US1630456A - Grab - Google Patents

Description

W. G. WEHR May 319 GRAB Filed Aug. 25, 19.25

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Annemanma Augen at, im.l semi Na. 59,304.

The present invention relates to improvementsgin grabs, and more particularly to grabs of the type in which load engaging hooks or clam ing jaws are 'so mounted that they! are urge jby gravity' toward loadengagging position and are maintained inen-v v gagement with a load by thewe'ight thereof.

#It is an object of the present invention to provide a: magnetically actuated .grab 1n l0 which the interruption of electric current to the electro-maenetic actuator'wil not cause the release of the load.'

The further object is to provide a grab in which the vhooks or jaws are so'connected to l' the suspension member or headblock and the -inovable part ofthe solenoid carried by the suspension member that the actuation of the solenoid will cause the hooks or jaws to be moved to open or load releasing position and tobe held in such a position until the current' through this solenoid is-interrupted.

, With. theabove and other objects in view, the ,inventionr may be said? to comprise the device as illustrated in the several modifications shown in the accompanying drawings hereinafter. described and particularly set forth in the appended claims together with such variations and modifications thereof as will be apparent to one skilled in theartto which'. the invention appertains.

Referencefshould be had to the accompanying drawings. forming a part of this specification. in which Fig',l 1 isa side elevation of a twojaw grab embodyingthe invention; Fig. 2 is a top plan View of the grab shown in Fig. 1; Fig. 3 is theside elevation showing'invention applied to a .modified form of grab; Fig. 4is an end elevationfoflthe grab lshown in Fig. 3: Figs. 5 and 6 show side elevations and a top plan view, respectively.

v'offa grab provided with a series-of radially movable jaws and showing the present inventionapp`ied thereto; Figs. 7, 8 and 9.

show a side'elevation.- en .end elevation and atop plan view. respectively.v of the grab embodying the invention and having two jaws provided 'with laterally spaced load er1-'- raging arms; Figs. 10 and 1'1 show side elerations and a top plan view showing the invention applied to a' grabyfofuthe internally engaging or expander type-fa'nd Figs. 12 and 13 arejsi'de and endlelevatonfsshowing the invention applied to a grab designed for handling loosematerial such as waste paper.

Referrin Aliirst to Figs. 1 and 2, the grab is provider with a suspension member or headb'ock 1 upon which is mounted a sheave 2 which receives the loop of a hoi-st cable 3 by `means of which the grab and the load "carried thereby may be raisedzor lowered. The head block 1 has a lower portion 4 which is hollow and cylindrical forming a casin (Y Yfor the coil 5 of a solenoid which is connected bv a suitable fiexible conductor 6 with a suitable source of current.

'The coil 5 is wound upon a cylindrical tube 7 at the center of the casing 4 and the core 8' of the so`enoid is slidably mounted within the tube 7.

Thev lower end of the casing 4 is provided with an opening 9 through which the lower end portion of the core 8 extends. the core 8 having a sliding fit in the opening 9 andbeingprovided with an enlarged upper portion 10 which has a sliding fit in the tube 7 and which provides a shoulder engageable with the bottom "of the casing 4 to-limit the downward movement of the core. At its lower end the core 8 is connected to the center of a horizontal disposed spacer bar 11.to the opposite ends of which are pivoted the jaws 12 which have suitable engaging 'prongs 13 at theinlower ends and inwardly curved upper end portions 14 above their ivotal connections to the spacer bar 11. he bar 11 may be provided with a plurality of holes 11* at the ends thereof to receive the pins connecting the jaws 12 thereto to adjust the grab for different sized loads. h f

-The upper' inwardly projecting ends of the jaws 12 are connected to,the head block 1 by means of links 15 which are pivoted at their outer ends to the upper end portions 14 of jaws, and at their inner ends to ears 16 formed integrally with the casing 4 on opposite sides thereof. The normalv position which the jaws 12 will assume when the solenoid coil 5 is deenergized is substanthe jaws 12 supported on the bar 11, will n move downwardly by gravity until the enlarged portion 10 of the core 8 rests upon the bottom of the casing 4, the links 15 during the downward movement lof .the core and jaws move toward horizontal position causing more, outwardly and the lower ends thereot' to move inwardly. When current is passed through the solenoid coil 5 the coro 8 is moved upwardly within the coil 5 lifting the spacer bar 11 and causing the links 15 to swing upwardly towards vertical position, drawing the upper ends ot the jaws 12 inwardly and spreading the lower ends thereof apart, this positionot the grab being shown in dotted lines in Fig. 1.

