have a spreader bar 18 mounted thereon to connect the yoke to of its track flange or until the flange on the trailing side of the other wheel engages the edge of its track flanges. Then the-iriction or impact 1 resulting from the engagement of one or both of these wheel flange portions with the track causes the trolley to shift in the opposite direction,

whereupon the foregoing operation is repeated.

This action is indicated on the right half of Fig. 1. This angular movement of the trolley wheels relative to the rail and the resultantoscillation of the yoke is commonly known as shimmying It may occur under a varietyof load and speed conditions but is perhaps most pronounced with high speeds and light loads. If the rate of such oscillation is slow it is not: objectionable. for it allows the rail to guide the wheels smoothly therealong and does not cause the wheels to wear the edges of the rails unduly or to apply impact forces to the rails. As the rate of oscillation increases, the rate of wear .of the rail and the strength of the impact forces deliveredto the rail increase and if the rate of. oscillation becomes sufliciently high it may even prevent movement of the trolley along the rail because of the resulting escapement action.

Figs. 2, 3 and 5 show a typical overhead suspended monorail trolley embodying the present invention. Each U-shaped yoke 5, which pref-' erably, but not necessarily, consists of two similarly shaped parts connected together by removable means such as bolts. and nuts,-has. a body portion 6 which extends beneath flanges 20f the rail and arms I which extend up pastthe flanges and carry axles 8 on which. wheels 3 are rotatably mounted. Theaxes of axles 8 are in substantial alignment. Each wheel .3 has a treadsurface I and a flange H. The space between the flanges H of a pair of wheels in a yoke isgreater than the overall distance between the free. edges of flanges 2 to permit the. lateral shifting of the trolley relative to the rail as above-mentioned. Two of yokes 5 are pivotally connected to a load bar l2. The bolt. 12a depending from the midportion of bar l2 may be attached to another bar (not shown) similarly connected to another bar 12. Such an assembly is known as an .8-wheel trolley.

Fig. 4 shows one form of such pivotal connection between a yoke and loadbar... In this figure the yoke 5 is shown as being provided with a recess open at'its top and bottom and having an inner bottom surface which is a portion of a spherical surface, .A thrust bearing 13 rests on the flat top of a washer I4, the lower surface of which is spherical to correspond to the inner bottom surfaceof the recess. The loadbar. I2 has a nut [5 preferably welded to its under surface and this nutrests on hearing 13.. .These several parts are held in assembled relation-by. bolt: [6 which is threaded into nut. 15 and-extends thru bearing I3, washer l4 and. yoke 5. Lubricant may be supplied .thru fitting I! to the recess in yoke 5 and to bearing. 13 and washer 14'- therein other apparatus such as a pushing unit. One

.side'of the head of bolt (6a is flattened to bear against a downward extension I9 of bar l8 to prevent turning of bolt 16a relative to yoke 5.

Means for suppressing shimmy is shown in Figs. 2 to 12 inclusive and having curved upper surfaces.

The form of shimmy suppressor shown in Figs. 2 to 8 inclusive comprises a spring 29 which has a wide body portion 2i attached to the top of load bar I2 or to nut 15a, as the case may be, and wings 22 which extend downwardly and bear on lugs 23 secured to the yoke 5. As will be better understood by reference to Fig. 8, each wing 22 is high in the center and is curved downwardly therefrom on each side to form fingers 24.

The lugs 23 engage against the under surface of the high part of wings 22 when the wheel axes are at right angles to the rail; and when there is any tendency for the yoke to shift so that the wheels are acuately inclined to the edges of the rail flanges 2, the lugs 23 will be forced against .fingers 24 of the suppressor and will deform them somewhat. The pressure of the spring and the resulting'friction will retard any shifting of the yoke relative to the rail.

- In the modification shown in Figs. 9 and 10 the shimmy suppressing means comprises a spring 30. This spring engages ledges 31 on the yoke and rests on the-top of nut 15a. The spring 36 is normally distorted by its engagement with nut 15a and ledges 3| so that it maintains its position on and exerts pressure against nut l5a at all times andthereby tends to retard relative rotation of the nut and yoke.

