US2337177A - Lifting grab - Google Patents

Description

Dec. 21, 1943. J; BRsLAv- LIFTNG GRAB Filed Oct. 8, 1942 2 Sheets-Sheet 1 INVENToR Jack Breslau W ANEY Dec. 21, 1943.

J. BRESLAV LIFTING GRAB Filed Oc't. V8, 1942 2 sheets-sneet 2 lNvENToR JckBresZzr.

ATTONEY Patented Dec. 21, 1943 UNITED STATES PTENT OFFICE LIFTING GRAB Jack Breslav, New Haven, Conn.

Application October 8, 1942, Serial No. 461,343

7 Claims.

This invention relates to lifting grabs and more particularly to improvements in gi'abs having arms on which stock gripping jaws are pivoted and which are movable toward and away from each other.

In grabs of this nature there is generally provided means to releasably lock the arms in open position and this means may be Semi-automatic in operation, being manually operable to release, or be fully automatic by being released by proper aotuation of the grab. The stock gripping jaws are usually pivoted to the lower ends of the arms and when released from the stock are apt to swing inwardly toward the same and jam against it whereby the stock may be mutilated or the jaws may dig into the stock and be jammed thereagainst thus preventing the proper release thereof from the stock In other instances the pivoted jaws may swing downwardly when open to such an extent that. upon being lowered to again grip stock, they W111 improperly engage the stock and cause damage thereto and danger of accidental injury to the operator.

In order to obviate the above and 'other disedvantages it is proposed as one object of this invention to provide in a grab of the above type improved means to contro1 the swinging movement of the pivoted jaws.

Another obiect of this invention is to provide in a grab of the above type and which has releasable means to hold the arms thereof in open position. means to movably maintain the pivoted jaws in the last position of stock gripping while the arms are held in open position, so that the jaws will not interfere with. the operation of positioning them to grip stock of different dimension.

Still another object of this invention is to provide in a grab having arms movable toward and away from each other and which carry stock gripping jaws pivoted thereto, means carried by the jaws and spring biased into engagement with the arms to fric'cionally reta-in the jaws in the position, assumcd thereby in gripping stock, when they are opened to release the stock, and While hold open by the means to hold the jaws in open position.

A further object of invention is to provide an iinprovezi. stock lifting grab which will be relatively simpie in construction, inexpensive to manufacture, readily manipulated, compact, and very eincient and durable in use.

With these and other objects in view, which will appear as the description proceeds, there have been illustrated in the accompanying drawings forms of grabs in which the features and principles of this invention may be conveniently embodied in practice, it being understood that Various changes may be made within the scope of what is claimed, without departing from the spirit of the invention.

In the drawings:

Figure 1 is a side view of an improved form of stock lifting grab having releasable means -to hold the jaws in open position and embodying the features of this invention;

Figura 2 is a bottom view of the grab and looking in the direction of arrows 2-2 in Figure 1;

Figure 3 is an enlarged sectional view taken on the line 3-3 of Figure 1; and

Figure 4 is a broken partial side view of a gi'ab having a fully automatic form of means to releasably hold the jaws in open position.

Referring now to the drawings, wherein like reference numerals designate like parts throughout the several views, the numerals Il and 12 denote depending opposing arms which are adapted to be moved toward and away from' each 'other to grip stock |3, in'dicated by dotted lines in Figure 1, between jaws |4 and E5, respectively, which are carried and pivotally secured to thelower ends 16 and |1 of the arms I! and 12 respectively. The grab, illustrated in Figure 1, is of the socalled ice-tong type wherein the arms il and 12 are crossed and pivoted together at the point of crossing by apin 18.Link bars 19 and Z! are pivoted to the upper extendedends 2,! and of the arms Il and |2 bypins 23 and 24, respectively, and are brought together and pivoted to alift ring 25 by apin 26. The stock 93, gripped by the jaws |4 and |5, is lifted by a hoist (not shown) but which is adapted to be attached to thelift ring 25 in any desired manner. Upward pull upon thelift ring 25 will rock the arms ii and 12 about the common pivot pin E8 to cause these arms to move toward each other and the jaws is and [5 to securely grip the stock E3, whereby it may be lifted and transferred to another location.

The means shown in Figures 1 and 2, which is provided to lock the arms H and 12 and with them the jaws Id and |5 in open position, comprises a bar 21' pivo-ted at one end upon thepivot pin 23 and being provided at its other end with anelongated slot 28 in which an extended end of the pivot pin 2d is adapted to ride. One end of theslot 28 is enlarged to form astop shoulder 29 which when the arms are in open position drops in front of thepin 24 to retain thepins 23 and 24 in their farthest spread apart position and the arms II and i2 in open position. Theshoulder 3! formed by the other end of theslot 28 limits the closed position of the arms II and B2 to prevent the jaws Ili and I engaging, resulting in possible damage thereto. Thebar 21 is preferably extended beyond theslot 23 to form aconvenient handle 32 by which an operator may raise thebar 21 to release theshoulder 29 from thepin 24 to permit the jaws Id and I to swing toward each other togrip work 13 disposed therebetween.