.In the operation ot the grab the overhead support from which the grab is suspended will be shifted to a point directly above the load-to be lifted and the solenoid will be energized to move the jaws to open position.

The open grab will then be lowered until the 'aws thereof are upon theopposite sides ot' t e article to he lifted and the current through the solenoid will'he interruptedto permit the jaws to `tall by gravity into gripping engagement with'the article. lVhen the article so engaged is lifted the weight thereof is added to the clamping jaws tending to cause the jaws to move toward their L lowest position with respect to the head block 1l and into tighter gripping engagement with the load. Ordinarily the solenoid coil 5 will be provided with sufficient Cturns to lift the jaws and move them to releasing position only when they are not carrying afload. In such case it will be necessary to deposit the loadv upon .the ground or upon the pile to take the weight thereof from the grab before the grab is' released. It is obvious, however, that if it is desirable a solenoid may be provided which has sullicient power to release the grab while carrying a load and allowl the load todrop from the grab.

In Figs. 3 and 4 there is shown a grab differing somewhat yin construction ktrom that shown in Figs. 1 and 2, and iny these views the parts corresponding to parts shown in Figs.,1 and 2, and above described, are designated by the sainel reference numerals with the vadded exponent a.

The head block 1a is substantially the same as head block shown in Fig. lrexcept that it has at its upper end an eye 17 to which a hoisting cable .maybe attached. Thesolenoid core 8a, spacer bar 11F, and actuating linksla, are exactly the same as inthe modification above described. The clamping jaws 12,` however, are provided with laterally bent lower portions forming spaced arms 18=connectedby abrace 19. and having load engaging plates 20 .secured to the inner sides thereof. The grab shownV in Figs. 3` and 4 is suitable for handlingi pi es, barrels, paper or other similar cylin drlcal articles, the operation ofv this grab bef the upper ends of the jaws 12l to.

.ing exactly the same. as` descrihedabove in connection with Figs: 1and.f2. l.

Figs. 5 and 6 illustrate the application of l the invention to fa grab whichv fis .provided with a series of angularly'disposed ii'ad'ially movable jaws.' Any numbeivofjrad-iallyfdisposed jaws may be employed,{thethi'ee jaw apart at the lower end thereof.` Three A radially movable jaws 12b are provided instead of the two oppositely disposed jaws shown in Fig. 1. 'l`hojaws`12b are substantially identical'witli the jaws 12 and have their upper,L ends connected by actuating links 15b-to thee-ars 16". `On the head block in this modification the-spacer 11" is in the lform ofa Lspider with ,armsV extending from the center tliei'eot' at v120D to each other, 4each arm -being pivot-ally lc\'iiiiie .'te.d at its outer end to one of the jaws 12" and the central portion of the. spider being connected t0 the core'ot'fy the solenoid. It will be obvious that the-lower ends of the jaws 12b tend to move by gravity toward the vertical axis of the orrab and 'that upon actuation of the solenoid the lower engaging ends the'ja'ws will be moved outwardly.

In Figs.- 7, 8 and 9 of' the drawing. the invention is shown applied to agrab of the type having oppositely disposed jaws with parallel spaced load engaging portions. The parts in theseviews corresponding to parts shown in Fig. y1 are designated-by los.

the-saine refereiice'numerals with the adj dition of the exponent -c.

. The head vblock 1, in this case, is .iden-v tical with vthe head block'shown in Fig. 1 except that vthe ears 16c upon oppo'aitesides of the easing 4 are spaced farther apart. The coi-e 8cl of the solenoid extends through and is rigidlyseeuredto a rigid cross har 21 by nieans' of a nut 22 upoiithe lower end .0f the core.,iThe spacer hars 1'1c are recured centrally lthereof to opposite ends ot the cross bar 21 by bolts Q3, and to the opposite ends of the spacer bars 11c are pivoted the, 'load' engaging jaws 12c which are substantially identical in construction withthe jawsy 12b inFig. 1,'Means is provided for moving the pairs of jaws `on opposite sides'of the head block 1c simultaneously. fand tothis end .eac-h jawv 1Qc is connected at its -npperend by va link 15. with a cross rod 24 extendingl through the ears 16"' 'on oppositev sidesof the head block, and ,through the inner ends-of the links 15e.

