US2279570A - Grabhooks - Google Patents

Description

April 14, 1942.

- J. KAMPP GRAB HOOK To Hn/ls'T/y Mechanism.

Filed June` 6, 1941 A TTa//VE Y Patented Apr. 14, 1942 UNITED STATES PATENT OFFICE `2,279,570 GnABnoiis Jacob Kamppi, Astoria, Oi'eg. Application June a, 1941, serial No. 396,883 v Claims. (lol. 2'94112) My invention relates to load lifting and engaging apparatus and is particularly designed for use in lifting round or cylindrically-shaped objects. In this connection, it has particular utility in loading logs. At the present time it is a common practice to engage logs, eitherv in loops or bights of line, or to Vengage them in tongs having relative sharp `points which sink into the logs and are thus secured thereto. With tongs of this character,v the logs are frequently punctured to such a depth that a substantial amount of lumber is thus damaged. This is relatively unimportant when logs are used to make rough timbers, but is quite important when so-called` peeler logs are loaded. Peelerf logs are used in making veneer stock and the most valuable portion of the log is the external surface thereof, because such surface is more free of knots, pitch pockets and other defects and thus produces more clear ply or veneer stock.

Logs are normally stacked on a truck or on a flat car in a pile and thus the loading mecha# nism must be designed so that the loading tongs or lines can be freely disengaged without disturbing the stacked relationship. Thus, if loops or bights of line are used for liftingy the logs, the line cannot freely be removed without tending to roll the logs, with consequent disturbance to the stack and consequent danger to the operator.

The object of my invention is to provide tong devices in load engaging apparatus of lthis character, which may engage the logs securely but without damaging them; said tongs' are also designed so that they will open yonly sufficiently to take hold of a log or other object, to quickly and rmly engage a log and lift it into position. The connections are arranged so that the tongs can be easily and quickly disengaged, frequently without manual aid of an operator at the tongs.

A further and more specic object of my invention is to providetongs of this character, which may engage spherical or irregular objects, similar to so-called grappling hooks, and may set such objects down without causing them to roll.

Further and other detailed objects and advantages of my invention are hereinafter referred to with reference to the accompanying drawing, in which:

Fig. l is a more or less diagrammatic view of a spar' tree and loading boom, utilizing load engaging apparatus involving my invention;

Fig. A2 is a plan View of loading tongsl embody ing my invention, looking downwardly upon the upper or non-work engaging faces thereof; l

Fig. 3 is a side elevation of such tongs, with portions shown broken away to disclose details of construction;

Fig. 4 is av sectional view taken substantially on the line 4-4 in Fig. 3, illustratingthe manner in which said tongs may be utilized for gripping an object of circular cross section; and l Fig, 5 is a sectional view taken on the line 5-`5 in Fig. `3, showing a sectional detail of one of said tong members. Y

My invention concernsmost directly, the constructioncof tong devices and load engaging apparatus, which devices comprise a pair of tong members l and Y2, pivotally joinedtogether at one end by a bolt 3. Said bolt connection purj p'osely is not varranged at the vextreme end of this tong member, thus the end la of tong memberV i extends beyond the pivotal bolt connection and engages a flange 2a on the other tong member. This limits the outward movement ofthe tong members as is illustrated in Fig. 3. The tongs may be swung forwardly to the position shown in Fig. 3 as the outermost limit, and I prefer that said tongsl be openable to a lesser degree'. I preferably define the maximum dis-l tance to which `the tong members may bexspread apart to a position in which vthe extremities Ib and 2b are arranged substantially in parallelism.`

It is .to be noted that the tong members are curved or cupped upon a relatively wide sweep and said extremities carry prongs thereon which extend normal to the sweep of the tongs at that point. Saidk prongs face inwardly that is, toward each other, and arev of such lengths that they are shorter thanthe degree of cupping of each of the tong members. I preferably proportion saidtong members I and 2 and the engagement of the ends la and 2a, respectively, so that the tong members maybe arranged to straddle an object with the extremities parallel rather than slightly divergent as shown in Fig. 3. Thus,y

when the tongs are lifted by the mechanism hereinafter described, said extremities lb and 2b may move quickly toward each other vto engage a log 5 or a boulder 6 by its sides with the prongs 4 arranged slightly below the diameter thereof. That is, said log or boulder is arranged in the cup of the tongs and the prongs 4 onlyprovide means to prevent the log or boulder from'slip` ping out of the prong member. The prongs', of course, may not easilyv dig into a rock or other hard objectxandit is" essential that they ynot puncture a barrel or other container-l It is not desirable either that said prongs project thru the bark of a log to make holes in the outer or sapwood of the logs as has previously been commented upon.

