US3875822A - Lever-operated ratchet devices - Google Patents

Lever-operated ratchet devices Download PDF

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Publication number
US3875822A
US3875822A US486201A US48620174A US3875822A US 3875822 A US3875822 A US 3875822A US 486201 A US486201 A US 486201A US 48620174 A US48620174 A US 48620174A US 3875822 A US3875822 A US 3875822A
Authority
US
United States
Prior art keywords
pawls
holding
lever
ratchet
ratchet device
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
US486201A
Other languages
English (en)
Inventor
Cyril Edward Charles Erith
Gordon Charles Elkins
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.)
MULTI STROKE HANDBRAKE CONTROL
MULTI-STROKE HANDBRAKE CONTROLS Ltd
Original Assignee
MULTI STROKE HANDBRAKE CONTROL
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 MULTI STROKE HANDBRAKE CONTROL filed Critical MULTI STROKE HANDBRAKE CONTROL
Application granted granted Critical
Publication of US3875822A publication Critical patent/US3875822A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/02—Brake-action initiating means for personal initiation
    • B60T7/08—Brake-action initiating means for personal initiation hand actuated
    • B60T7/10—Disposition of hand control
    • B60T7/102—Disposition of hand control by means of a tilting lever
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S254/00—Implements or apparatus for applying pushing or pulling force
    • Y10S254/12—Pawls
    • 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
    • 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
    • Y10T74/214—Multiple tooth

