CA1115935A - Chain grab hook providing for a flat lay cross-over link - Google Patents
Chain grab hook providing for a flat lay cross-over linkInfo
- Publication number
- CA1115935A CA1115935A CA326,524A CA326524A CA1115935A CA 1115935 A CA1115935 A CA 1115935A CA 326524 A CA326524 A CA 326524A CA 1115935 A CA1115935 A CA 1115935A
- Authority
- CA
- Canada
- Prior art keywords
- hook
- chain
- bight
- throat
- shank
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 208000027697 autoimmune lymphoproliferative syndrome due to CTLA4 haploinsuffiency Diseases 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000010008 shearing Methods 0.000 description 2
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- AHLBNYSZXLDEJQ-FWEHEUNISA-N orlistat Chemical compound CCCCCCCCCCC[C@H](OC(=O)[C@H](CC(C)C)NC=O)C[C@@H]1OC(=O)[C@H]1CCCCCC AHLBNYSZXLDEJQ-FWEHEUNISA-N 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
- F16G17/00—Hooks as integral parts of chains
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B45/00—Hooks; Eyes
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Hooks, Suction Cups, And Attachment By Adhesive Means (AREA)
- Load-Engaging Elements For Cranes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention provides a chain grab hook for suspending a load, which comprises a hook body including a shank having an eye by means of which the hook- is suspended in vertical attitude, a bight integrally joined with said shank and a free end portion integrally joined with. said bight. The shank, bight and free end portion lie in a common plane generally forming a C-shape to define a throat. The free end portion has a substantially flat upwardly facing support surface defining the lower side of the throat and the free end portion has a generally vertically extending depression in its opposite sides whereby the support surface in plan view presents a widthwise elongate support surface portion at the innermost end of the throat and a narrowed portion of reduced width. The elongate surface portion supports the barrel portion of a chain link received in the throat and the width of the narrowed portion is such as to receive bight portions of adjacent chain links. The shank overlies the support surface to define the upper side of the throat and has down-wardly and laterally outwardly facing abutment surfaces on opposite sides thereof to engage the bight of one of the adjacent links to thereby force such bight also against an edge of the narrowed portion when the other of the adjacent links has a load suspended therefrom. The depressions are laterally offset from the eye whereby the hook is both rotated in its vertical plane and tilted to one side relative there to when the chain supports a load.
The invention provides a chain grab hook for suspending a load, which comprises a hook body including a shank having an eye by means of which the hook- is suspended in vertical attitude, a bight integrally joined with said shank and a free end portion integrally joined with. said bight. The shank, bight and free end portion lie in a common plane generally forming a C-shape to define a throat. The free end portion has a substantially flat upwardly facing support surface defining the lower side of the throat and the free end portion has a generally vertically extending depression in its opposite sides whereby the support surface in plan view presents a widthwise elongate support surface portion at the innermost end of the throat and a narrowed portion of reduced width. The elongate surface portion supports the barrel portion of a chain link received in the throat and the width of the narrowed portion is such as to receive bight portions of adjacent chain links. The shank overlies the support surface to define the upper side of the throat and has down-wardly and laterally outwardly facing abutment surfaces on opposite sides thereof to engage the bight of one of the adjacent links to thereby force such bight also against an edge of the narrowed portion when the other of the adjacent links has a load suspended therefrom. The depressions are laterally offset from the eye whereby the hook is both rotated in its vertical plane and tilted to one side relative there to when the chain supports a load.
Description
CHAIN GRAB ~OOK PROVIDING FQR
A F~AT LAY CROSS-OVER LINK
TECHNICAL EIELD OF THE INVENTION
The present invention relates to chain grab hooks.
More Specifically; the invention relates to a specific chain grab hook which holds the engaged chain cross-over link in ~. a generally flat or horizontal position.
: ~ 5 BACKGROUND OF THE INVENTION
Chain grab hooks grab a chain in such a way that the chain is preve~ted from running through the hook. To accom-plish this end, the throat of the hook, defined by the shank portion at one side, the free-end portion at khe other side, ` and an inte~mediate connecting bigh~ portion, is made large ; enough to recaive one link in an upright cross-over orienta-: tion but small enough to prevent passage there~hrouqh of an adjacent link. ~he upright cross-over link rests edgewise on the bridging bight por~ion at the lower end o the ~hroat.
