US3032207A - Loading boom with adjustable extension arm - Google Patents

Description

S. S- M INTYRE LOADING BOOM WITH ADJUSTABLE EXTENSION ARM Filed Feb. 23, 1960 May 1, 1962 2 Sheets-Sheet 1 INVENTOR. 6101451 SJYINTYRE May 1, 1962 s. s. MCINTYRE 3,032,207

LOADING BOOM WITH ADJUSTABLE EXTENSION ARM Filed Feb. 23, 1960 2 Sheets-Sheet 2 U 1 A INVENTOR. 1|? m [1 43 6/0 YSM /HTYRE 7 90 Q- WI 3M I Mmd" HTToRnEYJ nited States Patent Ofiice 3,9323%? Patented May 1, 1962 3,032,207 LOADING BUOM WITH ADJUSTABLE EXTENSIQN ARM Sidney S. McIntyre, Sedro Woolley, Wash., assignor to The Humboldt Company, Seattle, Wash. Filed Feb. 23, 1960, Ser. No. 10,449 6 Claims. (Cl. 212-35) This invention relates to improvements in load lifting cranes of those kinds or types that are typified by the device of US. Patent #2,895,622, issued to A. E. Sundin on July 21, 1959; such a crane usually being mounted on a mobile vehicle and comprises a rigidly fixed, vertical standard which, at its upper end, mounts a boom for vertical and horizontal swinging and which boom, also, as a characterizing feature, is equipped at its outer end with an extension lever arm that may be swingingly adjusted in a vertical plane between positions of use, at which it is extended outwardly from the boom end and a position of rest, at which it is folded inwardly and extended along the top side of the boom.

It is the principal object of the present invention to provide improvements in the means associated with the boom for swinging the extension lever are between any of its extended positions and its back folded position of rest and for holding it at any position between its limits of swinging adjustment.

More specifically stated, the present invention resides in the utilization of leaf chain belts in conjunction with the piston rod of a hydraulic cylinder for making and holding the adjustments of the extension lever arm.

Further objects of the invention reside in the details of construction of parts, in their combination and in their mode of operation, as will hereinafter be described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a rear end elevator of an automotive truck on which a loading or load lifting crane, embodying the improvements of the present invention, has been mounted and showing the boom extension lever arm in its inwardly folded position of rest.

FIG. 2 is a side view of the boom with the extension lever arm adjusted to an extended position of use.

FIG. 3 is an enlarged sectional detail taken on line 3-13 in FIG. 1, showing the standard rotating gear and rac c.

FIG. 4 is an enlarged horizontal section, taken on line 4-4 in FIG. 3.

FIG. 5 is an enlarged sectional view taken through the hinge joint of the boom and its extension lever arm.

FIG. 6 is a vertical cross-section, taken on line 66 in FIG. 5.

FIG. 7 is a schematic showing of the valve and hydraulic devices for making adjustments of the jacks, boom and lever arm.

Referring more in detail to the drawings:

In FIG. 1, the present boom is shown as operatively mounted on a motorized truck comprising a chassis made up of longitudinally extending opposite side beams 1010 supported at the rear end of the vehicle by and upon a cross-axle 12 that is equipped at its ends with paired wheels 1313. Fixed upon the chassis, transversely thereof, and extended equally to opposite sides to points slightly beyond the line of the wheels 13 is a tubular housing 15 on and by which the boom is mounted, as will presently be explained. The cylindrical or tubular housing 15 is seated by and is fixedly secured in saddles 1515' which, in turn, are suitably bolted to the chassis beams Iii-10. At its opposite ends, the tubular housing 15 is closed by cover plates 1616 which mount vertically extending jacks 1717 thereon to be used as presently explained.

The present boom is mounted on the tubular housing 15 in the central longitudinal line of the truck. It comprises a tubular standard 19 which, at its upper end, mounts the present loading boom Ztl thereon. This boom is a metal fabrication, pivotally fixed at its inner end to the upper end portion of the standard by a horizontal hinge pin 21 for vertical swinging adjustment between its downwardly extended position of FIG. 1 and the upwardly extended position of FIG. 2. This boom is equipped at its outer end with an extension lever arm 22 which arm is mounted at its inner end by a pivot pin 23 for vertical swinging adjustment from a position of use, or horizontal extension, as in FIG. 2, to a position of non-use, as in FIG. 1 at which position it is folded back along the top side of the lowered boom.