Definitions

  • a lever-operated ratchet device includes a ratchet Julv 10, 1973 United Kingdom 32/97/73 Wheel different Surfacg Pomtms which are engaged by holding and application pawls.
  • the pawls can be [52] Cl 74/575; 74/577 M; 254/1310 12 interchanged to provide fresh surface portions for en- 1511 Int. Cl. Fl6d 41/12 gagemeht With the ratchet Wheel 50 that the effective [53] Field of Search U 74/575 R, 577 142; life of the pawls is doubled.
  • the pawls are preferably 245/1316 12 identical but differently positioned depending on whether they are performing the holding or driving [56] References Cited funcnon' UNITED STATES PATENTS 2.970490 8 Claims.
  • Multi-stroke handbrake control devices normally have a ratchet wheel which provides one side plate of the cable drum and which is engaged by a springloaded holding pawl and actuated by a spring-loaded application pawl mounted on a control lever which shares a common pivot axis with the ratchet wheel. After considerable use the pawls wear and have to be replaced, and the object of the invention is to provide a very considerably increased life for the pawls.
  • a lever-operated ratchet device has holding and application pawls which have different surface portions engaging the ratchet wheel such that the pawls can be interchanged to provide fresh surface portions for engagement with the ratchet wheel.
  • the effective life of the pawls is doubled, and the pawls are preferably identical but differently positioned according to whether they are performing the holding or driving function.
  • the pawls have surface portions which interengage when the lever is moved fully in the nondrive or freewheeling direction, such interengagement moving both pawls to and holding them in a disengaged condition with respect to the ratchet wheel.
  • the formation of the pawls is desirably such that interchanging the pawls brings different interengaging surface por tions into use. so that changing over the pawls renews all operative surfaces thereof, and a projecting portion of one pawl desirably meshes with a re-entrant portion of the other.
  • the interengagement of the pawls'desirably serves to limit movement of the lever in the nondrive direction so that the provision of the usual stop for this purpose is unnecessary.
  • Torsion springs which urge the pawls into engagement with the wheel preferably have spring arms which engage different abutment points positioned so that the appropriate spring loading is provided for the pawls, to this end the profile of each pawl providing two definite spring abutment points respectively engaged when in the holding and application positions of the pawl. This obviates the drilling of spring-engaging holes in the pawls, as is the present practice.
  • the pawls may be made from forgings, castings, or steel bar or strip suitably machined. However, they may be produced by a sintering process, using accurate dies and a material specification calculated to provide high efficiency and an adequate safety margin.
  • FIG. 1 is a front view of the ratchet device
  • FIG. 2 is a plan view, partly in section, corresponding to FIG. 1,
  • FIG. 3 is a corresponding vertical sectional view through the ratchet wheel axis
  • FIG. 4 shows a pawl profile utilised in the device.
  • An operating lever 8 of rectangular section and with a generally circular flat inner end portion 9 is freely pivotable on the axle 3 between the backplate 4 and the ratchet wheel 2.
  • a button-headed socket screw 18 passes through the cover plate 5 into the end of the axle 3.
  • An application pawl 15 pivotally mounted on the lever 8 adjacent the ratchet wheel 2 is spring loaded into engagement with the latter by a torsion spring 16 which surrounds a pivot 17 on which that pawl is mounted.
  • the cranked section of the cover plate 5, as shown in FIG. 3, extends around and has a close clearance with respect to the adjacent side ll of the drum, i.e. the side opposite to the ratchet wheel, and the adjacent side edge of the ratchet wheel. In each case the clearance is less than the diameter of the cable used so that the latter cannot jump off the drum.
  • the cover plate 5 performs the dual function of preventing the cable jumping off the drum 1 and oftying together the axle 3 and the holding pawl pivot stud 6, while also providing a seating for the spring washer 10.
  • the two pawls l3 and 15 are of sintered form and identical, but employ entirely different operative machined edge surface portions so that they can be interchanged to bring a completely new set of surfaces into use.
  • the shape of one pawl will now be described in some detail with reference to FIG. 4.
  • a boss 20 projects each side of the pawl, to act as a spacer, and has a central pivot bearing bore 21.
  • a toothed portion 22 projects to one side of the boss 20, this portion having a side tooth 23 for holding engagement with the ratchet wheel and an end application tooth 24 for driving engagement therewith.
  • This end tooth 24 defines one side of a V-shaped notch of A tail portion 25 which projects to the other side of the boss 20 has mutually inclined end faces A and B with an included obtuse angle of 136, which is also the re-entrant angle between one side face C of the holding tooth 23 remote from the boss and an adjacent side face D of the toothed portion 22.
  • the pawls l3 and 15 are mounted on their pivots with the toothed portions 22 both leading in the driving sense, the formation being such that one pawl is merely turned over as compared with the other to bring the appropriate tooth 24 or 23 into operation.
  • the torsion spring 14 of the holding pawl 13 has two limbs or tangs 14a and 14b of which tang 14a engages the edge of the backplate 4 and tang 14b engages a concave abutment region 26 of the corresponding pawl close to the boss 20 and on the edge of the toothed portion 22 on the opposite side to the holding tooth 23.
  • the application pawl sprung 16 has one end limb 16a in the form of an inturned radial bar which locates in a cross slot in the corresponding pawl pivot 17.
  • the other limb or tang 16b engages a concave abutment region 27 on the driving pawl provided at the apex of the re-entrant angle of 136 on the toothed portion 22.
  • a different spring abutment region is provided for each pawl position, in each position the correct spring force being obtained. This is essential to correct operation of the device.
  • Movement of the lever 8 in the freewheeling nondrive direction is limited by interengagement of the pawls l3 and 15, such engagement serving to release both pawls from the ratchet wheel and hence relieve the cable tension as the drum 1 is now unrestrained apart from the braking torque produced by said spring washer 10.
  • the tail portion of the application pawl meshes with the tooth portion of the holding pawl, the 136 angle between the end faces A and B of the tail portion of the driving pawl mating with the similar but re-entrant angle between the face C of the holding tooth and the adjacent side face D of the holding pawl.
  • the formation of the pawl faces is such that they interengage with a mutual camming action whereby to turnthem to the release position.
  • the circular inner end 9 of the lever 8 which may be a stamping or pressing, provides a thrust bearing face for the drum 1, this face being in bearing contact with the adjacent side face of the drum.
  • the opposite side 11 of the dum has a recess 30 in which a grease nipple 31 is positioned, this nipple feeding a grease passage 32 parallel to the drum axis and offset radially by an amount slightly less than an overall radius of the circular end 9 of the lever.
  • This passage 32 breaks into the outer end of a radial slot 33 machined in the side face of the drum contacting the lever, this slot 33 extending radially inwardly to the centre bore through which the axle 3 passes.
  • An axially directed slot 34 is machined in this bore, extending throughout the full axial width of the drum from the inner end of the radial slot 33.
  • a lever-operated ratchet device having holding and application pawls which have different surfaces portions engaging the ratchet wheel such that the pawls can be interchanged to provide fresh surface portions for engagement with the ratchet wheel.
  • a ratchet device according to claim 1, wherein the holding and application pawls are identical but differently positioned.
  • a ratchet device according to claim 1, wherein the pawls have surface positions which interengage when the lever is moved fully in the non-drive or freewheeling direction, such interengagement moving both pawls to and holding them in a disengaged condition with respect to the ratchet wheel.
  • a ratchet device wherein interchanging the pawls brings different interengaging surface portions into use, so that changing over the pawls renews all operative surfaces thereof.
  • a ratchet device wherein a projecting portion of one pawl meshes with a re-entrant portion of the other.
  • a ratchet device according to claim 3, wherein limitation of lever movement in the non-drive direction is provided by the interengagement of the pawls.
  • torsion springs for urging the pawls into engagement with the ratchet wheel have spring arms whichengage different abutment points positioned so that the appropriate spring loading is provided for the pawls, the profile of each pawl providing two definite spring abutment points respectively engaged when in theholding and application positions of the pawl.
  • a ratchet device wherein the pawls are formed by a sintering process using precision dies.