"iin

Spacersleeves 25 are provided between theears 16 and the links 15, and: the links 15 are clamped against the outer ends of the sleeves 25 by nuts 26 upon opposite ends of the rod 24.

It will be obvious u on comparison of Figs. 1 and 7 that the li ting of the solenoid core' 8 will Acause the pairs of jaws on opposite sides of tho head block to move simultaneously toward and away from each other to load releasing position, and that when the core 8c is released the jaws will move by gravity into load, ripping position. j

1n Figs. 10 and 11 t e-invention is shown lapplied to a grabl of the type in which the jaws move outwardly instead of inwardly to grip the load. Parts of these modifica.- tions corresponding to arts shown 1n Flgs.

. 1 and 2 are designatet by the same reference numerals with the addition of the exponent d.

The head block 1d is substantially identical with' the head block 1b in Fig. 1, but the actuating rods 15dare inclined downwardly from their points of attachment to the head block instead of upwardly as shown in Fig. 1, and the jaws l2d are in the form of bell cranks which are pivoted at the angle between the arms thereof on a horizontal pin 27 passing through the lower end of the core 8d and through the jaws 12, Each of the jaws 12d has an arm extending outwardly from the pivot pin 27 and connected at its outer end to an actuating link .,151, and an arm extending downwardly from the pivot pin 27 and provided on thc outer side thereof with a series projection 28 for engaging the interior of a hollow article to be lifted by the grab. When solenoidA is energized the jaws 12d will be held `in the position shown in full lines in Fig.

10 with the engaging arms thereof substantially at the plane of the core 8d. When the core 8d is released by interrupting the current through the solenoid coil the core S and the jaws 12d will drop downwardlyv causing the links 15d and the outwardly exlending arms of the jaws 12@i connected thereto to move inwardly and at the same time causing the engaging portion 28 tomove outwardly into engaging position. The weight of the load supported by the jaws 12c1 creates an added downward force on the'pivot 27 tending to move the same downwardly and to press engaging portion 28 ot' the jaws into tighter engagement.

InV Figs. 12 and 13 a further modification ofthe invention is shown.v The parts corresponding to parts shown 'in Figs. 1 and 2 are designated by the same reference numerals with the addition of the exponent He.

T he head block 1e iss'imilar to the 'head block 1a shown in Figs. 3 and 4 except that 4the attaching earsle are adjacent the upper ends of thecasing 4,in place of adjacent the lower." end. The core 8 passes through andv is secured to a rigid cross bar which clamp the outer ends of the bars 11"v against the ends of spacer sleeves 33 which fit upon the rod 31 between the spacer bars. 'lhe jaws 12e are rigidly secured to the spacer sleeves adjacent the ends thereof and at the (enter of' each sleeve 33 .there is an inwardly extending arm 34 rigid-ly secured to the sleeve. Actuating links 15 are pivotally connected to the inner ends of the arms 34 and extend upwardly therefrom to the attaching ears 16* on the head block to which they are pivotally connected. The pozition normally assumed by the grab is shown by full lines in Fig. 12 which shows the core 8* and spa: er bars 11's in their lowcrmoat poition in which thel jaws 12 are held by the links'15 in their innermost or load engaging positions." When the sole no id is energized the lcore 8 together with the spacer bars and jaws mounted thereon are lifted tov osition shown in dotted lines in Fig. 12. he upward movement of the jaws causes the arms 34 which are held by the actuating links 15e to be rocked downwardly and the jaws 12e each are fixed to the saine sleeves 'as arms 34 to be rocked outwardly to load releasing position. In the operation of the grab shown in Figs. 12 and 13 the grap will be positioned over the'loose material to be lifted, the solenoid vwill be energized to move the grab to open position and the grap will then be dropped into the material. The jaws or prongs will enter tliematerial to be lifted and, upon release ot' the solenoid, will tend to -move to load gripping position. When the grab is lifted the weight of the "material engaged by the jaws or prongs 12e will increase the gripping action causing the material between the prongs' to be tightly gripped between the prongs.