Each of the tong members is provided with a series of corrugations 'I which form projecting longitudinally extending ribs 8 to prevent the tongs from slipping longitudinally of the log, and to accommodate any irregularity in a boulder or other circular or spherical object. The prongs are also corrugated, ribbed or otherwise serrated, as is shown in Fig. 5, so that therev is a multiplicity of points 4a underlying the object or en-l Another set of lines is provided for lowering and releasing the tongs. These lines include a bridle section of chain 22. That is, said chain is bifurcated, one end 22a being secured to link I6 and another end 22h being secured to bracket I2 as is illustrated in Fig. 3. Said length of chain.

is to be disengaged or released from the tongs,

gaging to a limited extent, the periphery of the object held by the tongs. Then said tongs preferably diverge toward their extremities as shown in Fig. 2 and longitudinal anges 9 extend along their longitudinal margins. Said anges extend away from the engaging surface of the tongs and provide stiffness for said tongs. The corrugations 'I extend fan-shaped toward the extremities, that is, they diverge toward the extremities as shown in Fig. 2, and thus said corrugations tend to form a plurality of Vs on'the gripping surface of the tongs to prevent longitudinal slipping of the object in said tongs withoutdamaging the surface unduly, which supplement prongs 4 in their action.

The pivotal bolt connection 3 for the tong member passes thru the flanges of the tong members, as is shown in Figs. 2 and 3 and also secured between such anges adjacent to said pivotal connection is a bracket I carrying Ia sheave II. Another bracket I2 is riveted, bolted or welded to the back of tong member I and carries a sheave I3 journalled therein. Said bracket I2 is secured to the back of tong member I at a point intermediate the ends of the latter,V as is shown most clearly in Figs. 3 and 4 and preferably is arranged at a point above the top of any potential load to be engaged by said tongs as is shown in Fig. 4. Said bracket I2 overlles |an elongated slot I4 in tong I, so that the sheave I3 may extend into said slot a substantial distance.

A exible element such as, for example, chain I5 is secured to a link I6, passing thru and engaging the tong member 2 at a point thereon substantially opposite sheave I3. Said ilexible element or chain I5 extends across the space between the tong members land takes a bight around sheave I3 and another bight under sheave II and is joined to one end ofl a cable I'I, which, in turn, is connected to a hoisting Vmechanism, indicated but not shown in Fig. 1. Preferably, when the logs are being loaded, there are two sets of tong members carried by or suspended from a loading boom I8 supported and extending laterally from a spar tree I9. Thus, one set of tong members is secured to one end of said cable I'I and the other set to the other end f thereof. Loading line 20 passes thru a block 2| engaging an intermediate portion of the cable I'I; thus both sets of loading tongs are lifted simultaneously. It is not to be assumed that the specific rigging arrangement is required to practice my invention, but the type shown is illustrated to disclose one embodiment of my invention and its means of. use. When the loading line 20 is pulled by the loading mechanism, it

takes up the slack in chain I5 and pulls the extremities of the tongs toward each other to engage a log as shown in Fig. 1. Further. pull on said loading lines causes both ends of the log to be lifted upwardly toward the under sideof the loading boom.'

the loading line is slacked oif and the lowering line 24 is made taut. This tends to pull the tong Y members apart by pulling on the cable ends in the direction shown in arrows in Fig. 3. It is to be understood that the tong members are quite heavy and have substantial mass and the upper or pivoted ends of the tong members are substantially heavier than the extremities thereof. Thus when the tongs are supported by chains 22, the central portion, including the pivotal connection, bracket I0, sheave II and-the other mechanisms thereto, tend to move downwardly until the end I a abuts with the flange 2a to limit the outward movements thereof. Thus, by putting tension in the lowering line 23, a .log or other object can be readily disengaged from the tongs without much effort. Also, the log or other object does not tend to roll, because the tongs are arranged only at the side of the log or other object and move directly away from said side, without tending to roll or tip thelog or other object, in effecting its disengagement. Thus the tongs embodying my invention set the log or other object down without any great difficulty.