Upon lowering the work I3 upon a support, continuing the lowerin-g of the grab, to cause the undersurface of the arms II and I2, directly below the pivot pin IB, to engage thework 13, will suhiciently spread thepivot pins 23 and 24 whereby thestop shoulder 29 will drop in front of thepin 24. If desired, stoplugs 33 and 34 may be provided on the arms I I and I2 in position to be engaged by the adjacent arm to limit the spread of the arms and to lprevent them being lowered beyond the desired amount. Requiring as it does the manual release of thecatch shoulder 29 from the pin 2A the arrangement shown in Figures l and 2 is Semi-automatic.

Figure 4 illustrates a full automatic form of means for releasably looking the arms II and IZ in open position. In this form aswingable catch member 35 having a rearwardly extendinghooked end 36 is pivotally secured to the link I9 with its hookedend 35 adapted to enter and ride in acam way 31 provided on theend 2| of the arms I2. Themember 35 is provided with anoffset portion 33 the weight of which acts on themember 35 to normally maintain it in an angular position in respect to the Vertical, as indicated in dotted lines in Figure 4, whereby thehooked end 38 of themember 35 will en-gage and ride down an inclined surface of a catch 39 and a block 4| into theentrance 42 of thecam way 31, when thepins 23 and 24 are spread apart by the lowering of the grab as above described, which action moves the link I9 toward thearm end 2|.

Upon attempting to again raise the grab the hookedend 3% swings under the block 4| and is caught in agroove 43 whereby the arms II and I2 will'be held in open position. When lowering the grab to pick up another stock IS, thehooked end 36 is moved downwardly and swings out of the groove Il3 into position to ride out of thecam way 31 through itsexit 44. Upon lcaving thecam way 31 the hookedend 35 raises the catch member 39 which is pivoted at f'l to the arm end 2 I, and drops back into place after the hookedend 36 leaves thecam way 31. The various positi-ons of thehooked end 36 in its travel into and out of thecam way 31 are indicated in dotted lines in Figure 4.

In gripping various sizes of stock I3, the jaws Id and I swing upon respective pivot pins QS and 41 by which they are secured to the arm end IEi and Il, and below the center of -gravity of the jaws M and I, will automatically adjust themselves to properly engage the stock to be gripped. In order that the jaws M and l will not swing toward each other, when the grab is lowered to release them from the stock E3, and again grip the stock when the grab is again raised in arm opened position, the means constituting one feature of this inventicn, is provided to maintain the jaws in the last position which they assumed in gripping the stock last acted upon by the grab.

The means herein shown for accomplishing the result of so maintaining the jaws in such position includes, see Figure 3, a cup-shaped button '"28 which is loosely disposed in an opening G9 provided in a side flange 5|, eXtendin-g from each jaw id and I into position to overlie a side surface of the arm end II and 12, and which button i is located above therespective pivot pins 46 and 111, which pins also pass through the flanges I. A threadedsleeve 52 secured to the flange I, preferably by welding, extends outwardly from the same and encloses a compression spring Et which reacts between thecupshaped button 43 and acover member 54, which is screw-threaded onto thesleeve 52, to press the button i against the respective arm end. By varying the position of the cover 5d on thesleeve 52, the tension lof thespring 53 may be adjusted. The jaws IQ and I are so positioned on the respective arm ends 2! and 22 as to be limited in their swinging inovement in respect thereto by being adapted to have their ends engage the respective arm end. The arrangement is such that the button (it will be prevented from riding off the arm end at eithei` side thereof, and therefore this jaw movement limiting stop means serves two useful purposes.

In this instance the jaws it and I are U- shaped in cross-section and have the other flange of this form extended over the other side of the arm end from that engaged by the button 138. Stock penetrating points are also shown as being provided and extend from the jaws I 'i and E5 to assist in gripping the stock I3. Thesepoints 55 are preferably of hardened steel and are screw-threaded into the respective jaw.

By the provision of the above doscrihed proved means to releasably retain the jaws open position and the means to mainta'ln the jaws in the last position assumed thereby when grippin-g the last stock acted upon. an immer/*ed grab structure is provided which is particulerly efcient in use. Such an improved grab is also much safer to use, can be readily manipulated, and is compact and relatively inexpensivc to manufacture.

