US3803942A - Pawls - Google Patents

Pawls Download PDF

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Publication number
US3803942A
US3803942A US00279657A US27965772A US3803942A US 3803942 A US3803942 A US 3803942A US 00279657 A US00279657 A US 00279657A US 27965772 A US27965772 A US 27965772A US 3803942 A US3803942 A US 3803942A
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US
United States
Prior art keywords
pawl
parts
chain
condition
axes
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 - Lifetime
Application number
US00279657A
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English (en)
Inventor
J Duggan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Oilwell Varco UK Ltd
Original Assignee
Drexel Equipment UK Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Drexel Equipment UK Ltd filed Critical Drexel Equipment UK Ltd
Application granted granted Critical
Publication of US3803942A publication Critical patent/US3803942A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F16G15/00—Chain couplings, Shackles; Chain joints; Chain links; Chain bushes
    • F16G15/04—Quickly-detachable chain couplings; Shackles chain links with rapid junction means are classified according to the corresponding kind of chain
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • B63B21/18—Stoppers for anchor chains
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/20—Control lever and linkage systems
    • Y10T74/20576—Elements
    • Y10T74/20582—Levers
    • Y10T74/20588—Levers toggle
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/21—Elements
    • Y10T74/2133—Pawls and ratchets
    • Y10T74/2136—Pivoted pawls