With presently constructed grab hooks, the chain, when placed under loaded conditions, is subjected ~o combined stresses which, when large ~nough, ultima~ely cause the chain ~0 to ~ail. One of the stresses to which the chain is subjected i~ a tensile stress acting long.i~udinally of the chain. Chains are constructed to withstand such tensile stresses so that no problem is presented. When a chain link is seated in an up-right or edgewise position in the throat of the grab hook to rest on the lower bight portion however~ the cross over link
A F~AT LAY CROSS-OVER LINK
TECHNICAL EIELD OF THE INVENTION
The present invention relates to chain grab hooks.
More Specifically; the invention relates to a specific chain grab hook which holds the engaged chain cross-over link in ~. a generally flat or horizontal position.
: ~ 5 BACKGROUND OF THE INVENTION
Chain grab hooks grab a chain in such a way that the chain is preve~ted from running through the hook. To accom-plish this end, the throat of the hook, defined by the shank portion at one side, the free-end portion at khe other side, ` and an inte~mediate connecting bigh~ portion, is made large ; enough to recaive one link in an upright cross-over orienta-: tion but small enough to prevent passage there~hrouqh of an adjacent link. ~he upright cross-over link rests edgewise on the bridging bight por~ion at the lower end o the ~hroat.
With presently constructed grab hooks, the chain, when placed under loaded conditions, is subjected ~o combined stresses which, when large ~nough, ultima~ely cause the chain ~0 to ~ail. One of the stresses to which the chain is subjected i~ a tensile stress acting long.i~udinally of the chain. Chains are constructed to withstand such tensile stresses so that no problem is presented. When a chain link is seated in an up-right or edgewise position in the throat of the grab hook to rest on the lower bight portion however~ the cross over link
- 2 -. is also subjected to a shearing or cut-tlng ~rce~ A chain link is not ordinarily designed to withstand such a shearing force acting transversely of the link. ~ccordingly, when a chain is used in conjunction with a gra~ hook, the breaking S strength of the upright link within the throat of the hook is reduced so that, when overloaded, the chain invariably breaks at this point. I~ is therefare often necessary to use larger chai.ns than are required to lift a desired load in order to assure an acceptable margin o safety. This, in turn, cause~ increased expense and inconvenience to the users of the chain.
In addition ~o possible chain failure, the hook isalso subject to failure under either overload conditions or conditions of cyclic fatigue. Both the overload failure value and the fatigue life of a part are detrimentally effected by high stress concentration~ as opposed to a more uniform over-all stress distribution. A chain grab hook having ~ verti-cally oriented slot for receiving the cro~s-over link produces very high localized stress concentrations in the hook since the cross-over link is vPr~ically supported by the hook in a very limited area of the saddle or bight portion of the hook.
In many hook designs, ~he cross-over link, under the influ-ence of the load, pivots at one side of the hook to lift off of téh support saddle along most o its length with the result o being supported by an even smaller area of ~he hook. In order to prevent early hook failure, conventional hooks have o nece~sity been fabrica~ed with excessive quanti~ies of material and/or have ~een given a relatively low maximum load limit.
Accidental disengagement of the chain from conven-kional chain gra~ hook also presents a hazzard. In an un-loaded or slack condition, it is possible for the cross-over link of the engaqed chain to ~lide out o the engaging hook in a manner which either completely disengages the chain from 35 the hook or removes the cro~s-over link to a position which ~5~
-- 3 ~
would cause either chain or hook damage if the loaded colldi-tion were to be resumed.
THE INVENTION
The present invention relates to an improved chain grab hook wherein improved stress di.stribution characteristics in both the hook itself and the engaged chain are achieved;
wherein improved safety by -the prevention of accidental chain fallout is achieved; and wherein a reduction in hook reach is achieved thereby minimizing the quantity of material needed : for fabrication of the hook.
The chain grah hook of the present invention is basically characterized by the fact that the shank~ free-end, and bight portion of the hook are configured to grab the chain in a manner which supports the cross--over link of the engaged chain in a flat attitude forming an angle with the horizontal no greater than 45. This "flat lay" is particularly advan-tageous in that both legs or barrels of the chain link are ~ 20 supported by and rest on an upwardly facing supporting sur-: - face of the free-end of the generally C-shaped hook. Such : support avoias stress concentrations and the bending forces experienced by both the hook and the cross-over chain link.
The extended.support surface provided for this "flat lay"
~ 25 link has a dimension substantiall.y equal to the length of the : cross-over link. Recesses in the side of the free-end por-tion of the hook are provided to receive therein a portion o each of the side downstanding links joined to the cross-over link of the engaged chain.
The tip of the free-end portion is upwardly turned to~ard the shank portlon of the hook in order to provide an : obstruction to accidental removal of the cross-over llnk.