While there has een described above :referred forms in which the features and pr' ples of this inventi-on are embodied it i ll lto understood that the same may be embooe` other specific forms without departing from spirit and essential attributes tliereof, and it therefore desired that the present errlr` i be considered in all respects llustrative and not restrictive, reference being had to the cl rather than to the foregoing description in cate the scope of the present invention.

Having thus fully disclosed the invention, t'h is claimed as new and for which it is desired secure Letters Patent is:

l. In a stock lifting grab, oppcsed arms adapted to move toward and away from each other, a stock engaging jaw pivoted to each arm to normally swing dcwnwardly when released from the stock by movement of the arms away from each other, and means carried by each jaw frictionally engaging the respective arm to resist swinging movernent of the jaw in respect to arm, and means to adjust the friction said arm swinging resisting means.

2. In a stock lifting grab, opposed arms adapted to move toward and away from each other, stock engaging jaw pivoted to each arm to nermally swing downwardly when released from the stock by movement of the arms away from each other, a spring pressed button carried by each jaw in position to frictionally engage the respective arm to resist swinging movement of the jaw in respect to the arm, and means to adjust the frictional tension of the button on the arm.

3. In a stock lifting -grab, opposed arms adapted to move toward and away from each other, a stock engagng jaw pivoted to each arm to normally swing' downwardly when released from the stock by movement of the arms away from each other, a button slidable in and carried by each jaw in position to engage the respective arm, a spring adapted to press each button toward the respective arm, and means to adjust the tension of each spring.

4. A grab for lifting stock comprising crcssed arms pivoted together at their crossing point, each of the ends of said arms at one side of their crossing point having stock engaging jaws pivoted thereto, each of the ends of said arms at the other side of their crossing point having an end of a link pivoted thereto by pivot pins, the other ends of said links being pivotally secured together, a bar pivoted at one end to one end of the arm and link ends by the pin thereat and having a slot embracing the pivot pin at the pivoted ends of the other arm and link, a stop shoulder formed in the bar end having the slot to engage the respective pivot pin in the slot to retain the jaws in spread apart position and another shoulder engageab-le by the pivot pin to limit the movement of the jaws toward each other.

5. A grab for lifting stock comprising crcssed arms pivoted together at their crossing point, each of the ends of said arms at one side of their crossing point having stock engaging jaws pivoted thereto, each of the ends of said arms at the other side of their crossing point having an end of a link pivoted thereto by pivot pins, the other ends of said links being pivotally secured together, a bar pivoted at one end to one of the arm and link ends by the pin thereat and having a slot embracing the pivot pin at the pivoted ends of the other arm and link, a stop shoulder formed in the bar end having the slot to engage the respective pivot pin in the slot to retain the jaws in spread apart position and another shoulder engageable by the pivot pin to limit the movement of the jaws toward each other, and means to resist swinging movement of each jaw on the respective arm.

6. A grab for lifting stock comprising crcssed arms pivoted together at their crossing point, each of the ends of said arms at one side of their crossing point having stock engaging jaws pivoted thereto, each of the ends of said arms at the other side of their crossing point having an end of a link pivoted thereto by pivot pins, the other ends of said link being pivotally secured together, a bar pivoted at one end to one of the arm and link ends by the pin thereat and having a slot embracing the pivot pin at the pivoted ends of the other arm and link a stop shoulder formed in the bar end having the slot to engage the respective pivot pin in the slot to retain the jaws in spread apart position and another shoulder engageable by the pivot pin to limit the movement of the jaws toward each other, each of said jaws being pivoted to the respective arm to normally swing downwardly when released from the stock by movement of the arms away from each other, and means carried by each jaw and frictionally engaging each arm to resist swinging movement of the jaw in respect to the arm.

7. A grab for lifting stock comprising crcssed arms pivoted together at their crossing point, each of the ends of said arms at one side of their crossing point having stock engaging jaws pivoted thereto, each of the ends of said arms at the other side of their crossing point having an end of a link pivoted thereto by pivot pins, the other ends of said links being pivotally secured together, a bar pivoted at one end to one of the arm and 1in k ends by the pin thereat and having a slot embracing the pivot pin at the pivoted ends of the other arm and link, a stop shoulder formed in the bar end having the slot to engage the respective pivot pin in the slot to retain the jaws in spread apart position and another shoulder engageable by the pivot pin to limit the movement of the jaws toward each other, each of said jaws being pivoted to the respective arm to normally swing downwardly when released from the stock by movement of the arms away from each other, and means carried by each jaw and frictionally engaging each arm to resist swinging movement of the jaw in respect to the arm, and means to adjust the friction of said arm swinging resisting means.

JACK BRESLAV.

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