Definitions

  • ABSTRACT a A collapsible pawl applied to emergency release of a [30] Foreign Application Priority Data mooring chain or cable of a ship or rig acts either di' Au 10 1971 Great Britain 3759 1/7 1 rectly on a chain guided over a bowstopper or wildcat, or indirectly, via a toothed ring, on a chain or cable extending around a wildcat, winch, or Windlass.
  • the [52] Cl 74/577 2 i a? pawl has two parts arranged one after the other there- [511 Int Cl Fl6d 41/12 along and articulated to each other by a toggle and [58] Fieid 577 R 520 also by two lateral links.
  • the toggle is operated by a I hydraulic ram connected to a central pin of the toggle. 226/147 254/150 1 Ill/I99 200
  • the [56] References Cited toggle is operated to cause the two pawl parts to turn UNITED S S PATENTS about transverse axes.
  • a collapsible pawl comprising first'and second parts which extend one after the other along the longitudinal axis of the pawl and which are articulated to each other so as to be able to turn about axes transverse to said longitudinal axis, and means displaceable between a first condition in which said means prevents said parts from turning about said axes under the action of a compressive force along said longitudinal axis and thus prevents collapse of said pawl by said force and a second condition in which said means does not prevent said parts from turning about said axesunder the action of said force.
  • the invention has the advantage that, by equipping a chainstopper, wildcat, winch or windlass on board a ship or marine rig with the present pawl, it is'possible to provide simply and cheaply for immediate release of a chain or cable in any emergency situation.
  • FIG. 4 shows a perspective view of another part of the pawl
  • FIG. 5 shows a plan view of a first toggle link of the pawl
  • FIG. 6 shows a side elevation of the first toggle link
  • FIG. 7 shows a plan view of a second toggle link of the pawl
  • FIG. 8 shows a side elevation of the second toggle link
  • FIG. 9 shows a diagrammatic sectional side elevation of a wildcat equipped with the collapsible pawl
  • FIG. 10 shows a diagrammatic sectional side elevation of a modified version of the wildcat of FIG. 9, and
  • FIG. 11 shows a diagrammatic sectional side elevation of a windlass equipped with the collapsible pawl.
  • the bowstopper serves to carry the tension in an anchor chain 1 of which the left-hand end in FIG. I is connected to a which and the right-hand end to the anchor.
  • the bowstopper includes two side plates (of which one is seen and referenced 2) between which is pivotally mounted a lever 3 to which is fixed a guide channel 4 for the chain 1.
  • One arm of the lever 3 has at its outer end a load cell 5 which is used to indicate the tension in the portion of the chain 1 between the bowstopper and the anchor, while the other arm of the lever 3 has pivotally mounted thereon at its outer end the pawl 6 which stops movement of the chain 1 through the bowstopper towards the anchor.
  • An arm 7 fixed to the pawl 6 is used to swing the pawl upwardly into an inoperative position when it is desired to pay out the chain 1.
  • the tension in the portion of the chain 1 between the bowstopper and the anchor may increase above the pulling capacity of the winch, so that the winch is unable to draw in the chain sufficiently for the pawl 6 to be released by means of the arm 7.
  • the pawl 6 is made collapsible. For this reason, it consists of two parts 8 and 9 which extend one after theother along the longitudinal axis ll of the pawl.
  • the parts 8 and 9 are articulated to each other by means of lateral lines 12 which are connected to the parts 8 and 9 by means of horizontal pins 13 which have their axes l4 transverse to the axis 11.
  • the parts 8 and 9 are formed in the underneath of their inner ends with recesses I5 and 16 which receive toggle links 17 and 18 which are pivotally mounted at their outer ends on pins 19 and 20 provided in slots 21 and 22 in the parts 8 and 9, and are pivotally connected at their inner ends to a common pin 23.
  • the slots 2I and 22 have their axes of elongation extending parallel to the protruding top surface and 16a of the recesses 15 and 16.
  • the pin 23 is received in an eye 24 of a piston rod 25 connected to a piston 26 reciprocable in a hydraulic cylinder 27.
  • the piston rod 25 extends in a bore 28 provided fractionally in the part 8 and fractionally in the part 9.
  • the top of the part 8 has a projecting lip 29 which enters a recess 30 in the top of the part 9.
  • the cylinder 27 rests freely on a surface portion of the part 8 in this region.
  • the items 17 to 24 form a toggle which is movable through a dead-centre position in which the axes of the horizontal pins 19, 20 and 23 are co-planar. In the position shown in FIG. 2, the axis of the pin 23 is just below the common plane, but is prevented from moving downwards because the piston 26 is at the lower end of its stroke in the cylinder 27.
  • the toggle prevents the pawl parts 8 and 9 from hinging about a horizontal axis 31, which is the apex of meeting of the recesses and 16 and extends above the axis 11, under the action of compressive force applied along the axis 11. Thereby, collapsing of the pawl under the action of such force is prevented.
  • the cylinder 27 is fed with hydraulic fluid to lift the piston 26 and thus to lift the axis of the pin 23 to above the plane containing the axes of the pins 19 and 20.
  • the pawl does not yet collapse however, because the abutting inner end faces of the parts 8 and 9 are in compression against each other and because the slots 21 and 22 allow a limited amount of movement of the pins 19 and therealong until the pins 19 and 20 reach the inner ends of the slots.
  • continued lifting of the pin 23 by the piston 26 begins to turn the parts 8 and 9 anticlockwise, and clockwise, respectively, in FIG. 2 until the compressive force along the axis 11 acts to jack-knife the pawl 6.
  • J ack-knifing of the pawl 6 suddenly lifts the piston rod and thus lifts the cylinder 27 off the part 8.
  • the collapsed pawl swings clockwise until it is captured by a spring-loaded plunger (not shown) which prevents the pawl from rebounding back onto the chain 1.
  • the collapsible pawl 6 is also applicable to a wildcat, as shown in FIG. 9, wherein the anchor chain 1 extending over the wildcat 40 is prevented from moving to the right by the pawl 6.
  • a hydraulic piston-and-cylinder device 41 serves the same purpose as the arm 7 in FIG. 1.
  • the pawl 6 acts indirectly thereon via the teeth of a ratchet wheel 42 fixed co-axially to the wildcat 40.
  • FIG. 11 shows the pawl 6 applied to a windlass 43 over which extends the chain 1.
  • the windlass 43 includes a driving pinion 44 which meshes with a ring of teeth 45 on the windlass wildcat.
  • the pawl 6 has teeth 46 at its free end for engaging with the teeth 45 to prevent rotation of the windlass wildcat.
  • a collapsible pawl comprising first and second parts which extend one after the other along a longitudinal axis of the pawl and which are articulated to each other so as to be able to turn about axes transverse to said longitudinal axis, and means displaceable between a first condition in which said means prevents said parts from turning about said axes under the action ofa compressive force along said longitudinal axis and thus prevent's collapse of said pawl by said force and a second condition in which said means does not prevent said parts from turning about said axes under the action of said force, said means comprising a toggle device having first, second and third axes of pivoting, of which the second axis is disposed between the first and third axes and, when said means is in said first condition, is disposed at one side of a plane containing the first and third axes and, when said means is in said second condition, is disposed on the other side of said plane.
  • a pawl according to claim I wherein said means further comprises a fluid-operated piston-and-cylinder device connected to said toggle device for displacing the second axis of pivoting between said one side and said other side of said plane.
  • a pawl according to claim 1 wherein said means further comprises a piston rod extending from the piston of said piston and cylinder device to said second axis and connecting said piston to said toggle device, and wherein the cylinder of said piston-and-cylinder device bears freely on a surface portion of said first part when said means is in said first condition and is spaced from said surface portion when said means is in said second condition, said piston rod extending through a hole formed through said surface portion.
  • a pawl according to claim 1 wherein said first and third axes of pivoting are provided by respective pins of first and second pin-and-slot couplings connecting said first and second parts, respectively to said toggle device, said couplings providing a limited amount of play between said toggle device and said first and second parts, whereby displacement of said second axis through said plane from said one side to said other side is accompanied by the taking-up of said play until said second axis has reached a predetermined distance from said plane.
  • a pawl according to claim 1 and further compris- -ing respective recesses formed in the inner ends of said first and second parts and receiving said toggle device.
  • a pawl according to claim 1 wherein said means in said second condition applies to said first and second parts forces tending to turn said first and second parts about said axes in senses to collapse said pawl.
  • a pawl according to claim 1 and further comprising lateral link means interconnecting said first and sec ond parts.
  • a chain a wildcat guiding longitudinal movement of said chain and a collapsible pawl for engaging said chain to prevent longitudinal movement of said chain in one direction
  • said pawl comprising first and second parts which extend one after the other along the longitudinal axis of the pawl and which are articulated to each other so as to be able to turn about axes transverse to said longitudinal axis, and means displaceable between a first condition in which said means prevents said parts from turning about said axes under the action of a compressive force along said longitudinal axis produced by said chain and thus prevents collapse of said pawl by said force and a second condition in which said means does not prevent said parts from turning about said axes under the action of said force.
  • a flexible elongate member wheel means around which extends said flexible elongate member, a ring of teeth connected to said wheel means and a collapsible pawl for engaging said ring of teeth to prevent rotation of said ring of teeth in one sense and thus to prevent rotation of said wheel means in one sense
  • said pawl comprising first and second parts which extend one after the other along the longitudinal axis of the pawl and which are articulated to each other so as to be able to turn about axes transverse to said longitudinal axis, and means displaceable between a first condition in which said means prevents said parts from turning about said axes under the action of a compressive force along said longitudinal axis produced by said ring of teeth and thus prevents collapse of said pawl by said force and a second condition in which said means does not prevent said parts from turning about said axes under the action of said force.
  • said wheel means comprises one of a wildcat and a wireline drum.
  • a collapsible pawl comprising two parts which extend one after the other along the longitudinal axis of the pawl, and of which one part is pivotally mounted at said pivot means at the end of said one part further from the other part so as to be turnable about an axis transverse to said longitudinal axis, and means articulating said parts to each other so that said other part is turnable relative to said one part about an axis transverse to said longitudinal axis, said other part at its end further from said one part engaging said chain to prevent longitudinal movement of said chain in one direction,
  • a fluid-operated piston-andcylinder device disposed in the region of the two adjacent ends of said parts and acting at said region to displace said parts from a first condition in which said parts are prevented from turning relative to each other to a second condition in which said parts turn relative to each other and thus said pawl collapses.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Load-Engaging Elements For Cranes (AREA)
  • Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
US00279657A 1971-08-10 1972-08-09 Pawls Expired - Lifetime US3803942A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3759171A GB1367358A (en) 1971-08-10 1971-08-10 Pawls

