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Publication numberUS2446610 A
Publication typeGrant
Publication dateAug 10, 1948
Filing dateAug 10, 1946
Priority dateAug 10, 1946
Publication numberUS 2446610 A, US 2446610A, US-A-2446610, US2446610 A, US2446610A
InventorsRenfroe Joseph C
Original AssigneeRenfroe Joseph C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Plate lifting clamp
US 2446610 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

1 J. c. RENFROE 2,446,610

PLATE LIFTING CLAMP Filed Aug. 10, 1946 2 Sheets-Sheet l INVENTOR.

B -A R. Wm.

Aug. 10, 1948.

PLATE LIFTING CLAMP Filed Aug. 10, 1946 2 Sheets-Sheet 2 7 INVENTOR. eYoXasp dfiasizf'rae J. c. RENFROE 2,446,610

Patented Aug. 10, 1948 -'2,446,610' i .PLATE IZIFTING; C AMP Joseph 0. Renfroe, Jacksonville,'-Fla. Application August 10, 1946, Serial No. 689,732:

' This invention relates to a new and improved I form of plate lifting clamps, and more especially to a resiliently tensioned manually operated pivotei jaw constructionfor said clamp.

flj' An object of the invention is to provide an 1' improved form of plate lifting clamp which will be formed with a vertically extending slot in its lower edge with a fixed plate engaging jaw in one side thereof, and a pivotally mounted toothed .camming jaw in the opposite side of said slot, the same being linked with a vertically adjustable clevis, and by means of a coil spring with apivoted jawlocking and releasing arm.

Another object of the invention is to provide I an improved plate lifting clamp for lifting heavy steel platesand the like, said clamp being formed withs'paced interconnected body members having a vertical slot extending upwardly 'into the said body members and'an aligned slot disposed above said first mentioned slot, together with a fixed plate engaging jaw secured in-one side, of said first mentioned slot,--and a pivoted toothed jaw mounted in the Opp ite side of said slot, the same being connected by means of a pair of links connected with the transversely extending pin slidably positioned inv the uppermost slot and se cured to the lower end of the clamp clevis, with .v the addedfeature of a jaw releasing lever con- Hnectedwithsaid pivoted jaw by means of a coil bottom of. said clamp body, together with a clevis and, a pivotally. mounted jaw releasing lever-conspring and a cross pin connected with saidlinks. ;A further object of the. invention is, to provide an improved form of steel plate lifting clamp havring -a fixed jaw and a pivoted jaw mounted at the opposite sides of a vertical slot formed in the V connected-with said pivoted jaw for operating; the same to effect a camming and locking engage- Y ment with aplate when positioned in said slot,

Ynected by means of a spring with the linkage connected between said pivoted jaw and clevis,

whereby said lever will be manually swung outi wardly away from the clamp body to release the hold of the pivoted jaw upon the plate, and by moving the lever inwardly past center, the pivoted jaw will be locked and the plate may not be released until the locking lever is deliberately and positively swung past center and away from the Another object of the invention is to provide 4 Claims (Cl. 294 104) an improved steel plate lifting clamp which will be highly efficlent'in operation, and relatively inexpensive to manufacture and produce. Other objects, 'wilIappear as the description proceeds; V I

In the 'accompanyingjdrawings which form a part'of the application,

' Figure 1 is a side elevation of the improve plate lifting clamp with a plate engaged and locked between its fixed and pivoted jaws;

Figure 2 is a similar view with one sidebody meriiber'removedto show the positioning of the various parts when in locked'position;

Figure 3 is a bottom'plan view of the improved plate lifting clamp;

Figure ,4 is a side elevation of the improved plate lifting clamp with a side body member "removed to show the positioning of the various j parts when in released or unlocked position;

" Figure 5 is a vertical sectional view taken on the line 5-'5 of Figure 2, and I J Figure 6 is a front'elevation of the concentrically'ribbed or toothed fixed jaw.

Like charactersof reference are used through out theflfollowing specification and the accompanying drawings to designate corresponding In carrying out the invention, there is provided an improved form of steel plate lifting clamp comprising a'pair of vspaced parallel extending body members I and 2, the same being connected together and held. in the proper spaced relation by means of the spacing collars 3 and 4 supported upon. the headed bolts 5 and i respecti'vely', arranged near the upper portion of the I clamp body.

