US2615748A

US2615748A - Grab

Info

Publication number: US2615748A
Application number: US72816A
Authority: US
Inventors: Walter J Olson
Original assignee: American Brake Shoe Co
Current assignee: American Brake Shoe Co
Priority date: 1949-01-26
Filing date: 1949-01-26
Publication date: 1952-10-28
Anticipated expiration: 1969-10-28

Description

4; Sheets-Sheet 2 Oct. 28, 1952 w. J. oLsoN GRAB Filed Jan. ze, 1949 MOE l n NQ @s Q D D I l D l O D O I l l l O l I C l l I O A INVENTOR. WALTER J. OLSON Y BY f ATTORNEYS W. J. OLSON Oct. 28, 1952 GRAB 4 SheetsFSheet 3 Filed Jan. 26, 1949 Flan INVENTOR. WALTER J. oLsoN ATTORNEYS W. J. OLSON Oct. 28, 1952 n GRAB 4 Sheets-Sheet 4 Filed Jan. 26, 1949 Illlw i.: n l

INVENTOR. WALTER J. OLSON ATTORNEYS Patented Oct. 28, 1952 ican Brake Shoe Company, New York, N. Y a corporation of Delaware Application J anuaryZB, 1949, Serial No. 72,816

6 `Claims.

This invention relates to grabs and more Vparticularly to grabs of the type especially well adapted for use with power hoists in factories, foundaries, and similar places, for'picking up and transporting heavy articles such as molds, asks, heavy stacks of sheet metal, and the like.

Grabs and grapples of the general nature to which this invention relates have heretofore been employed in lifting and transporting heavy articles such as molds, flasks, stacks of material such as sheet metal, and the like, such grabs commonly being used in 'conjunction with hoists, gantrys, trolleys, and other types of power lifting machinery. In such use of the grabs, the'grabs are normally suspended from the power lifting machinery and are used thereon as a grappling -member for gripping or grabbing the work to be hoisted.

Various types of grabs have been heretofore known and used in the art. However, such grabs have had several inherent disadvantages such as, for example, being costly and diicult to manufacture; being diiiicult to operate, and the like.

The primary object of my invention is to overcome these disadvantages and to afford a novel grab which may be economically manufactured and is efficient in operation.

One of the primary disadvantages of grabs heretofore known in the art has been that various parts have been so constituted and arranged that excessive binding of yvarious movable parts thereof occurred during operation of the grabs, and especially when the grab is being operated under load.

One of the principal objects of my invention is to afford a novel grab wherein the various parts thereof are constituted and arranged in a novel and expeditious manner whereby the movable parts operate efticiently and freely when the grab is being operated either with or without a load.

An object ancillary to the foregoing is to afford a grab having grappling arms for engaging the work-load, wherein the grappling arms are supported on rollers in a novel and expeditious manner whereby the arms may be relatively easily moved into and out of work-engaging position.

Another object of my invention is to afford a grab of the aforementioned type wherein the grappling arms are guided and supported by rollers in both a horizontal and vertical direction, and in a novel and expeditious manner.

A further object of myfinvention is to afford a novel grab embodying a frame in'which the grappling armsare supported by rollers in a novel 2 manner whereby the parts of the different grappling arms embodying the rollers may be moved past each other in the frame.

Another common disadvantage of grabs heretofore known to those skilled in the art has been that the grabs have often been diilicult to operate unless the operator could assume a more or less specific position withrelatlon thereto. y

Another object of ymy invention is to aord a grab wherein the operator may readily operate the grab from a number of different rpositions relative thereto. 1

An object ancillary -to the Aforegoing is to provide a grab havingnovel controls for opening, closing and latching the grappling arms thereof, and which controls may be readily reached and operated by an operator-disposedabova below or on the same level as the grab.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of -illustration, show a preferred embodiment and the principles thereof 'and what I `now consider to be the best mode in which I have contemplated applying those principles. `Other embodiments ofthe invention embodying the same or equivalent principles may be used and structural Vchanges may bernade as desired by vthose skilled in the, art without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. l is a top plan view of a grab embodying the principles of my invention;