Inasmuch as my invention does not pertain directly to the details of the loading mechanism nor to the specific rigging therefor, I have not attempted to describeall of the details of the rigging nor the manner in which the logging boom is secured t0 the spar tree. As a matter of fact, my invention is not limited to operating with a logging boom or spar tree, but is adaptable to any type of loading apparatus or rigging therefor. It relates to the rigging only assaid rigging is necessary to lift the tongs, bring them together to engage lan object and to disengage them, when the object engaged is .to be released,

as I have previously described,

I claim:

1. In load engaging apparatus, a pair of `tongs pivotally joined together adjacent one end, the opposed faces of said tong members being slightly curved toward eachother and inturned serrated prongs formed at the free extremities of each of said tong members, extending substantially normal to thecurved face of each tong member, said prongs being of such length .as to b e less than the maximum Vrise of the'arc formed by the tong member upon which they are for-med.

2. In load engaging apparatusya pair of vtongs pivotally joined together adjacent one end, the opposed faces of said tong members being slightly curved toward each other, and longitudinally extending ribs extending fan-shaped alongthe face of each of said tong members.

3. In load engaging apparatus, a pair of tongs pivotally joined together adjacent one end, the opposed faces of saidv tong members being slightly curved toward each other, operating connections for said tongs comprising a flexible element secured to o'netong member and engaging the other in a bight of said element, functioning to draw said members towards each other and to lift said tongs, means for spreading said tong members apart, and a stop for said tongs limiting the relative outward movement thereof to a point where the free extremities of said tongs are in substantial parallelism with each other.

4. In load engaging apparatus, a pair of tongs pivotally joined together adjacent one end, the opposed faces of said tong members being slightly curved toward each other, operating connections for said tongs comprising a iiexible element secured to one tong member and engaging the other in a, bight of said element, functioning to draw said members towards each other and to lift said tongs, a guide element secured to said tongs adjacent their pivotal connection, about which guide element said iiexible element passes, and a bridled connection joined to said tong members adjacent the point of securing and engaging of said flexible member, respectively, with the tong members for spreading said tong members apart.

5. In load engaging apparatus, a pair of tongs pivotally joined together adjacent one end, the opposed faces of said tong members being slightly curved toward each other, operating connections for said tongs comprising a exible element secured to one tong member and engaging the other in a bight of said element, functioning to draw said members towards each other and to lift said tongs, a guide element secured to said tongs adjacent their pivotal connection, about which guide element said flexible element passes, a bridled connection joined to said tong members adjacent the point of securing and engaging of said exible member, respectively,

with the tong members for spreading said tong members apart, and a common link securing said connections and said flexible element to a tong member.

6. In load enga-ging apparatus, a pair of tongs pivotally joined together adjacent one end, the opposed faces of said tong members being slightly curved toward each other, inturned serrated prongs formed at the free extremities of each of said tong members, extending substantially normal to the curved face of each tong member, v

.opposed faces of said tong members being slightly curved toward each other, inturned prongs formed at the free extremities of each of said tong members, extending substantially normal to the curved face of each tong member, said prongs being of such length as to be less than the maximum rise of the arc formed by the tong member upon which they are formed, operating connections for said tongs comprising a flexible element secured to one tong member and en. gaging the other in a bight of said element, functioning to draw said members towards each other and to lift said tongs, means for spreading said tong members apart, and a stop for said tongs limiting the relative outward movement thereof to a point where the pronged ends are in substantial parallelism with each other.

' JACOB KAMPPI.-

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