It is to be observed in FIG. 5 that the inner end of the extension lever arm 22 is equipped with an upwardly 0&- set bearing portion 24 receiving the pin 23 whereby the extension lever is mounted and whereby, when this lever is folded back along the boom, as in FIG. 1, it will be permitted to lie back along the top side of the boom 20'. Both the boom 20 and extension lever arm 22 are of hollow construction as shown, and it is further to be noted that the bearing portion 24 is a part of a casting 25 that provides a cylindrically rounded outer surface for the arcuate chain guide rails 25x for seating the lever operating leaf chains as presently explained.

The vertical swinging of the boom 20 is under control of a hydraulic cylinder 30 that is pivoted at its inner end within the upper end portion of the standard 19, as at 31, to extend along and within the under portion of the boom. This cylinder 30 has an extendable and retractable piston rod 33 fixed pivotally at its outer end, by a pivot pin 34 to the medial portion of the boom 20. Fluid pressure medium is applied, as presently explained, to the inner end of the cylinder 30 to effect the upward vertical swinging adjustment of the boom.

The swinging adjustment of the extension lever arm 22 is under control of a hydraulic cylinder 36 that is contained within and extends along the boom. It is pivoted at its inner end to the boom by a pivot pin 37 and has an extendable piston rod 38 which at its outer end is attached as at 39 to the ends of paired leaf chains 40 which extend upwardly and about the chain guides and are fixed at their other ends, as at 42 in FIGS. 2 and 5, to the casting 25. When the lever arm 22 is in the position, relative to the boom 20 shown in FIG. 2, and it is desired to swing the lever arm upwardly and to its retracted position, the piston rod 38 is caused to be extended, and through the chains 4040 to effect this adjustment. This is possible with the boom positioned either as in FIG. 1 or as in FIG. 2.

It has been shown more particularly in FIGS. 2, 5 and 6, that dual chains 404tl are used and that the extension lever arm 22 as equipped with the chain guiding rail segments 25x provides progressively decreasing leverage for the upward swinging adjustment of the lever arm. The piston rod 38 as shown in FIG. 5, receives the dual chains 404tl along opposite sides thereof, as the rod is fully extended as in FIGS. 1 or 5.

At its outer end the lever arm 22 is equipped with suitable means, such as that represented at 55 in FIG. 2, for attachment thereto of load lifting chains or the like. This means 55 may be applied to arm 22 or, as here shown, to an extension 22' that is telescopically extendable from arm 22.

The tubular standard 19 which supports the boom 20 is rotatably mounted at its lower end on the housing 15 as shown in FIG. 4, for axial turning about a vertical post 60 that is fixed rigidly in the housing and extends upwardly therefrom. The standard is equipped with a ring gear 62, about its lower end, and this is enclosed by a housing 63.

v Supported horizontally and in intermeshing relationship with gear 62 is a rack bar 64 that is contained longitudinally within a hydraulic cylinder 65 as seen in FIGS. 7 and 3. At its ends, the rack bar is formed with pistons 66-66 that are reciprocally fitted in cylinder 65. Adjustment of the rack bar endwise in opposite directions operates to rotatably adjust the standard to swing the boom horizontally in opposite directions.

It has also been shown in FIGS. 1 and 3 that the cylinder 65 has been fixed upon and extends along the housing 15.

The hydraulic control system for the operation of the various movable parts is as shown schematically in FIG. 7. It is to be understood that the cylindrical housing 15 serves as a storage reservoir for a suitable fluid pressure medium. A pump 85 operates to continuously draw pressure medium from the reservoir through a supply line 86 and deliver it under pressure through a pipe line 87 to all valves of a control valve unit designated in its entirety at 88, for delivery, selectively, from the valves to various points of use. The valve unit mechanism 88 comprises five independently operable valves each receiving pressure medium from the pump 85 as indicated. These valves are designated, respectively, in FIG. 7, by reference characters a, b, c, d and e. Valves and d are double acting. The pipe line 87 serves all valves of the unit 88. Valve 0, is connected by pipe lines 90 and 91 with opposite ends of cylinder 65 and controls the horizontal swinging adjustments of the boom. Valves a and e are connected, respectively, to the jacks 17 and 17 by pipe lines 92 and 93 to give support to the vehicle chassis when support is needed. Valve b, connected by pipe line 95 with the lower end of cylinder 30, controls the vertical swinging of boom 20. Valve d which is double acting and is connected by lines 96 and 97 with opposite ends of cylinder 36 controls the action of this cylinder for its swinging adjustment and support of the extension lever arm 22.