This upwardly turned tip cooperates ~ith the erlgagement of the downstandiny side links in the side recesses to virtually el.iminate accidental d.isengagement of the chain from the hook.
-`,`i~
~.
- ~ -The support surface of ~he free-end L~ortion ma~ be inclined to the horizontal by an angle of up to 45. Accord-ingly, the cross-over link of the engaged chain is also tilted from the horizontal so that its joined side links have a ten-dency to rotate back toward the body of the hook. This ten-dency to rotate or slide toward the body of the hook minimizes the distance between the load axis of the loaded chain and the neutral fibre axis of the hook to thereby minimize the t,ending moment placed on the hook.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention rnay be better Inderstood and its numerous objects and advantages will become apparent to lS those skilled in the art by reerence to the accompanying drawings wherein like reference nurnerals refer to like ele-ments in the several figures and in which:
Figure 1 i.s an elevational side view of the pre--erred embodiment of the present invention showing the hook in its loaded condition;
Fig~re 2 is a vertical cross-section of the loaded hook of figure 1 taken along the view lines 2-2; and Figure 3 is a cross-section of the hook of figure : 1 taken along view lines 3-3.
DESCRIPTION OF THE BEST MODE OF THE INVENTION
While the invention is susceptible of various mod-i~ications and alternative constructions, there is shown in the drawlngs and there ~ill hereinafter be described, in de-kail, a description of the preferred embodirnent o~ the inven-t.ion. It is to be understood, however, that the specific description and drawings are not intended to limit the inven-tion to the specific form disclosed. On the contrary, it is intended that the scope of this paten-t include all modifications , ~;
.,,~ .
- s and alternative cons~ructions ~hereof ~alli~ it~in ~he spirit and scope of the invention as express2d in tlle al~L~en-ded claims to the full range of their equivalents.
The preferred embodiment of the chain grab hook 10 of the present invention, as illustrated in -the figures, con-sists of a shank 1~, a free-end 14 and a connecting bight 16, all of which lie in the same plane and which toqether generally 'form a C-shape. Shank 12, free-end 14 and bight 16 define therebetween a slot or throat 18 adapted to receive therein a traversing or cross-over link 30 of an engaged load c~rrying chain 20 of the bent wire link type. Shank portion 12 is pro-vided with a hook eye 38 ~or connecting the hook to a chain 28.
Free-end portion 14 includes a generally upwardly facing surface 40 which is the primary bearing surface for supporting ~he cross-over link 30 in a generally flat atti~ude.
The figures show that support surface 40 lies gen-erally in a plane which is tilted from the horizontal by a given angle in the plane of the hook when the hook is loaded.
Inclining support surface 40 and therefore link 30 to the horizontal, as shown in figure 1, causes the downstanding lateral links 3Z and 36 joined to the cross-over link 30 of the engaged load chain 20 to swing in the downhill direction.
This tendency to swing or rotate toward the bight 16 and away rom the central longitudinal axis 34 of link 30 ~see figure 3) as well as away from the hook axis 24 causes the load line 22 of tlle chain 20 to be moved closer to the neu-tral "~iber" 26 of the hook whereby the bending moment placed on the hook by the tensioned chain 20 is reduced.
When the hook 10 of the invention ;s loaded with a load bearing chain 20 as shown in figure 1, the slot or throat 18 lies with a generally horizontal attitude so that free-end portion 14 of the hook and i-ts upwardly facing surface 40 de-fine the bottom of the throat 18. With this attitude, link 30 is supported, a~ shown, in a genérally horizontal attitude so that surface 40 provides vertical support to both of the opposite legs or barrel sections 44, 46 of lin~ 30 Isee figure 3). In order to provide the greatest de~l^ee of sup-port so that stress concentrat;ons are minimized, surface 40 i5 formed to have a width across the plane of the hook substantially equal to the length of one of the barrel S~?C-tions of the link cross-over link 30, which is virtuall~ the entire length of the lin~ itself. While it is ~)referred to support both barrels 44, 46 along substantially their entire lengths, it should be understood that the scope of the in-vention is broad enough to include supporting link 30 sub-stantially along the entire length of only one barrel ~hile supporting the other barrel over a significantly reduced surface. It is also conceivable, although less desira~le, to provide a flat lay without supporting either barrel along its entire length.