Fig. 2 is a `detail plan view vof a portion` of the grab shown in Fig. 1 and'with` certain parts thereof being brokenaway;

Fig. 3 is a sectional'view taken substantially along the line 3-3 in Fig. 1;'

Fig. 4 is a sectional view taken substantially along the line 4 4 in Fig. 1;

Figs. 5, 6, 7, and 8 are detail sectional views `taken substantially along the lines v5;---5, 6 6,

1 1, and 8'8, respectively, in Fig. 3

Fig. -9 is a detail sectional view takensubstan'- tially along the line 9-9 in Fig. 5;

Fig. 10 is a detail sectional view taken substantially along the line Ill- I0 in Fig. 1; and

Fig. 11 is a detail elevational view of the mech'- anism shown in Fig.k l0, looking in thedirection of the arrows Il l I in the latter figure.

`The grab 20 vshown in` the drawings to illustrate a preferred embodiment of my invention.

comprises, in general, a frame 22 on which are movably mounted two grappling arms s2,4 and 25,

the grappling arms being adapted to be moved toward and away from each other longitudinally of two elongated boxes or guide-

housings

21 and 28 included in the frame 22. The boxes 21 and S are disposed in parallel spaced relation to each other and are connected at their end portions by two side bars 3G and 3|, Fig. 1.

The box 21, Figs. 1,. 2 and 3, comprises a top wall 32, two

side walls

34 and 35 and a bottom Wall 31, the walls being formed of suitable material such as sheet metal and being connected together by suitable means such as welding 39. A vertically disposed partition wall 40 is mounted between the top wall 32 and the bottom wall 31 substantially midway between the side walls 34 and and is disposed in parallel relation to the side walls 3A. and 35 to thereby divide the box 21 into two chambers 21A and 21B.

The box or guide-housing 28, Figs. 1 and 4, like the box 21, comprises a top wall 52, side walls 'is and 55 and a bottom wall A vertically disposed partition wall 5G is mounted between the top wall 52 and the bottom wall 51 midway between the side walls 5i and to thereby divide the box 2S into two

chambers

28A and 28B.

Two

lugs

59 and 60 are4 mounted on and extend upwardly from the

top walls

32 and 52 of the boxes 21 and 2S, respectively, and are adapted to be engaged by the usual hook, not shown, on a hoist or crane, whereby the grab may be lifted and transported by the hoist or crane.

Four carriages 6|, 62, 63 and 64 are mounted in the

chambers

21A, 21B, 28A and 28B, respectively, Fig. 1, and are operable to movably support the grappling arms 24 and 25 from the boxes 21 and 23, as will be discussed in greater detail presently. Each of the carriages 6|, 62, 63 and 64 comprises an elongated body member E6, Fig. 3, having two pairs of rollers 68 and G9 rotatably mounted on shafts 1| and 12 extending through the lower portion of the body member 15, each of the

rollers

68 and 69 in each of the pairs being disposed on the side of the body member 66 opposite to that on which the other roller in the same pair is disposed, and each of the

rollers

68 and 89 projecting downwardly below the lower edge portion of the body member 66 to thereby afford a peripheral edge portion which may rest on the bottom wall of the guide-housing within which the carriage is disposed. Two other pairs of rollers 13 and 19 are rotatably mounted on shafts 8| and 82 which extend through the upper portion of the body member EES in substantially vertical alignment with the shafts 1| and 12, the rollers 13 and 19, projecting above the body member GS to thereby afford a peripheral edge portion engageable with the top wall of the guidehousing within which the respective carriage is mounted to thereby aiord means for retaining the

lower rollers

68 and 69 in engagement with the bottom wall of the housing.