Having described my invention, what I cla-im is:

1. A grab comprising a suspension member, a solenoid carried by said member, and having a movable core, load engaging jaws supported by the core 'of the solenoid, and actuating means interposed between' the suspension member and jaws to actuate the jaws when the same are. moved by the solenoid.

2. A grab comprising a suspension member, a solenoid carried by said member. and

having a movable core, load engaging jaws vsupported by the core of the solenoid, and

actuating links connected to. the jaws and to the suspension member.

l nl) -v to open position, and means downward movement of the core.

portions of the jaws when the solenoid is energized. the weight of the core when thersolenoid is deenergized acting to shift the jaws toward load engaging position.

5. A grab comprising a suspension niember, a vertically movable inemher 'arried by the suspension member and normally held by gravity in its lowermost position with respect thereto, jaws pivoted to said movable member, means connecting the jaws and sns- `pension member for automatically moving the jaws to load engaging position during downward movement of said movable member, and to releasing position upon upward movement thereof, and a so enoid for lifting said movable member to shift the jaws to releasinn' position. l

6. grab comprising a head block, load engaging jaws connected to the head block and adapted to move by gravity to load engaging position, and a solenoid carried by the head block, said solenoid having a vertically movable Vcore connected to the jaws and adapted, when the solenoid is energized, to move the jaws .to releasing position, the weight of Ksaid core when the solenoid is deeucrgized acting upon said jaws to move them toward load engaging position.

7. A grab comprising a head block. load engagingjaws, links connecting the upper portions of the jaws to the head bl0ckand a solenoid carried by the head block and having a Core Connected with the jaws intermediate the ends thereof.

8. A grab comprising a head block, load engaging jaws pivotally connected at their upper ends to the head block and adapted to move by gravity to load engaging position, a vertically disposed solenoid mounted in the head block centrally thereof, said solenoid having a core connected to the jaws intermediate tlie ends thereof and adapted', when the solenoid is energized` to move the jaws j 9. A grab comprising a head b`ock, load engaging jaws, links connecting the upper to the head block, a

for limiting the` solenoid mounted in the head block centrally thereotl and having a vertically dis osed core, means connecting the .lower end o said core to said jaws intermediate the ends thereof. and means for limiting the downward movement of the core.

lt). A grab comprising a head block. links pivoted at'. their inner ends to the head block, jawsl pivotally connected to the outer ends of the links, and adapted to movevv bodily with respect to the head block. means connecting said jaws and empi-,rating with said links to cause the jaws to be normally held by gravity in load engaging position, and a solenoid having a vertically movable core connected to said connecting means for shifting the same to move the jaws to load releasing position.

l1. A grab comprising a head block, links pivotcd at their inner ends to the head block, jaws pivoted to said links. means for supporting said jaws'comprising a rigid spacer Apivoted to the jaws below the pivotal connections between the jaws and links and a member carried by the head block which is connected to the spacer and has a limited vertical movement with respect to the head, and mea-ns on the head for shifting said member to actuate. the jaws.

l2. A grab comprising a head block, a rel; neid mounted in the head block` and having a vertically disposed core adapted to be li'ltcd when the solenoid is energized, means forlin'iiting` the downward movement of the' core, a rigid spacercarried by the core, jaws pivoted on said spacer, and actuating links connecting said jaws tojthe head block to move the jaws to open position when 'the saine are lifted by the solenoid. Y

13. A grab comprising a head block, a solenoid carried by the head block and having a vertically movable core adapted to be lifted when the Solenoid is energized and to drop by gravity when'the solenoid is deenergized, means for imiting the downward movement of the core, load engaging jaws supported by the core, and means interposed between the head block and jaws for opening the jaws when the same are lifted by the solenoid and for closing the jaws upon release of the solenoid.

l-l.. A grab comprising a suspension member, jaws pivotally suspended from said member, a. vertically .disposed solenoid earried by said suspension member and a weight connected to said jaws to close the same. said weight forming the core of said solenoid and acting to open the jaws when the solenoid is energized.

In testimony whereof, I hereunto affix my signature.

WILLIAM G. -WEHR

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