As wil7 be recognized, as the angle of incline to the horizontal is increased, more or the load o~ chain 20 is shifted to the "inside" barrel 46 of link 30. One of the major advantages of distributing the load over increased areas of both link 30 and hook surface 40 of the invention will be los~, therefore, if the angle of incl;ne to the llor-izontal is too large. An angle of incline no more than 45 from the horizontal provides a generally "flat" attltude for cross-over link 30 while still deriving the support benefits inheren~ in the "flat" lay. On the other hand, angles of incline greater than 45 place the cross-over link in a gen~
erally "upstanding" attitude rather than in the desirable "flat" attitude of the invention and such a hook-chain syst:em would thus lack the added suppor~ advan~ages o~ the present invention~
I,ooking specifically a-t figure 1, a preferred hook design in which surface 40 is slightly angled to the horizon-tal before loading the hook is shown. After the hook has been engaged by a chain 20 and loaded, a~ shown, the hook has rotated under the influence of ~le load in the clockwise 5f~
7 _ , .direction to shift load line 2~ of the cl~ail~ to~.ird ~ 16 as a result of ~he previously described swingin~.l of sidc~ li.nk 32. The hook l0 is shown in its loaded, static con~lition in which the angle between surface 40 and the horizontal is approximately 15~. While the angle has been selected as ~hat which is preferred, it should be recognized that ot}ler angles may be selected and may result de~ending on engineering design and on the balance of the hook. Nevertheless, the ~resellt in-vention is intended to include hook designs which result in ~s much as a 45 incline of suppor-t surface 40 to the hori-zontal when the hook has been loaded. It is felt that al~gles greater than 45 diminish the ability of support surface 40 to support both opposite barrel sections of cross-over l.ink 30 to a degree tha-t renders such greater angles undesiraLle.
As has been described, it is desirable to forln free-end 14 and support surface 40 so that the support surface has : a dirnension perpendicular to the plane of the hook which, in at least one location, is at least as long as one of the barrel sections 44 or 46 of the cross-over link 30. One way of accomplishing this desirable end without interfering with the attitude of the side downstanding links 32 and 36, is to form hook 10 with a relatively hefty free-end ~ortiot~ 14 and to provide longitudinally extending depressions 42 in the sides of the free-end 14 for receiving therein one barre:l section of the side links 32, 36. Longitudinally e~tending ~epression 42 may be formed generally parallel to the vertical so as not to interfere with the tendency of links 32 and 36 to freely assume an orientation in line with the ~orce of gravity or the depression may be formed to extend generally parallel to the unloaded ax.is 24 or or:iented to ex-tend at an ;ntermediate angle.
Grooves 42 therefore permi~ each barr~l section o~
link 30 to be supported in a vertical direction substantially over their entire lengths without undue interference between the side link 32 or 36 and the body of the hook. Since link ~5~
30 is vertically su~ ol le(l alor~g vir-tuall~ iL:s e~l~ ire Ic~ tll, and si.de link 32 is permitted to penetrate int~ ~ OV~ 4~, there is very little if any tendency for link 30 t~ roc~ up away from the support surface 40 as is the tendenc~ in m~ny prior known chain hooks, Accordingly, chain link 30 is supported by upwardly facing sur~ace 40 substantially alollg the entire length of both barrel.sections 44, ~6 of the cross-over link 30, thereby distributinq the .I~ d ~:itroiJlh out the length of the link and over a signific3nt cont.lc~
area of the hook lO. Both chain 20 and hook lO are therei'ore less likely to fail under heavy loads and under accumul.3ted cyclic stresses.
As best seen in figure 1, free-end portion 14 n;ay include an upwardly turned tip 48 which cooperates with the configuration of shank 12 in order to form a two~part t~lroat 18 having a mouth part and a cross-over link engaging part.
The mouth part as shown is angled relative to the cross-over link engaging part so that removal. o~ the cross-over link 30 from -throat 18 requires that cross-over link 30 be twisted as it is removed from the throat~ Tip 48 then ~cts as an obstr~ction to the removal of the cross-o~7er link-from tlle chain grab hook lO and lessens the ~robability oE unint.~n-tional disengagement of the chain 2n from the hook lO.
Grooves 42 formed in free-end portion 14 also act to lessen the chance of acciden~al removal of the chain from the hook. Side links 32 and 36 seat themselves within grooves 42 so that grooves 42 limit their o~ltward movement with khe result that they may not be accidentally slid in the chain disengaging directi,on. Disengagemellt of chain 20 from the chain grab hook lO is easily manually accomplished, however, by concurrently lifting lateral links 36 and 32 to align their axes generally w.ith -the axis of cross-over link 30, sliding cross--over link 30 outwardly along the slo-t 18 while simultaneously :rotating link 30 to avoid the projecting tip 48. This complicated disengagement rnotion is one which can e~sily b~ aLcomplisl)ed l~y a ~or~.man who;~ intet-lt~o~ l5 t.o remove the chain from the l100~. However, the ~ ge~r~ t.
motion is so complicated that the probability of its acci-dcntal occurence is very slight even if the chain hook ln were to be tumbled end-over-end or held upside down. Chai.n hook 10 of the presen-t invention therefore is sigllificant.ly s~fer than prior known chain grab hoo~s.