In addition to the vertically disposed

rollers

68, 69, 1S, and 1S, each of the carriages lil-64, includes two rollers S5 and 86 horizontally disposed in slots B8 and 89 formed in opposite end portions of the body member G6 of the carriage, the

rollers

85 and 86 being rotatably mounted on pins 9| and 92, respectively, extending in a vertical direction through the slots 88 and 80, respectively. Each of the rollers 85 and 36 projects horizontally outwardly from the sides of the body member 06 past the

rollers

68, 69, 18, and 19, and is adapted to engage the adjacent side wall and the partition wall of the housing within which the carriage is disposed to thereby aiord guide means for guiding the carriage between the aforesaid side wall and partition wall of the housing within which the carriage is disposed to thereby aiiord guide means for guiding the carriage between the aforesaid side wall and partition wall of the housing during movement of the carriage longitudinally of the latter.

Hence, it will be seen that the carriages 6 |-64 are well supported and guided for relatively frictionless movement longitudinally of the

housings

21 and 28, within the chamber in which the respective carriage is disposed, the rollers 68, E9, 18, 19, 85, and 86 on the carriage aiording rolling contacts between the carriage and the walls of the chamber. Also it will be seen that with the carriages 6|-B4 disposed in individual chambers, the carriages may be moved in a longitudinal direction back and forth past each other without danger of striking each other.

The grappling arm 21 is similar to the grappling arm 24, including a jaw member which is connected to the lower end portion of drop legs ||3 and il@ by bolts ||5 which extend through the jaw member into gusset plates |1 and ||8 welded to the lower end portions of the drop legs |13 and H4.

The upper ends of the drop legs |03, |04, ||3 and Hfs are welded to the outer ends of the body members of the carriages 62, S4, 6| and E3, respectively, Figs. 3 and 4. Guard members |2|, 422, |23, and |24, Figs. 1, 3 and 4, are mounted on opposite end portions of the

top walls

32 and 52 of the boxes 21 and 2S, and have biiurcated lower end portions projecting downwardly over the upper edge portion of the outer end portions of the body members 63 of the carriages 6|, 52, E3 and 64, respectively, the guard members |2|-|24 acting as end blocks engageable with the rollers 18 on corresponding carriages lil-G4 to thereby prevent the carriages from being completely withdrawn from the boxes 21 and 23.

Hence, it will be seen that the grappling arms 24 and 25 are mounted on and suspended from the carriages l-i/l, and are movable therewith longitudinally of the

housings

21 and 28 between the outer positions wherein the rollers 18 on carriages iii- E21 engage the guards l2 ||24, respectively, and the inner positions wherein the drop legs |03, 50G, ||3 and ||4 engage the outer end portions of the bottom walls 31 and 51 of the

boxes

21 and 20.

Also, it will be seen that in my novel grab, the grappling arms 2li and 25 and the carriages 2l- 54 are so constituted and arranged that the grappling arms may be readily adjusted relative to each other through a relatively wide range of positions. However, it will be understood that, if desired, the range of movement of the grappling arms 24 and 25 may be increased in various ways by those skilled in the art, such as, for example, affording slots in the bottom walls 31 and 51 of the guide-housings 21 and 2S into which the drop legs |03, |06, ||3 and ||4 may be moved during inward movement of the grappling arms 24 and 25, without departing from the purview of my invention.

To afford means for moving the grappling arms 24 and 25 toward and away from each other I provide two endless chainsv |28 and |29, Figs. 3 and 4, which are trained over two pairs of sprocket Wheels |3| and |32, and |34 and |35, respectively. A reinforcing bar |39 extends between and is welded to the central portions of the

side bars

30 and 3| of the frame 22, and the sprocket wheels |32 and |34 are mounted on, and rotatable with, the opposite end portions of a shaft |31, which extends through the supporting bar |39 and is journaled in brackets |40 and |4| which are welded to, and project downwardly from, the bottom walls 31 and 51 of the

guidehousings

21 and 28, respectively. The sprocket wheels |3| and |35 are mounted on, and rotatable with, stub shafts |43 and |44, which are journaled in brackets |46 and |41 also welded to and projecting downwardly from the bottom ,walls 31 and 51 of the guide-

housings

21 and 28, re'- spectively.