Another modified form of the suppressor is shown in Figs. 11 and 12 respectively where the yoke 5 is provided with opposed recesses iii! in which springs 41 are mounted to surround the stems 42 of shoes 43 whose inner surfaces are fragments of cylinders engaging the outer cylindrical surface of a nut l5a similar to that shown in Fig. 5 or nut 15 similar to that shown in Fig. 4 but somewhat longer in vertical length. The springs M serve to press shoes 43 against the nut and. thereby retard periodic pivoting action of the yoke relative to the nut. v The nut [5a of Fig. 11 is also similar to the nut 15a of Fig. 9 and is similarly attached; to the depending bolt (unnumbered) and, as is indicated in dotted lines in Fig. 11, the nut l5a is supported on roller bearings and a spherical washer like washer Id of Figs. 4 and 5 also shown in cross-section in Fig. 9.

It might be supposed that the anti-friction means between the trolley yokes and load bars or spreader bars, as shown in Figs. 4 and 5, would permit excessive shimmying action but such is not the case. I have discovered that shimmy occurs under certain conditions when these pivotal connections have high friction including poor bearings. The present invention, as embodied in the illustrated devices and comprisin antifriction pivotal connections between the yokes and the -load' bars or load-supporting members and the suppressors has been found to be capable of preventing substantially all shimmy action in unloaded or lightly loaded trolleys travelling at speeds of several hundred feet per minute and yet the trolleys move freely around curves when heavily loaded without any appreciable increase in resistance to the pivoting of the yokes relative to the load bars. The suppressors exert enough force to substantially prevent sudden changes in angularity of the wheels and rapidly reciprocating changes due to shimmy producing causes but do not exert so much force as to materially resist the turning efiect which is exerted by the wheels engaging a curved track. Thus the trolley is substantially free from shimmy but can follow curves quite readily.

Trolleys embodying the present invention have much greater lengths of service life than the prior trolleys and wear the rails to a much less extent. These advantages are traceable to the substantial absence of shimmy and to the presence of the low frictional bearing between the yoke and the load carrying member.

Having thus described my invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

1. A trolley for a suspended rail having opposed, outwardly extending flanges constituting tracks for trolley wheels, said trolley comprising a yoke member having opposed wheels to run on said tracks and flanges engageable with the sides of said tracks, a load carrying member rotatably connected to said yoke member and deformable means connected to one of said members and frictionally engaging and being initially deformed by the other of said members for impeding relative rotation of said members and sudden changes in angularity of the yoke member and wheels to said rail.

2. A trolley for a suspended rail having opposed, outwardly extending flanges constituting wheel tracks, said trolley comprising a yoke member having opposed wheels to run on said tracks and flanges engageable with the edges of said tracks, a load carrying member rotatably connected to said yoke member and initially stressed sheet metal spring means carried by the yoke member and frictionally engaging said load member for exerting pressure on the latter member and thereby retarding sudden changes in the angularity of the yoke member and wheels to said rail.

3. A trolley for a suspended rail having opposed, outwardly extending flanges constituting tracks for trolley wheels, said trolley-comprising a yoke member having opposed wheels to run on said tracks and flanges engageable with the edges of said tracks, a load carrying member rotatably connected to said yoke member and resilient means carried by said yoke member and initially stressed to exert pressure on said load carrying member to retard relative rotation of the said members and sudden changes in the angularity of the yoke member and wheels to said rail.

4. A trolley for a suspended rail having opposed, outwardly extending flanges constituting tracks for trolley wheels, said trolley comprising a, yoke member having opposed wheels to run on said tracks and flanges engageable with the edges of said tracks, a load carrying member, antifriction means between said members, said means including a part having a partial spherical surface, engageable with a correspondingly shaped surface on said yoke member, and initially tensioned means carried by one of said members and initially applying frictional pressure to the other of said members for retarding relative rotation of said members and sudden changes in angularity of the yoke member and wheels relative to said rail.

RALPH T. MOORE.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 1,195,850 Paige Aug. 22, 1916 1,528,372 Gouty Mar. 3, 1925 1,558,779 Bennington Oct. 27, 1925 1,740,415 Combs Dec. 17, 1929 1,775,429 Harris Sept. 9, 1930 1,889,112 Shoemaker Nov. 29, 1932 2,008,115 Taylor July 16, 1935 2,022,540 Dunlap Nov. 12, 1935 2,281,794 Peebles May 5, 1942

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