In addition ~o possible chain failure, the hook isalso subject to failure under either overload conditions or conditions of cyclic fatigue. Both the overload failure value and the fatigue life of a part are detrimentally effected by high stress concentration~ as opposed to a more uniform over-all stress distribution. A chain grab hook having ~ verti-cally oriented slot for receiving the cro~s-over link produces very high localized stress concentrations in the hook since the cross-over link is vPr~ically supported by the hook in a very limited area of the saddle or bight portion of the hook.
In many hook designs, ~he cross-over link, under the influ-ence of the load, pivots at one side of the hook to lift off of téh support saddle along most o its length with the result o being supported by an even smaller area of ~he hook. In order to prevent early hook failure, conventional hooks have o nece~sity been fabrica~ed with excessive quanti~ies of material and/or have ~een given a relatively low maximum load limit.
Accidental disengagement of the chain from conven-kional chain gra~ hook also presents a hazzard. In an un-loaded or slack condition, it is possible for the cross-over link of the engaqed chain to ~lide out o the engaging hook in a manner which either completely disengages the chain from 35 the hook or removes the cro~s-over link to a position which ~5~
-- 3 ~
would cause either chain or hook damage if the loaded colldi-tion were to be resumed.
THE INVENTION
The present invention relates to an improved chain grab hook wherein improved stress di.stribution characteristics in both the hook itself and the engaged chain are achieved;
wherein improved safety by -the prevention of accidental chain fallout is achieved; and wherein a reduction in hook reach is achieved thereby minimizing the quantity of material needed : for fabrication of the hook.
The chain grah hook of the present invention is basically characterized by the fact that the shank~ free-end, and bight portion of the hook are configured to grab the chain in a manner which supports the cross--over link of the engaged chain in a flat attitude forming an angle with the horizontal no greater than 45. This "flat lay" is particularly advan-tageous in that both legs or barrels of the chain link are ~ 20 supported by and rest on an upwardly facing supporting sur-: - face of the free-end of the generally C-shaped hook. Such : support avoias stress concentrations and the bending forces experienced by both the hook and the cross-over chain link.
The extended.support surface provided for this "flat lay"
~ 25 link has a dimension substantiall.y equal to the length of the : cross-over link. Recesses in the side of the free-end por-tion of the hook are provided to receive therein a portion o each of the side downstanding links joined to the cross-over link of the engaged chain.
The tip of the free-end portion is upwardly turned to~ard the shank portlon of the hook in order to provide an : obstruction to accidental removal of the cross-over llnk.
This upwardly turned tip cooperates ~ith the erlgagement of the downstandiny side links in the side recesses to virtually el.iminate accidental d.isengagement of the chain from the hook.
-`,`i~
~.
- ~ -The support surface of ~he free-end L~ortion ma~ be inclined to the horizontal by an angle of up to 45. Accord-ingly, the cross-over link of the engaged chain is also tilted from the horizontal so that its joined side links have a ten-dency to rotate back toward the body of the hook. This ten-dency to rotate or slide toward the body of the hook minimizes the distance between the load axis of the loaded chain and the neutral fibre axis of the hook to thereby minimize the t,ending moment placed on the hook.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention rnay be better Inderstood and its numerous objects and advantages will become apparent to lS those skilled in the art by reerence to the accompanying drawings wherein like reference nurnerals refer to like ele-ments in the several figures and in which:
Figure 1 i.s an elevational side view of the pre--erred embodiment of the present invention showing the hook in its loaded condition;
Fig~re 2 is a vertical cross-section of the loaded hook of figure 1 taken along the view lines 2-2; and Figure 3 is a cross-section of the hook of figure : 1 taken along view lines 3-3.
DESCRIPTION OF THE BEST MODE OF THE INVENTION
While the invention is susceptible of various mod-i~ications and alternative constructions, there is shown in the drawlngs and there ~ill hereinafter be described, in de-kail, a description of the preferred embodirnent o~ the inven-t.ion. It is to be understood, however, that the specific description and drawings are not intended to limit the inven-tion to the specific form disclosed. On the contrary, it is intended that the scope of this paten-t include all modifications , ~;
.,,~ .