As is best seen in Figs. 3 and 4, the chain |29 is disposed on the pulleys |3| and |32, below the housing 21, in such a position that vertically spaced upper and lower runs or passes |5| and |52, respectively, are afforded thereon; and the chain |29 is so disposed on the pulleys |34 and |35, below the housing 28, that vertically spaced upper and lower passes or runs |54 and |55, respectively, are afforded. As will be described in greater detail presently, the chains |28 and |29 are connected to the legs |03, |04, ||3 and ||4 of the grappling arms 24 and 25 in such a manner that upon rotation of the chains |28 and |29 in one direction the grappling arms 24 and 25 are moved along the guide-

housings

21 and 28 toward each other, and, when the chains are rotated in the other direction, the grappling arms 24 and 25 are moved along the

housings

21 and 28 away from each other.

Interconnection of the drop legs |03, |04, ||3 and ||4 with the chains |28 and |29 is effected by elongated links or rods |6|, |62, |63 and |64, respectively, Figs. 3 and 4, the rods |6|, |62, |63 and |64 being. connected at one end to the drop legs |03, |04, ||3 and ||9 by suitable means such as pins |66, and being connected vat the other end to the chains |28 and |29 by brackets |68 or |69. As is best seen in Figs. 3 and 8, each of the brackets |68 are mounted on the last mentioned end of a respective one of the rods |6| and |62 and is held thereon by a nut |10, and includes a crossbar |1|, Fig. 8, which extends through a link of one of the upper passes |5| or |54 of the chains |28 and |29 to thereby attach the rod to that chain. Similarly, as is best seen in Figs. 4 and 6, each of the brackets .|39 are mounted on a respective one of the rods |63 and |64 and is held thereon by a nut |12, and includes a crossbar |13, which extends through a link of one of the lower passes |52 or |55 of the chains |28 and |29 to thereby attach the rod to that chain.

Hence, it will be seen that as best shown in Figs. 3 and 4, the legs |03 and |84 of the grab 20 shown in the drawings are connected to the upper runs |5| and |54 of the chains |28 and |29, respectively, by the rods |6| and |82, respectively, and the legs ||9 and |20 are connected to the lower runs |52 and |55 of the chains by thefrods |63 and |64, respectively. Therefore, it will be apparent that upon rotation of the chains |28 and |29 in a clockwise direction, as Viewed in Fig.r 3, the grappling arms 24 and 25y will be moved along the guide-

housings

21 and 28 toward each other, whereas, when the chains are rotated in a counter-clockwise direction, the grappling. arms will be moved away from eachother. i

The means by which I prefer to rotate the chains |28 and |29 is best shown in Figs; l, 10 and 11 and includes a vertically disposed elongated supporting bar |15 welded to the outerend portionof the reinforcing .bar |39. -Two Vshafts |11 and |18 having hand wheels |80 and 18| mounted thereon, respectively, are journaled in bearings |83 and |84 welded to the opposite fend portionsof the supporting bar |15, the hand wheels and |8| being secured toand-rotatable with the shafts |11 and |18.

As is best seen in Figs. 10 and ll, thehand wheels |80 and |8| are operatively interconnected by an endless chain |86 trained oversprocket wheels |88 and |89 mounted on the shafts |1-1 and |18, respectively, so that upon rotation .of either of the hand wheels |80or |8| a like rotation of the other hand wheel is effected. `A second sprocket wheel |9| is mounted on and :rotatable with `the shaft |11 and is operatively connected by an endless chain |94 to a sprocket wheel |92 mounted on and rotatable with the` shaft |31, Figs. 1 and 10. Thus, it will be seen that upon rotation of either of the hand wheels |80 or IBI, the shaft |31 is caused to rotate in the bearings |40 and |4l, thereby causing the sprocket wheels |32 and |34 to be rotated and effecting rotation of the chains |28 and |29 about the two pairs of sprocket wheels |3| and |32, and |34 and |35, respectively.

brackets

208 and 209 mounted on the opposite end portions of the supporting bar |15 and is connected to the pawl |99 by a link 2|| welded to the pawl |98 and connected to the control rod 203 by va pin 2I2.