A vertical slot 1 is formed in the lower edge of the clamp body approximately centrally of spaced body members I and 2.

'said body, one side of said slot 1 being formed by the connecting web 8 formed between the said The web 8"is aperturecl to receive the fixed jaw 9 which is formed with concentrically disposed ribs or teeth l0 and is supported in place by means of the headed rivet ll whose opposite end issplit as at I 2 and is upset in the countersunk bore 13in the opposite side of said web 8.

The vertical'slots I! are formed through the side members I and 2 in alignment with' the slot 1 in which the steel plates l5 are received,

and support the vertically adjustable cross 'pin I6 upon which the clamp clevis H is supported for vertical adjustment with said pin l5. An eye I8 is formed in the upper end of the clevis H for attachment to a hook upon a hoist line (not shown) An arcuate camming jaw l9 formed with the teeth 20 is ivotally supported upon the cross pivot pin 22 mounted between the body side plates l and 2, said pin being headed at 23 on one end, and transversely apertured at its other end to receive the cotter :pin or key 24. The end of the camming jaw is remote from the teeth 20 supports a large bearing pin 25 upon the outer ends of which theaqspaeedxonnectin links 26- and Zl are mou'ntds one at' either side of -the jawe and extending upwardly between the side body members I and 2 to be secured or mounted at either side of the clevis l'l upon the cross pin it. .An ear 28 is integrally formed on the outerportion of each of the lower ends of the=llnksi2lieands 21 and. are connected b means oithe pin 29 which supports the lower end of the coil tensioning and locking spring 30. -v The U-shaped jaw Vrleleasing and locking arm #3 l is;gpivotallyqmountedtupon the cross. -pln 32 disposed between :the-slderbodyrmembers l: and 2, and is iormed with :thetfingenengagingdirilflcat .-,-its.upper1 endfor operating athe same. ilThepin 34 is mounted between the sides of thelocking :2 arm 3 l atits iuppereend, and supports the upper end of the coil tensioning-tand lockingespringw 3.0. Astop-pin-iS is. connected between the sideimembers- Land-.2, andtlimits the .inwandmovement of the locking and releasingiarm 3 l ,t-whicheismoved past: center! tt -alocletthe .pivoted jaw in clamped positionregardless-gofethei positioniofc. theclevis, and regardless-of whether or. rnotn-the plataand eclampdsnsuspended ormntthe v ground.

From the foregoing descriptiom'itmiili heapgmarenteihat the inoderof prouted plate :lifting clampiisr as sfollows: vl'ihe clamp will loe supported.- byza x lzuopk' .(notshown) on the end ofiatrlifitingeable saidhookheing lens' fidothmngh; the eye ofsthet-lifting. clevis land the clamp will be jihesu shaaoedaiavw locking ande-neleasingntm' 3| which will move;tha gtoothed e-pivotedf iaw.r130. a :point, practical-1y withint the ,space;between ;"the

wparallel;rbod tmember's; and; 2 -,;laterallyt.'of the enotch ortslot 1.

the edge of a steel plate or other thine edged element by inser-tinguthe plateor element ,withe inzthe -sloty T aif-ter which 'theidoitil'iil ignarld ,Ie-

over;rdeadscenter thereby; locking .the pivoted ,tiawi-in camniingengagement with tne'side m the said ,plate or element, i ltowilllbe ;found'that n0 tmatterwhether the clevis is .atjthe ,tpppnbottom aof'its movementyvithirt the'slotsidi itiwillib impossible to accidentally or intentionally remove the clamp ,irommheplate without first; manually unca ing wI.the,globlsijag; nd releasingjelementwto its ;,nutei; nes t pofsition, thereby releasing the rpivotedqiaveto disengage*the same from'ithe'pljate 1 .40: element. r w If i IFrorn theforegbingfdesorii tion,jit .willn 3,p.. g-parent' .thatgthere .hasbeen 'Ldevised provided hiemyyeificientgimrm. of, plate, flitting 'c'larnp -;wne1j willbe positive in actiori'gto lock azplatepor ,blenientbetween'fits jaws, and which'will'also be necessary to deliberately releasefthejaw releas- .ingarm beforenthe pivoted 'iaw willbe enabled-to .release'; the, plate: from' between it "and fthefixed new. e w 'Q ,pperationgofw the; im-

newb e-pulling, outwardlyron' .Jl-he, iclamp .visithen placeds over aleasingrarmgilis pushed inwatdlyhuntil. it. passes While the preferred embodiment of the instant invention has been illustrated and described, it will be understood that it is not intended to limit 7 the scope of the invention thereto, as many minor changes in detail of construction may be resorted to without departure from the spirit of the invention.