- s and alternative cons~ructions ~hereof ~alli~ it~in ~he spirit and scope of the invention as express2d in tlle al~L~en-ded claims to the full range of their equivalents.
The preferred embodiment of the chain grab hook 10 of the present invention, as illustrated in -the figures, con-sists of a shank 1~, a free-end 14 and a connecting bight 16, all of which lie in the same plane and which toqether generally 'form a C-shape. Shank 12, free-end 14 and bight 16 define therebetween a slot or throat 18 adapted to receive therein a traversing or cross-over link 30 of an engaged load c~rrying chain 20 of the bent wire link type. Shank portion 12 is pro-vided with a hook eye 38 ~or connecting the hook to a chain 28.
Free-end portion 14 includes a generally upwardly facing surface 40 which is the primary bearing surface for supporting ~he cross-over link 30 in a generally flat atti~ude.
The figures show that support surface 40 lies gen-erally in a plane which is tilted from the horizontal by a given angle in the plane of the hook when the hook is loaded.
Inclining support surface 40 and therefore link 30 to the horizontal, as shown in figure 1, causes the downstanding lateral links 3Z and 36 joined to the cross-over link 30 of the engaged load chain 20 to swing in the downhill direction.
This tendency to swing or rotate toward the bight 16 and away rom the central longitudinal axis 34 of link 30 ~see figure 3) as well as away from the hook axis 24 causes the load line 22 of tlle chain 20 to be moved closer to the neu-tral "~iber" 26 of the hook whereby the bending moment placed on the hook by the tensioned chain 20 is reduced.
When the hook 10 of the invention ;s loaded with a load bearing chain 20 as shown in figure 1, the slot or throat 18 lies with a generally horizontal attitude so that free-end portion 14 of the hook and i-ts upwardly facing surface 40 de-fine the bottom of the throat 18. With this attitude, link 30 is supported, a~ shown, in a genérally horizontal attitude so that surface 40 provides vertical support to both of the opposite legs or barrel sections 44, 46 of lin~ 30 Isee figure 3). In order to provide the greatest de~l^ee of sup-port so that stress concentrat;ons are minimized, surface 40 i5 formed to have a width across the plane of the hook substantially equal to the length of one of the barrel S~?C-tions of the link cross-over link 30, which is virtuall~ the entire length of the lin~ itself. While it is ~)referred to support both barrels 44, 46 along substantially their entire lengths, it should be understood that the scope of the in-vention is broad enough to include supporting link 30 sub-stantially along the entire length of only one barrel ~hile supporting the other barrel over a significantly reduced surface. It is also conceivable, although less desira~le, to provide a flat lay without supporting either barrel along its entire length.
As wil7 be recognized, as the angle of incline to the horizontal is increased, more or the load o~ chain 20 is shifted to the "inside" barrel 46 of link 30. One of the major advantages of distributing the load over increased areas of both link 30 and hook surface 40 of the invention will be los~, therefore, if the angle of incl;ne to the llor-izontal is too large. An angle of incline no more than 45 from the horizontal provides a generally "flat" attltude for cross-over link 30 while still deriving the support benefits inheren~ in the "flat" lay. On the other hand, angles of incline greater than 45 place the cross-over link in a gen~
erally "upstanding" attitude rather than in the desirable "flat" attitude of the invention and such a hook-chain syst:em would thus lack the added suppor~ advan~ages o~ the present invention~
I,ooking specifically a-t figure 1, a preferred hook design in which surface 40 is slightly angled to the horizon-tal before loading the hook is shown. After the hook has been engaged by a chain 20 and loaded, a~ shown, the hook has rotated under the influence of ~le load in the clockwise 5f~
7 _ , .direction to shift load line 2~ of the cl~ail~ to~.ird ~ 16 as a result of ~he previously described swingin~.l of sidc~ li.nk 32. The hook l0 is shown in its loaded, static con~lition in which the angle between surface 40 and the horizontal is approximately 15~. While the angle has been selected as ~hat which is preferred, it should be recognized that ot}ler angles may be selected and may result de~ending on engineering design and on the balance of the hook. Nevertheless, the ~resellt in-vention is intended to include hook designs which result in ~s much as a 45 incline of suppor-t surface 40 to the hori-zontal when the hook has been loaded. It is felt that al~gles greater than 45 diminish the ability of support surface 40 to support both opposite barrel sections of cross-over l.ink 30 to a degree tha-t renders such greater angles undesiraLle.