In the normal operation of my device, the weight of the control rod 203 and thepawl |98 is normally sufficient to maintain the pawl in engagement with the teeth 20| on the ratchet wheel |96. Therefore, it will be seen that the `hand wheels |80 and |8| and, therefore, the shaft 'rod 203 and moving the control rod 203 upwardly to thereby disengage the pawl |98 from the ratchet wheel |96 and, thereafter, rotating the hand wheel |80 or |8| in a counter-clockwise direction. On the other hand, if it is desired to move the grappling arms 24 and 25 toward each other the hand wheel |80 or |8| may be turned by the operator in a clockwise direction to thereby effect the proper rotation of the chains |28 and |29 to accomplish such closing movement of the grappling arms. It will be remembered that during clockwise rotation of the hand wheels |80 and |8| it is not necessary to hold the pawl |98 out of engagement with the ratchet wheel |96, however, as a practical matter, so as to save wear on the pawl |98 and the ratchet wheel |96, it will often be desired to hold the pawl |98 out of engagement with the ratchet wheel |96 and it will be seen that this may be readily accomplished by moving the control rod 203 upwardly in the manner previously mentioned with respect to rotation of the hand wheels |80 and |8| in a counter-clockwise direction. Thus, it will be seen that opening and closing movements of the grappling arms 24 and 25 may be readily effected by an operator positioned either above or below my novel grab 20.

Operation,

In the operation of the grab shown in the drawings, the grab may be supported from a suitable hoist, trolley, or the like, by hooks, not shown, engaged in the openings of the

lugs

59 and 60 mounted on the upper walls of the

guidehousings

21 and 28.

Normally, in the operation of my device, the grab 20 will be lowered by the hoist, or the like, over the article, or articles, to be lifted and transported by the hoist and, in preparation for such lowering of the grab over the article or articles, the operator may move the grappling arms 2li and away from each other by iirst moving the control rod 203 upwardly so as to disengage the pawl |98 from the ratchet wheel |96 and, thereafter, rotating the hand wheels |80 and it! in a counter-clockwise direc-tion to thereby cause the shaft |31 and the chains |28 and |291 to be rotated in a counter-clockwise direction, as viewed in Figs. 3 and l0, and effect outward movement of the links |8|-|84 and the grappling arms 24 and 25. The grab 20 may then be lowered over the article or articles to be lifted and transported thereby, and the operator may then rotate the hand wheels |80 and |8| in a clockwise direction to thereby move the grappling arms 24 and 25 toward each other into engagement with the work to be lifted. After the grappling arms 24 and 25 are suitably engaged with the work, the control rod '263 may either be moved downwardly by the operator, or may be released by the operator so that it falls by its own weight, to thereby engage the pawl |98 with the ratchet wheel |96 and prevent counter-clockwise rotation of the hand wheels ISU and |8|, such latching of the hand wheels |83 and |8| against counter-clockwise rotation being eiective to hold the grappling arms 24 and 25 against outward InoverneniJ away from each other as previously discussed.

In the operation of my novel grab the work to be lifted thereby may either be gripped between the grappling arms 2l! and 25 or may be disposed on the bars |0| and the particular manner of supporting the work by the grab being determined primarily by the size and contour of the work, However, it will be seen that whichever manner the work is engaged by the grappling arms 24 and 25, the parts of my novel grab are so constituted and arranged that the grappling arms will be positively held against outward movement relative to each other so that they may readily be maintained in engagement with the work,

From the foregoing it will be seen that I have afforded a novel and practical grab wherein the grappling arms of the grab are supported in a novel and expeditious manner, and may be moved relatively freely in either an unloaded or loaded condition during an operation of my device.