Having thus described my invention what I .claim as new and desire to secure by Letters PatlO ent of the United States is:

1. A plate lifting clamp having spaced parallel interconnected side members, a connecting web between said members, said clamp being formed with a vertical plate receiving slot extending up- -y-wvaal'dly fromzits'loweriedge a fixed jaw supported l byfl saida'web; atcone sideQbf said Jslot, ;a, pivoted toothed camming jaw mounted at the opposite nside of said slot, said side members having opposed vertical slots formed through their upper g-ndsin alignment with said plate receiving slot,

t-sat ran y lt ely extending bearin pin slidably nrcunted in said slots, a clevis secured to said pin =-having=aineye in its upper end, connecting links pivotatly connected with said pin and with the outer end of said pivoted jaw, a jaw locking and releasing. arm pivoted between esaidnside. memhers) and 1a coilspring connected.betweenithe "lower ends or saidflinks andrto, a point on'the end ofsaid arm remote. iromiits'pivot. 2,15 plate ,liftingfcla'mp: having spaced parallel interconnected side members; a connecting web between" thefqlower' "ends: of" said; members j sald clamp being termed-"with a" vertical'pljatereceiving slot extending. upwardly from -its :loweredge, a. stationary jaw supportediy' ts'aidiwebrjat' one side: or said slot, a split' piri iorsecuring'said'jaw in p sitiom'isaid web beingcduntersunkrto protect -the splitjends" of'said pinifromfa'cbidental removal; a tocthed camrning'jaw pivoted-between saidsidelmembersattheqopposite side *o'fsa'idslot, said: side "memb ersihavingim posed -verticar slots "formed throughitheir upper "-e'nds in alignment with said-plate receivingslot; a; transverselymxtending bearingwin -adjustably mounted' between said slotsf a 'clevis'-'secured' to said pin- 'forined witha*hook receivi ng eye units upper "en'drconneeting' {linksbetweerr said sidemenabers pivotally connected with said bearing pin'-and:-with"the outer end -of said -pivoted jawra' Lf shapd jaw lockin gandreleasing armpivotally connected betweensaid sidemefiibersf a-;eoil spring connected jh'et'ween-f the 1owerends of said-"f'links and 'to a -point on the erid of -s'aid =arm" rernote fromtits i-pivot: and a stop pinebetweemsaidsidemembers disposedpast center wherr said" arm-- isin ldcked "position. r 1

1 3.-'-A 'p1ate lifting clamp oompri'sin'gspaied parallel interconnected "de meinbe'rg havingarrdn- -wardlv irectedfve ical plate reeei ving slot co r ifi fl r ed e, lw s u n ed i the upper end of saidelamp dn alignment with saidslrot for 'verticaram ustment,-' a -fi x'ed 'jaw in one-side o'fsaidfslottapivoted carmning ia'w dn 'the oppds'ite side *taid*slotylinkage conneotd between said jclevis' andsaidpivoted 'jaw; and a jaw lo cking and releasing arm pivotal ly attabh'ed *to said cIamp andwonneoted witlr said'fpivbted jaw fo1f'lcclting-the-iiaw in clamped positlon-wvhen said-amt ir'iovdpast dead center andfi fo re- 7 asing s'aidjaw when jsaid a rirr is moved in the theirlower ends, a clevis supportedtirtfthe npper end of said clarnp in aligmnent with said slot, a REFERENCES CITED removable fixed aw in one side of said slot, a plV- oted camming jaw in the other side of said slot, The following e c s a e of record in the linkage connected between said clevis and said file Of this P pivoted jaw, and a resiliently tensioned jaw locl z- 5 UNITED STATES PATENTS ing and releasing arm pivotally attached to said clamp and connected with said ivoted jaw for Number Najme Date locking the jaw in clamped position when said 1,514,933 Monmch 11, 1924 arm is moved past dead center and for releasin 2,360,601 WaldTuP 17, 1944 said jaw when said arm is moved in the opposite 10 2,370,411 Monaco 1945 direction.


Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1514983 *Jun 30, 1921Nov 11, 1924Monnich HenryHoisting clamp
US2360601 *Nov 15, 1943Oct 17, 1944Rodney S WaldrupPlate clamp
US2370411 *May 19, 1944Feb 27, 1945Monaco OtinoGrapple
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2549918 *Jun 26, 1945Apr 24, 1951Joseph G MillerSheet metal handling tool
US2618505 *May 31, 1951Nov 18, 1952Rosenbaum GadLifting clamp
US2654630 *May 27, 1952Oct 6, 1953Joseph C RenfroePlate lifting clamp
US2699172 *May 6, 1950Jan 11, 1955Fred ThurmerMachine for stripping hop vines
US2852300 *Apr 7, 1954Sep 16, 1958Merrill BrothersPositive grip lifting clamp with direct hand lock
US2986422 *Aug 12, 1959May 30, 1961Raymond L RenfrocPlate lifting clamp
US3074753 *Jul 21, 1960Jan 22, 1963Merrill BrothersLifting clamps and gripping pads therefor
US3189377 *May 21, 1962Jun 15, 1965Merrill BrothersSteel plate lifting clamps
US3249206 *Aug 14, 1962May 3, 1966Fmc CorpMachine for handling eggs
US3414315 *Oct 19, 1966Dec 3, 1968Renfroe & Sons J CLifting clamp
US3960264 *Jan 28, 1975Jun 1, 1976Burroughs CorporationItem transport apparatus
US4162804 *Feb 8, 1978Jul 31, 1979J. C. Renfroe And Sons, Inc.Lifting clamp
US6086126 *Oct 7, 1998Jul 11, 2000Systronic Maschinen GmbhGripper for flat components
US7928336Dec 7, 2005Apr 19, 2011Lockheed Martin CorporationClamp for mixed mail sorter
US8022329Dec 7, 2005Sep 20, 2011Lockheed Martin CorporationSystem and method for full escort mixed mail sorter using mail clamps
US8038106Oct 18, 2011Thomas & Betts International, Inc.Fast beam clamp
US8143548Jan 6, 2011Mar 27, 2012Lockheed Martin CorporationClamp for mixed mail sorter
US8326450Dec 7, 2005Dec 4, 2012Lockheed Martin CorporationMethod and system for GPS augmentation of mail carrier efficiency
US20060061112 *Jan 10, 2005Mar 23, 2006Yale Industrial Products GmbhLoad-carrying device
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US20080230449 *Dec 7, 2005Sep 25, 2008Stemmle Denis JSystem and Method for Full Escort Mixed Mail Sorter Using Mail Clamps
US20090005900 *Dec 7, 2005Jan 1, 2009Stemmle Denis JMethod and System for Gps Augmentation of Mail Carrier Efficiency
US20090139156 *Nov 25, 2008Jun 4, 2009Thomas & Betts International, IncFast beam clamp
US20110095154 *Jan 6, 2011Apr 28, 2011Lockheed Martin CorporationClamp for mixed mail sorter
USRE45825Oct 26, 2012Dec 22, 2015Thomas & Betts International LlcFast beam clamp
DE930113C *Mar 25, 1953Jul 11, 1955Merrill BrothersGreifvorrichtung fuer Stahlplatten
DE202005007218U1 *May 6, 2005Sep 21, 2006Pfeifer Holding Gmbh & Co. KgClamp for clamping and lifting loads has a clamping lever, a supporting lever and a safety element with an eccentric/wedge-shaped contour
EP0107848A1 *Oct 22, 1983May 9, 1984J.C. Renfroe and Sons, Inc.Lifting clamp locking mechanism with push button release handle
U.S. Classification294/104, 279/33
International ClassificationB66C1/42, B66C1/48
Cooperative ClassificationB66C1/48
European ClassificationB66C1/48