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Transmission Devices (AREA)
  • Flexible Shafts (AREA)
  • Braking Arrangements (AREA)
US486201A 1973-07-10 1974-07-05 Lever-operated ratchet devices Expired - Lifetime US3875822A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3279773A GB1437625A (sv) 1973-07-10 1973-07-10

Publications (1)

Publication Number Publication Date
US3875822A true US3875822A (en) 1975-04-08

Family

ID=10344137

Family Applications (1)

Application Number Title Priority Date Filing Date
US486201A Expired - Lifetime US3875822A (en) 1973-07-10 1974-07-05 Lever-operated ratchet devices

Country Status (10)

Country Link
US (1) US3875822A (sv)
JP (1) JPS5037946A (sv)
CA (1) CA1009061A (sv)
DE (1) DE2433011A1 (sv)
FR (1) FR2237085B1 (sv)
GB (1) GB1437625A (sv)
IT (1) IT1015768B (sv)
NL (1) NL7409293A (sv)
SE (1) SE7409048L (sv)
ZA (1) ZA744299B (sv)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4876912A (en) * 1987-10-13 1989-10-31 Claas Ohg Switching mechanism for driving self-propelling agricultural machines
US5245898A (en) * 1992-07-20 1993-09-21 Berkel Incorporated Slicing machine lift arrangement
US5582370A (en) * 1994-08-19 1996-12-10 General Railway Signal Corporation Switch machine with ratchet mechanism on hand throw mechanism
US6851652B1 (en) * 2003-09-18 2005-02-08 Han-Ching Huang Telescopic support
US20140066994A1 (en) * 2012-09-06 2014-03-06 Stryker Trauma Ag Instrument for use in bending surgical devices
US20150251726A1 (en) * 2014-03-05 2015-09-10 Sun Race Sturmey-Archer Inc. Derailleur apparatus for bicycles
CN105422773A (zh) * 2015-12-23 2016-03-23 苏州市凯业金属制品有限公司 一种连杆式棘轮机构

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2136085B (en) * 1983-02-25 1986-06-18 Multi Stroke Handbrake Control Improvements in or relating to lever-operated ratchet devices
FR2618742B1 (fr) * 1987-07-30 1991-05-31 Thibault Essieux Rtn Frein de parcage pour remorque equipee d'un dispositif de freinage a inertie
GB2306628A (en) * 1995-10-23 1997-05-07 Bradley Doublelock Ltd Parking brake
DE10306383A1 (de) * 2003-02-15 2004-09-30 Adam Opel Ag Betätigungsvorrichtung für eine Feststellbremse eines Kraftfahrzeuges

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2970490A (en) * 1959-01-29 1961-02-07 Robert L Winland Hoist structure
US3003359A (en) * 1960-06-23 1961-10-10 Maasdam Felber Power unit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2970490A (en) * 1959-01-29 1961-02-07 Robert L Winland Hoist structure
US3003359A (en) * 1960-06-23 1961-10-10 Maasdam Felber Power unit

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4876912A (en) * 1987-10-13 1989-10-31 Claas Ohg Switching mechanism for driving self-propelling agricultural machines
US5245898A (en) * 1992-07-20 1993-09-21 Berkel Incorporated Slicing machine lift arrangement
US5582370A (en) * 1994-08-19 1996-12-10 General Railway Signal Corporation Switch machine with ratchet mechanism on hand throw mechanism
US6851652B1 (en) * 2003-09-18 2005-02-08 Han-Ching Huang Telescopic support
US20140066994A1 (en) * 2012-09-06 2014-03-06 Stryker Trauma Ag Instrument for use in bending surgical devices
US9839463B2 (en) * 2012-09-06 2017-12-12 Stryker European Holdings I, Llc Instrument for use in bending surgical devices
US20150251726A1 (en) * 2014-03-05 2015-09-10 Sun Race Sturmey-Archer Inc. Derailleur apparatus for bicycles
US10059401B2 (en) * 2014-03-05 2018-08-28 Sun Race Sturmey-Archer Inc. Derailleur apparatus for bicycles
CN105422773A (zh) * 2015-12-23 2016-03-23 苏州市凯业金属制品有限公司 一种连杆式棘轮机构

Also Published As

Publication number Publication date
FR2237085A1 (sv) 1975-02-07
DE2433011A1 (de) 1975-01-30
SE7409048L (sv) 1975-01-13
IT1015768B (it) 1977-05-20
NL7409293A (nl) 1975-01-14
ZA744299B (en) 1975-07-30
AU7089374A (en) 1976-01-08
GB1437625A (sv) 1976-06-03
CA1009061A (en) 1977-04-26
JPS5037946A (sv) 1975-04-09
FR2237085B1 (sv) 1979-03-16

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