Furthermore, it will be seen that I have provided a novel grab wherein the grappling arms may be readily moved in a novel and expeditious manner by an operator disposed either above or below the grab, and, when desired, the grappling arms may be readily latched against outward movement away from each other.

In addition, it will be seen that I have afforded a novel grab which is sturdy in construction, practical and efficient in operation, and which may be economically produced commercially.

Thus, while I have illustrated and described the preferred embodiment of my invention, it is to be understood that this is capable of variation and modiiication and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

l. In a grab, a frame including two elongated boxes, each havingr a top wall, a bottom wall, side walls, and a vertically disposed partition wall dividing said box longitudinally into two chambers, two pairs of carriages mounted in said boxes, each of said carriages comprising a body member and a plurality of rollers rotatably mounted thereon and projecting therefrom, each of said carriages being mounted in a respective one of said chambers in a respective one of said boxes for movement longitudinally thereof with predetermined ones of said rollers in engagement with the said bottom wall of said box, predetermined other ones of said rollers in engagement with the said top wall of said box, and other rollers in engagement with said partition wall and one of said side walls of said box, each of said carriages of each of said pairs being mounted in a chamber of a respective one of said boxes, two grappling members, each of said grappling members being mounted on and suspended from a respective one of said pairs of carriages for movement therewith longitudinally of said boxes, and means connected to said grappling members for moving said grappling members and said pairs or carriages toward and away from each other longitudinally of said boxes.

2. In a grab, a frame including two elongated boxes having a top wall, a bottom wall and side walls, and each box having a vertically disposed partition wall extending longitudinally through the center thereof, two pairs of carriages mounted in said boxes and movable longitudinally thereoi, each of said carriages comprising a body member, and a plurality of rollers rotatably mounted on said body member, each of said carriages of each of said pairs being mounted in a respective one of said boxes with two carriagesA being mounted in each box, respective ones of said two carriages in each box being disposed on opposite sides of the said partition wall in said box, predetermined ones of said rollers on said carriages being disposed in engagement with said top and bottom walls of said boxes for supportingy said body members in said boxes, and other of said rollers on said carriages being disposed in enksaid frame, means including an endless chain interconnecting said sprocket wheelsA forv rota-v gagement with said partition walls in said boxes f for guiding the movement of said carriages through said boxes, a pair of grappling arms, each of said grappling arms being mounted in said boxes and connected to and supported by a corresponding one of said pairs of carriages for movement with said carriages longitudinally of said boxes, and means for moving said grappling members and said carriages toward and away from each other longitudinally of said boxes.

3. In a grab, an elongated frame including two elongated guide-housings each having a top wall, a bottom wall, and two side walls interconnecting said top and bottom walls, and each having a vertically disposed partition wall mounted between said side walls and extending longitudinally of said housings, two pairs of elongated carriages mounted in said housings, said two pairs of carriages being disposed in opposite end portions of said'housings with each of said carriages of each oi said pairs being disposed in a respective end oi one of said housings, each of said carriages comprising an elongated body member disposedlongitudinally in the housing within which said carriage is disposed, a plurality of rollers rotatably mounted in pairs on said body member, predetermined pairs or said rollers being mounted on opposite end portions of said body member and engaged with the bottom wall of the housing within which said carriage is disposed to movably sup port said body member ci said carriage thereon, and other pairs oi said rollers being engaged with the top wall of the housing within which said carriage is disposed to retain said predetermined pairs of rollers in engagement with said bottom wall of said housing, and other rollers rotatably mounted on said body members and engageable with a side wall and said partition wall of said housing within which said carriage is disposed to guide said carriage' in said housing, grappling arms supported by said carriages for movement toward and away from each other, each of said grappling arms being supported by a corresponding pair or" said oarriages and comprising a jaw member and two drop legs mounted on said jaw member, each of said drop legs extending through a corresponding one of said slots in the bottom of one of said housings and being mounted on said body member of one of said carriages, and means for reciprocating said carriages and said grappling arms relative to said housings to thereby move said grappling arms toward and away from each other.