As has been described, it is desirable to forln free-end 14 and support surface 40 so that the support surface has : a dirnension perpendicular to the plane of the hook which, in at least one location, is at least as long as one of the barrel sections 44 or 46 of the cross-over link 30. One way of accomplishing this desirable end without interfering with the attitude of the side downstanding links 32 and 36, is to form hook 10 with a relatively hefty free-end ~ortiot~ 14 and to provide longitudinally extending depressions 42 in the sides of the free-end 14 for receiving therein one barre:l section of the side links 32, 36. Longitudinally e~tending ~epression 42 may be formed generally parallel to the vertical so as not to interfere with the tendency of links 32 and 36 to freely assume an orientation in line with the ~orce of gravity or the depression may be formed to extend generally parallel to the unloaded ax.is 24 or or:iented to ex-tend at an ;ntermediate angle.
Grooves 42 therefore permi~ each barr~l section o~
link 30 to be supported in a vertical direction substantially over their entire lengths without undue interference between the side link 32 or 36 and the body of the hook. Since link ~5~
30 is vertically su~ ol le(l alor~g vir-tuall~ iL:s e~l~ ire Ic~ tll, and si.de link 32 is permitted to penetrate int~ ~ OV~ 4~, there is very little if any tendency for link 30 t~ roc~ up away from the support surface 40 as is the tendenc~ in m~ny prior known chain hooks, Accordingly, chain link 30 is supported by upwardly facing sur~ace 40 substantially alollg the entire length of both barrel.sections 44, ~6 of the cross-over link 30, thereby distributinq the .I~ d ~:itroiJlh out the length of the link and over a signific3nt cont.lc~
area of the hook lO. Both chain 20 and hook lO are therei'ore less likely to fail under heavy loads and under accumul.3ted cyclic stresses.
As best seen in figure 1, free-end portion 14 n;ay include an upwardly turned tip 48 which cooperates with the configuration of shank 12 in order to form a two~part t~lroat 18 having a mouth part and a cross-over link engaging part.
The mouth part as shown is angled relative to the cross-over link engaging part so that removal. o~ the cross-over link 30 from -throat 18 requires that cross-over link 30 be twisted as it is removed from the throat~ Tip 48 then ~cts as an obstr~ction to the removal of the cross-o~7er link-from tlle chain grab hook lO and lessens the ~robability oE unint.~n-tional disengagement of the chain 2n from the hook lO.
Grooves 42 formed in free-end portion 14 also act to lessen the chance of acciden~al removal of the chain from the hook. Side links 32 and 36 seat themselves within grooves 42 so that grooves 42 limit their o~ltward movement with khe result that they may not be accidentally slid in the chain disengaging directi,on. Disengagemellt of chain 20 from the chain grab hook lO is easily manually accomplished, however, by concurrently lifting lateral links 36 and 32 to align their axes generally w.ith -the axis of cross-over link 30, sliding cross--over link 30 outwardly along the slo-t 18 while simultaneously :rotating link 30 to avoid the projecting tip 48. This complicated disengagement rnotion is one which can e~sily b~ aLcomplisl)ed l~y a ~or~.man who;~ intet-lt~o~ l5 t.o remove the chain from the l100~. However, the ~ ge~r~ t.
motion is so complicated that the probability of its acci-dcntal occurence is very slight even if the chain hook ln were to be tumbled end-over-end or held upside down. Chai.n hook 10 of the presen-t invention therefore is sigllificant.ly s~fer than prior known chain grab hoo~s.
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A chain grab hook for suspending a load, which comprises:
a hook body including a shank having an eye by means of which the hook is suspended in vertical attitude, a bight integrally joined with said shank and a free end portion integrally joined with said bight; said shank, bight and free end portion lying in a common plane generally forming a C-shape to define a throat;
said free end portion having a substantially flat upwardly facing support surface defining the lower side of said throat and said free end portion having generally vertically extending depression in its opposite sides whereby said support surface in plan view presents a widthwise elongate support surface portion at the innermost end of said throat and a narrowed portion of reduced width, said elongate surface portion supporting the barrel portion of a chain link received in said throat and the width of said narrowed portion being such as to receive bight portions of adjacent chain links;
said shank overlying said support surface to define the upper side of said throat and having downwardly and laterally outwardly facing abutment surfaces on opposite sides thereof to engage the bight of one of said adjacent links to thereby force such bight also against an edge of said narrowed portion when the other of said adjacent links has a load suspended therefrom; and said depressions being laterally offset from said eye whereby the hook is both rotated in its vertical plane and tilted to one side relative thereto when the chain supports a load.