If the boom and its extension lever are in the positions of FIG. 2, the boom may be lowered by adjustment of valve b for outflow of fiuid from the lower end of cylinder 30. With such lowering of the boom, the piston rod 38 of cylinder 36 can be extended under control of valve d to swing the arm 22 to its back folded position as in FIG. 1. Rotation of the standard to move the boom to either side of the vehicle is under control of valve 0. Valves a and e control the jacks 17-17 to level up the chassis or give support thereto.

It has been shown in FIG. 1, that the valve assembly 88 is mounted at one side of the vehicle and that the five valves a, b, c, d, and e are individually controlled by levers 98 that are fixed on corresponding cross-rods 99 which extend to opposite sides of the vehicle and each of which, at its opposite ends, has actuating levers 160 fixed thereto so that the control can be effected from either side of the machine.

If the lever arm 22 is in a position lying along the boom 20, as seen in FIG. 1, it can be manually pulled out to a position at which its weight will efiect its outward and downward swinging movement under control of valve d.

The hydraulic cylinder 36 and chains 40-40 are effective in lifting the lever arm 22 in a vertical arc from a substantially horizontal position as illustrated in FIG. 2 to a substantially vertical position where the center of gravity of the arm intersects a line perpendicular to the horizontal. The continued movement of the arm to overlie the boom may then be manually controlled with the boom lowered to the position illustrated in FIG. 1. The return of the arm from folded to extended position is first achieved by manually swinging the arm to a position where the center of gravity of the arm intersects a line perpendicular to the horizontal. The hydraulic cylinder 36 and chains 464ii then take over and support the lowering of arm to a desired position and support the arm in such position during the loading or unloading operation.

What I claim as new is:

1. In a loading apparatus of the character described, a boom mounted for vertical swinging at its outer end, an extension lever arm pivotally attached, at its inner end to the outer end of said boom for vertical swinging adjustment relative to the boom, a retractable and extendable power means mounted on the boom and a chain connection between said power means and said extension lever arm for effecting the swinging adjustment thereof incident to the extending and retraction of the power means.

2. In a loading apparatus of the character described, a boom mounted for vertical swinging adjustment, an extension lever arm pivoted at its inner end to the outer end of said boom for vertical swinging adjustment relative thereto, a power cylinder mounted on the boom,

having an extendable and retractable piston rod, a leaf chain connected at one end to said piston rod and at its other end to said extension lever arm through which support and swinging adjustment of the lever arm is effected by the power cylinder.

3. The loading apparatus of claim 2 wherein said extension lever arm is mounted on the outer end of the boom by a horizontal pivot pin and wherein an arcuate chain guide track is mounted about said pivot pin along which track said leaf chain is drawn under tension and passed for the swinging adjustment and support of said lever arm. 4. The loading apparatus of claim 3 wherein said boom is swingable in a vertical plane between upwardly and downwardly directed positions, and said extension lever arm is swingingly mounted at the end of said boom for swinging between various angular positions, extended beyond the boom end to a position folded back and along the top of the boom.

5. The apparatus of claim 3 wherein the radius of the chain guide track increases progressively, relative to the pivot axis and wherein said leaf chain, between its end connections with the piston rod and lever arm lies along and against the track for the swinging adjustment of the lever arm to give increased lifting leverage as the extension lever swings outwardly.

6. In an apparatus of the character described, a boom pivotally supported to swinging in a vertical plane, and having an upwardly offset bearing portion at its swinging end, an extension lever arm mounted at its inner end on the outer end of said boom for vertical swinging at its outer end, a casting fixed to the inner end of said lever arm providing a bearing coacting with that at the end of the boom, and a horizontal pivot pin extended through said coacting bearings for the pivotal mounting of said lever arm; said casting embodying a chain guide track, extended about said pivot pin and progressively increasing in radius, a power cylinder pivoted on the boom having an extendable and retractable piston rod, and a link chain fixed at its end to the piston rod and to the lever arm and lying along and upon said chain guide track for the swinging adjustment and support of said lever arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,639,826 Welden May 26, 1953 2,895,622 Sundin July 21, 1959 FOREIGN PATENTS 204,736 Austria Aug. 10, 1959

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