4. In a grab oi the type including a frame, a pair of grappling arms movably mounted on said frame for movement toward and away from each other, a shaft rotatably mounted in said frame, and an endless chain rotatably mounted on said frame and connected to said shaft for rotation therewith, said chain being connected to said grappling arms and operable upon oscillation to move said grappling arms toward and away from each other, means for oscillating said chain to thereby move said grappling arms toward and away from each other, said means comprising supporting means connected to said frame, two hand wheels rotatably mounted on said supporting means with one of said hand wheels being disposed above said frame and the other of said hand wheels being disposed below tion with each other,and means .including an endless chain connecting ,said shaft to oneof said hand wheels for rotation therebyupon roy' tation of said hand wheels.

5. In a grab ci the typeincluding a"frame, a pair of grapplingfarms' movably mounted ron said frame for movement toward and away' from each other, an elongated "shaft rotatably mounted on said framatwoendless f chains rotatably mounted on said frame. and; connected to said shaft for rotation therewith, said chains being connected to said grappling arms and being operable upon oscillation to move said grappling arms toward and` away from each other f on'said frame, the combination of an elongated supporting vmember mounted in yvertically extending' position on said frame, two shafts rotatably mounted on said supporting member on opposite end portions thereof, a hand, wheel mounted on each of said shaftsior rotating the latter, a sprocket wheel vmounted onA the said elongated shaft, two sprocket wheels mounted on one of said two shafts, a sprocket wheel and a ratchet wheel mounted on the other one of said two shafts, an endless chain trainedover said sprocket wheel on said other shaitand over one of said sprocket wheels on said one shaft vinterconnecting said two shaits for rotation with each other, an endless chain trained cversaid sprocket wheel on said elongated shaft and the other one of said sprocket wheels on said one shaft for rotating said enlongated shaft upon rotation of said two shafts, and means, .including a pawl engageable with said ratchet wheel, and a control member for moving said pawl into and out of engagement with said ratchet wheel, for controlling the rotation of said two shafts and, thereby, of said elongated shaft in one direction..

6. In a grab of the type including a frame, a pair of grappling arms movably mounted on said frame for movement toward and awayfrom each other, an elongated shaft rotatably mounted on said frame, two endless chains rotatably mounted on said frame and connected to said shaft for rotation therewith, said chains being connected to said grappling arms and being operable upon oscillation to move said grappling arms toward and away from each other supporting member mounted in vertically extending position on said frame, two shafts yrotatably mounted on said supportingmember on opposite end portions thereof, al hand wheel mounted on each of said shafts for rotating the latter, a sprocket wheel mounted on the said elongated shaft, two sprocket wheels mounted on one of said two shafts, a sprocket wheel and a ratchet wheel mounted on thev other one of said two shafts, an endless chain trained over said sprocket wheel on said other shaft and over one of said sprocket wheels on said one sha-it interconnecting said two shafts for rotation with each other, an endless chain trained i over said sprocket wheel on said elongatedv shaft and the other one of said sprocket wheels on said one shaft for rotating said elongated shaft upon rotation of said two shafts, and means for controlling the rotation of said two shafts and, thereby, of said elongated shaft and said 11 said ratchet wheel for preventing rotation of said two shafts in one direction, and an elongated control rod connected to said pawl and having al handle disposed above said frame and another handle disposed below said frame; for moving said pawl into and out of engagement with said ratchet wheel.

WALTER J. OLSON.

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

Number l2 UNITED STATES PATENTS Name Date Durhan, Jr Jan. 18, 1927 Wazlavek May 26, 1931 Francis Sept. 13, 1932 Hoe Jan. 21, 1936 Windsor Mar. 1'7, 1942 Breslav Dec. 21, 1943 Osterhous Feb. 8, 1949 Maier Jan. 30, 1951