a hook body including a shank having an eye by means of which the hook is suspended in vertical attitude, a bight integrally joined with said shank and a free end portion integrally joined with said bight; said shank, bight and free end portion lying in a common plane generally forming a C-shape to define a throat;
said free end portion having a substantially flat upwardly facing support surface defining the lower side of said throat and said free end portion having generally vertically extending depression in its opposite sides whereby said support surface in plan view presents a widthwise elongate support surface portion at the innermost end of said throat and a narrowed portion of reduced width, said elongate surface portion supporting the barrel portion of a chain link received in said throat and the width of said narrowed portion being such as to receive bight portions of adjacent chain links;
said shank overlying said support surface to define the upper side of said throat and having downwardly and laterally outwardly facing abutment surfaces on opposite sides thereof to engage the bight of one of said adjacent links to thereby force such bight also against an edge of said narrowed portion when the other of said adjacent links has a load suspended therefrom; and said depressions being laterally offset from said eye whereby the hook is both rotated in its vertical plane and tilted to one side relative thereto when the chain supports a load.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US90114278A | 1978-04-28 | 1978-04-28 | |
| US901,142 | 1978-04-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1115935A true CA1115935A (en) | 1982-01-12 |
Family
ID=25413654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA326,524A Expired CA1115935A (en) | 1978-04-28 | 1979-04-27 | Chain grab hook providing for a flat lay cross-over link |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5516890A (en) |
| AU (1) | AU4647279A (en) |
| CA (1) | CA1115935A (en) |
| DE (1) | DE2916849A1 (en) |
| FR (1) | FR2424222A1 (en) |
| GB (1) | GB2021678B (en) |
| IT (1) | IT7922285A0 (en) |
| SE (1) | SE7903616L (en) |
| ZA (1) | ZA791927B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6075203U (en) * | 1983-10-26 | 1985-05-27 | 株式会社石田衡器製作所 | Bag making and packaging machine |
| US8100449B2 (en) | 2010-03-15 | 2012-01-24 | Wray Christopher T | Chain grab hook with rotatable spring-loaded lock ball and snap-on nodule |
| USD778144S1 (en) | 2015-10-27 | 2017-02-07 | Apex Brands, Inc. | Cradle grab hook |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1494289A (en) * | 1920-03-17 | 1924-05-13 | Cleveland Chain And Mfg Compan | Connecting device |
| GB1135182A (en) * | 1964-09-18 | 1968-12-04 | Marshall Fisher Barnes | Improvements in, or relating to, chain slings |
| AT313656B (en) * | 1972-03-01 | 1974-02-25 | Pengg Walenta Ketten | Chain hook |
| GB1480124A (en) * | 1975-01-21 | 1977-07-20 | Albright H | Coin slot device |
| US4070823A (en) * | 1976-07-06 | 1978-01-31 | Columbus Mckinnon Corporation | Chain hook |
| DE2633092A1 (en) * | 1976-07-20 | 1978-02-02 | Rud Ketten Rieger & Dietz | SHORTING HOOKS FOR ROUND LINK CHAINS |
| SE421118B (en) * | 1977-04-20 | 1981-11-30 | Bergs Smide Ab K A | FOR CONNECTING TO A CHAIN DESIGNED GRIP HOOK |
-
1979
- 1979-04-23 ZA ZA791927A patent/ZA791927B/en unknown
- 1979-04-24 SE SE7903616A patent/SE7903616L/en not_active Application Discontinuation
- 1979-04-25 GB GB7914438A patent/GB2021678B/en not_active Expired
- 1979-04-26 FR FR7910642A patent/FR2424222A1/en not_active Withdrawn
- 1979-04-26 DE DE19792916849 patent/DE2916849A1/en not_active Withdrawn
- 1979-04-26 AU AU46472/79A patent/AU4647279A/en not_active Abandoned
- 1979-04-27 JP JP5243279A patent/JPS5516890A/en active Pending
- 1979-04-27 CA CA326,524A patent/CA1115935A/en not_active Expired
- 1979-04-30 IT IT7922285A patent/IT7922285A0/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| IT7922285A0 (en) | 1979-04-30 |
| GB2021678B (en) | 1982-06-16 |
| SE7903616L (en) | 1979-10-29 |
| JPS5516890A (en) | 1980-02-05 |
| GB2021678A (en) | 1979-12-05 |
| DE2916849A1 (en) | 1979-10-31 |
| FR2424222A1 (en) | 1979-11-23 |
| AU4647279A (en) | 1979-11-01 |
| ZA791927B (en) | 1980-06-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |