US2509686A - Boom stop for load handling machines - Google Patents

Description

y 30, 1950 w. M. HUSTON 2,509,686

BOOM STOPFOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Shee'ts-Sheet l (Deacon 3nneutor MMM 1 M Gtkornegs May 30, 1950 w. M. HUSTON 2,509,686

BOOM STOP FOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Sheets-Sheet 2 Smoentor May 30, 1950 w. M. HUSTON 2,509,686

BOOM STOP FOR LOAD HANDLING MACHINES Filed July 5, 1945 4 Sheets-Sheet 3 ()OOOOSOOOOC) Snnentor Gttornegs May 30, 1950 w. M. HUSTON BOOM STOP FOR LOAD HANDLING MACHINES 4 Sheets-Sheet 4 INVENTOR. My 4. Mum

770R NE Y5 Filed July 5, 1945 -.iltillIIouIllliilllllllllI!InIIllIlllililililllllllilillll Patented May 30, 1950 BOOM. STOP, FDR LOAD HANDLING I MACHINES William M. Huston; Lima; 0hio- ,ApplicationJulyfi, 1945, .Serial'No. 603,378

(Cl=.:212e--59) 3- Claims. '1

This invention relates to load handling-equip- ,ment, and particularly to self-propelled load handling machines adapted to travel on crawler treads. Ihe invention is especially concerned with a machine having an extended boom ,mounted for upward and downward swinging movement, for instance, a crane.

With equipment of the character mentioned above, especially a. large size machine having a long boom, the boomhas such mass that under certain abnormal conditions (for instance, breakage of a sling when hoisting a heavy load) the boom may tendto over-travel orswing'beyond the upper limit ,of the normal operating range. It is a, primary object of the invention to provide .mechanism for limiting upward swinging movement .of the boom atthe upper end of the desiredrange of movement, which mechanism is of sturdy construction'an'dcapable of preventing over-travel of the boom under certain conditions, and tothereby avoid possible damage to the machine and minimize tendency for the machine to tilt rearwardly.

According to the structure provided by the invention, means are also provided for cushioning the motion of the boom in the upward direction adjacentthe upper limit of. the movement.

More particularly, the invention contemplates the employment of telescopically arranged members adapted to be extended and collapsed asthe boom swings, and acting in compression upon being collapsed to limit upward swinging movement of the boom, the ends of the telescopic ele- ,ments being associated, respectively, with the headofthe .gantryand with the boom at a point spaced appreciably from the foot end. thereof, advantageously near tothe center oimassof. the boom.

.How the foregoing together with other objects and advantages are attained willappear .more fully from the following descriptiomreferring to the accompanying drawings in which.---

Figure 1 is a side outline view of a crane with the boom stop mechanism of the present invention applied thereto, withthe boom swung downwardly to a substantially.horizontalposition, a portion thereof being brokenoutfortcompactness of the figure.

Figure 2 is a viewsim-ilar to Figure 1 but with theboom raised to an angle approximating 48 "from the horizontal, in which position ithextelescopic stop. members are partlyzcollapsed;

Figure. 3 is ,a viewsimilar to Figures 1 and 2 but illustrating the boomrat the upwardilimit of its pivotal. motion, with .the telescopic stop members completely collapsed.

Figure 4 isa plan. view,.on anenlargedsoale of the telescopic boom stops, with the telescoping parts thereof. positioned substantially in. accordance with the showing .inzFigureB.

2 Figure 5 is-a plan secti'onalview througnone of the telescopic' boom stop devices, with the partsthereof' completely telescoped, as in Figure 3, FigureE being on astillfurther enlarged scale. 'Tliisvi'ew has parts broken out for the sakeoi compactness;

Figure Gis: aview similar to Figure-'5 butxillus- 5 trati'ngthe telescoping parts extended.

Referring first to-Figuresl', 2 and 3," the rotating base *1 of the crane there" shown is mounted for swingmotion on: the crawler truckrstructure 8, 1 the truck being provided with crawlertreads diagrammatically i indicated at, 9, .by iwhich the machine is adaptedr't'orber propelled on'the ground.

The rotating basezl serves: to: mount" the nner-- :ating machinery, including the power plant, boom hoist drums, etc, all of which machinery- 11 is%housed*withine the cab l-0. In the 'particular machine-- illustrated, the rotatingbase also sup- .ports-the controlitowen M which is ofi'set toward r one-side! of the plane ofipivotal:mevementof the it boom.

The foot end: of the .boom t2 TiS pivoted at 113 tow the rotating-:basa-to provide for upwardand downwardtmovement thereof through a range .such. ,asdefined -bythe "positions.- indicated; .in Figmaese 1: and 3.. Front compression gantry legs 1 I :4 extend. .upwardly and L reanwardly from. points adjacent the pivot-:axis w-ior theboom, to sup- .portthegantry. headshafti l5... Rear tension.gan-

try legsw t6 extend. downwardly (from: the gantry .headshaf-tto be anchoredi to-the rotating. base.

Raising-and. loweringnot. theboom. is controlled by the boom hoistlcable I]. which is. adapted -,to bereevedoven sheaves I8 mounted on thel-gantny headshaft- 15.,(see Eigure.4).,fthe boomhoist cable ultimately being carried. down into the cabifor cooperationswithaboom hoist drum. The cable l.1is,.,also. associated withsheaves 18" carried by a. sling, l9: whlchlfisisunported. from the point of the boom'by means oflslingjcables 2U. Ordinarily aanumber .01111118 or cable I I are provided between sheavestlfB and I8.

accordance with the invention, the gantry shaft [5 carries. pairs of upwardly projecting plates 2l', which are apertured' toward their upper .ends to receive pivot trunnions 22 projecting in :axial alignment with" each other transversely ot sleeves 23, one such sleeve being 'monnteddn this mannenadj acent each end 'of thegantryshaft 15. Each sleeve cooperates with i an assembly of telescopic-boomstop members which are extended forwardly therefrom for attachment to the" boom,

was isrillustrated' in the drawings. Since. the two assemblies oftelescopic :boom stopmembers are of the: same construction, only" oneneedfibedascribed.

Thea assemblydsi best shown; inliigures' 5; and-6 and? includes: an: 10111383111081". tubular member 24 having a rear end ,capJwZSsseI'Ving-mas:a stopwhen cooperating stop parts.

the cap abuts the rear end of sleeve 23 upon extension of the assembly. Tubular member 24 extends through and beyond sleeve 23 and is provided with an annular abutment 26 adapted to abut the forward end of sleeve 23 upon collapsing of the assembly when the boom swings upwardly. A second tubular member 21 extends into the forward end of member 24, the tube 21 having an annular abutment 28 which, upon collapsing of the telescopic assembly, is adapted to abut the fitting 29, which latter is secured to the forward end of the outermost tube 24. The tube 21 is restrained from being drawn completely out of tube 24 by an abutment sleeve 30 of diameter such as to engage the fitting 29. Sleeve 30, together with another sleeve indicated-at 30a, serve to guide the telescopic movement of tube 21 in tube 24.

A third or innermost tube 8! extends into the forward end of tube 21, this third tube having a 'forked terminal fitting 32 pivotall connected with the apertured ear 33, which is welded or otherwise secured to the structure of the boom (see Figure 4). The terminal fitting 32 also serves as an abutment to restrict movement of tube 3| into tube 21, the fitting being arranged to engage the end of the hollow cap 34 on the forward end of tube 21. A sleeve abutment 35 on tube 3| cooperates with the hollow cap 34 in preventing movement of tube 3| completely out of tube 21. Another sleeve 35a cooperates with sleeve 35 to guide the telescopic movement of tube 3| in tube 27.

Toward the rear end of the assembly (the left end as viewed in Figures and 6), a cushion device such as a compression spring 36 is arranged within the tube 24 to react between the inner end of tube 21 and the end of a spacer sleeve 3! disposed in the tube 24 just inside of the cap 25.

In the position of the parts illustrated in Figure 5, all of the elements of the assembly are collapsed or telescoped to the maximum possible extent and, from examination of this figure, it will be seen that the several abutments (26, 28 and 32) are all in engagement with the respective In this condition, the spring 36 is compressed although there still remains slight spacing between the turns of the spring, so that the compression forces will be carried through the several abutments referred to. The showing of Figure 5 corresponds to the position of the boom illustrated in Figure 3.

In Figure 6, the assembly of telescoping tubes is illustrated extended to the maximum possible degree, which corresponds to a boom position somewhat lower than that illustrated in Figure 1. In the preferred construction, the stop assemblies are arranged to have a degree ofextension suilicient to prevent, the parts from being placed under tension even when the boom is lowered to the maximum limit of the normal operating range.

Thus it is contemplated that downward movement of the boom shall normally be restrained only by the action of the boom hoist cable, but

-' and well braced reaction point for the boom stops when the latter act in compression to limit up- 1 Ward movement of the boom.

I claim:

1. In a load handling machine having a gantry and a boom, the latter being mounted for upward and downward swinging movement, mechanism for arresting upward swinging movement of the boom comprising a sleeve pivotally mounted on the gantry, a tubular member slidable in said sleeve, a compression member telescopically associated with the tubular member and connected with the boom, first stop means on the tubular member positioned to engage the sleeve, and second stop means on the compression member positioned to engage the tubular member, both of said stop means being operative in the upper range of swinging of the boom to limit telescopic movement of the compression member into the tubular member and sliding movement of the tubular member into the sleeve, whereby said members act in compression to limit the range of upward swinging of the boom.

2. In a load handling machine having a gantry and a boom, the latter being mounted for upward and downward swing movement, mechanism for arresting upward swinging movement of the boom comprising three telescopically associated members, one pivotally connected with the boom, one pivotally connected with the gantry and the third being telescopically intermediate and serving to interconnect the first two, stop means at the outer end of the internal member positioned to engage the outer end of the intermediate member upon telescoping of the internal member into the intermediate member when the boom moves upwardly, and stop means intermediate the ends of the intermediate member positioned to engage the free end of the external member upon telescoping of the intermediate member into the external mem her when the boom moves upwardly, whereby said external member acts in compression in limiting the upward swinging of the boom.

3. In a load handling machine having a gantry and a boom, the latter being mounted for upward and downward swinging movement, mechanism pivotally connected at one end to the boom and at the other to the gantry for arresting upward swinging movement of the boom, said mechanism comprising a plurality of telescopically associated members, stop means on one telescopic member positioned to engage the end of a second member into which it telescopes when the boom swings upwardly, and a yielding device connected with one of said members and adapted to react upon the other during the minor fraction of the upward movement of the boom which precedes engagement between said stop means and. said end, whereby said second member acts in compression in. positively limiting the range of upward swinging of the boom.

WILLIAM M. HUSTON.

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

UNITED STATES PATENTS Number Name Date 538,186 Widdows Apr. 23, 1895 546,088 Clancy et al Sept. 10, 1895 1,021,545 Messick Mar. 26, 1912 1,369,165 Cochran et a1 Feb. 22, 1921 1,563,860 Jacobson Dec. 1, 1925 1,658,873 Younkman et a1. Feb. 14, 1928 1,855,217 Berg Apr. 26, 1932 2,151,057 Suth Mar. 21, 1939 2,198,793 Schroeder Apr. 30, 19 10 2,318,491 Johnson May 2, 1943

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