Publications (1)

Publication Number Publication Date
US3803942A true US3803942A (en) 1974-04-16

Family

ID=10397596

Family Applications (1)

Application Number Title Priority Date Filing Date
US00279657A Expired - Lifetime US3803942A (en) 1971-08-10 1972-08-09 Pawls

Country Status (7)

Country Link
US (1) US3803942A (zh)
JP (1) JPS4827486A (zh)
DE (1) DE2239183A1 (zh)
FR (1) FR2148606B1 (zh)
GB (1) GB1367358A (zh)
NL (1) NL7210899A (zh)
NO (1) NO134978C (zh)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3911764A (en) * 1974-10-23 1975-10-14 James Daniel Duggan Chain guiding apparatus
US4186464A (en) * 1977-04-28 1980-02-05 Pusnes Mek, Verksted A/S Chain stopper
US4486007A (en) * 1982-07-16 1984-12-04 Intercontinental Engineering-Manufacturing Corporation Emergency pawl release system for winches
US4878452A (en) * 1987-02-10 1989-11-07 Amca International Corporation Quick-release mooring apparatus for floating vessels
US5934216A (en) * 1997-09-16 1999-08-10 Oceaneering International Inc. Method and apparatus for tensioning and deploying mooring chain
US7284496B1 (en) 2004-12-31 2007-10-23 Douceur John R Fail-safe remotely controlled chain stopper with position indicator
WO2008020761A1 (en) * 2006-08-17 2008-02-21 Rolls-Royce Marine As Device for a shark jaw
CN103507920A (zh) * 2012-06-29 2014-01-15 大连船舶重工集团有限公司 船上基于加强结构的止链器
CN103640672A (zh) * 2013-11-25 2014-03-19 无锡起岸重工机械有限公司 船用掣链器
US20150014614A1 (en) * 2012-03-07 2015-01-15 Scana Offshore Vestby As Apparatus for anchoring an offshore vessel
CN114013568A (zh) * 2021-11-12 2022-02-08 中船华南船舶机械有限公司 一种止链器的应急释放装置

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3924243A (en) * 1974-08-06 1975-12-02 Ibm Cross-field-partitioning in array logic modules
JPS5543706U (zh) * 1978-09-13 1980-03-21
GB2131380A (en) * 1982-12-08 1984-06-20 Duggan Marine Equip Ltd Collapsible chain stopper
JPS61132490A (ja) * 1984-11-29 1986-06-19 Nippon Kokan Kk <Nkk> 制鎖器
FR2630992B1 (fr) * 1988-05-03 1993-04-09 Maingret Michel Davier a barbotin mixte a cliquet
CN102941910A (zh) * 2012-11-07 2013-02-27 武汉船用机械有限责任公司 一种锚链止链器
CN114013569A (zh) * 2021-11-12 2022-02-08 中船华南船舶机械有限公司 一种具备应急释放功能的止链器
CN115107929A (zh) * 2022-07-20 2022-09-27 中交一航局第五工程有限公司 一种锚机盘缆装置及方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1226731A (en) * 1917-03-31 1917-05-22 William J Wheeler Trip riding-pawl.
US3144776A (en) * 1957-12-20 1964-08-18 Allegany Instr Company Inc Latch mechanism

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1226731A (en) * 1917-03-31 1917-05-22 William J Wheeler Trip riding-pawl.
US3144776A (en) * 1957-12-20 1964-08-18 Allegany Instr Company Inc Latch mechanism

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3911764A (en) * 1974-10-23 1975-10-14 James Daniel Duggan Chain guiding apparatus
US4186464A (en) * 1977-04-28 1980-02-05 Pusnes Mek, Verksted A/S Chain stopper
US4486007A (en) * 1982-07-16 1984-12-04 Intercontinental Engineering-Manufacturing Corporation Emergency pawl release system for winches
US4878452A (en) * 1987-02-10 1989-11-07 Amca International Corporation Quick-release mooring apparatus for floating vessels
US5934216A (en) * 1997-09-16 1999-08-10 Oceaneering International Inc. Method and apparatus for tensioning and deploying mooring chain
US7284496B1 (en) 2004-12-31 2007-10-23 Douceur John R Fail-safe remotely controlled chain stopper with position indicator
US20110041751A1 (en) * 2006-08-17 2011-02-24 Overaa Arild Device for a shark jaw
GB2453898A (en) * 2006-08-17 2009-04-22 Rolls Royce Marine Device for a shark jaw
WO2008020761A1 (en) * 2006-08-17 2008-02-21 Rolls-Royce Marine As Device for a shark jaw
GB2453898B (en) * 2006-08-17 2011-04-27 Rolls Royce Marine Device for a shark jaw
CN101506030B (zh) * 2006-08-17 2013-06-12 劳斯莱斯船业公司 鲨鱼钳
US20150014614A1 (en) * 2012-03-07 2015-01-15 Scana Offshore Vestby As Apparatus for anchoring an offshore vessel
CN103507920A (zh) * 2012-06-29 2014-01-15 大连船舶重工集团有限公司 船上基于加强结构的止链器
CN103507920B (zh) * 2012-06-29 2016-03-30 大连船舶重工集团有限公司 船上基于加强结构的止链器
CN103640672A (zh) * 2013-11-25 2014-03-19 无锡起岸重工机械有限公司 船用掣链器
CN114013568A (zh) * 2021-11-12 2022-02-08 中船华南船舶机械有限公司 一种止链器的应急释放装置

Also Published As

Publication number Publication date
FR2148606B1 (zh) 1973-08-10
NL7210899A (zh) 1973-02-13
JPS4827486A (zh) 1973-04-11
NO134978B (zh) 1976-10-11
NO134978C (zh) 1977-01-19
FR2148606A1 (zh) 1973-03-23
GB1367358A (en) 1974-09-18
DE2239183A1 (de) 1973-02-22

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