Winch mechanism

{
  "publication_number": "US3770244A",
  "country": "US",
  "kind": "A",
  "title": "Winch mechanism",
  "abstract": "A winch of the type for providing windup force to running rigging, such as sheets of a vessel, constitutes an elongated cylindrical winch drum pivotally attached to a stationary spindle mounted to a base or stable surface, such as a deck or the like, of the vessel, and a hand-powered leverage bar employed to rotate the winch drum about the spindle during stroking movement of the leverage bar in a first angular direction over an arcuate sector defined by a sector angle theta measured at the spindle for the purpose of tensioning the rigging connected in gripping contact with the working surface of the drum. The improvement of the present invention utilizes only a sector of the total available circumferentially extending working surface of the drum, the sector of the drum being in contact with only a small amount of the running rigging, yet providing the required amount of buildup force for performing useful work. In one aspect of the present invention, a linking assembly is utilized for permanently connecting the leverage bar relative to the spindle. The linking assembly includes a planar toggle bar. The toggle bar has an end permanently connected to the drum so that both are of rotation of substantially parallel to that of the stationary spindle. Such attachment effectively divides the leverage bar into a handle segment to which human-engendered rotational force can be applied, and a follower segment carrying a capture surface adapted to undergo swingable rotation about the knee pin means in response to operative conditions provided by the human-engendered rotational force applied at the handle segment. During operations, the capture surface travels along a double-crescent pathway, the first crescent segment has a center formation substantially coincident with the knee pin means. Its arcuate travel length terminates in intersection with the segment of the rigging disposed on the sector of the drum utilized to provide the required windup force to the rigging. The result: frictional capture of the segment of rigging between the leverage bar and the drum without the customary need to form several loops or turns of the rigging about the entire circumferential working surface drum. The second crescent pathway segment has a center formation coincident with the stationary spindle. Its travel length is defined by the common sector angle theta. After the rigging is captured between the leverage bar and the drum, the rigging is rotated about the stationary spindle by corresponding rotation of the leverage bar over the sector angle theta to provide the required windup force for tensioning the rigging. Spring-loaded cam cleats upstream from the linking assembly can be utilized to retain the running rigging in place when the leverage bar is not in capturing contact with the rigging. Such operative condition occurs when the capture segment of the bar is traveling along the aforementioned first crescent pathway segment as well as when the leverage bar is being returned to its original starting position after the running rigging has been rotated through the sector angle theta.",
  "claims": [
    "1. In a winch of the type for providing windup force to running rigging such as sheets, halyards, and the like of a vessel, having an elongated cylindrical hub pivotally attached to a stationary pin mounted to a base or stable surface such as a deck or mast or the like of said vessel, and a hand-powered leverage bar employed to rotate said hub about said pin about a first axis rotation in incremental angular stroking steps each being in a first angular direction over an arcuate sector measured at said secondary pin for the purpose of tensioning said rigging disconnectably connected in gripping contact with a working surface of said cylindrical hub in a working plane of rotation substantially transverse to said first axis of rotation, the improvement which utilizes only a sector of total circumferential working surface of said hub in contact with only a small segment of said running rigging to provide required windup force, comprising: a. a linking assembly permanently connecting said leverage bar relative to one of said hub and stationary pin and including a planar toggle bar and a knee pin means, said toggle bar having a broad top wall surface perManently connected at one end to said hub and including a first wall means at said one end in pivotal engagement with said stationary pin, said knee pin means having a base connected to said toggle bar at an opposite end cantilevered from said stationary pin and a central elongated wall means depending from said base pivotally connected to said leverage bar along a second axis of rotation substantially parallel to said first axis of rotation, b. said leverage bar attaching to said knee pin means at a point intermediate to ends thereof to define a handle segment to which human-engendered rotational force can be applied, and at an opposite end, a follower segment carrying a capture surface thereon adapted to undergo swingoff rotation in response to operative conditions, provided by said human-engendered rotational force which defines a double-crescent pathway in said plane of rotation, said double-crescent pathway including a crescent pathway segment having a center of formation substantially coincident with said knee pin means and an arcuate travel length terminating in intersection with said segment of rigging disposed on said sector of said working surface of said hub thereby permitting frictional capture of said segment of rigging between said follower segment of said leverage bar and said sector of working surface of said hub, and a second crescent pathway segment having a center of formation coincident with said stationary pin and having a selected arcuate travel length whereby said captured segment of running rigging can be carried in rotation about said stationary pin over said sector angle theta during each incremental arcuate step of said leverage bar and thus be provided with windup force for tensioning said running rigging.",
    "2. Improvement of claim 1 in which said hub is a wedge of a cylinder of radius R, said wedge defining an outer surface forming said working sector of said hub and including near wall means having an axis of symmetry substantially coincident with an axis of formation of said outer surface, said near wall means being positioned in pivotal contact with said stationary pin.",
    "3. Improvement of claim 1 further characterized by said toggle bar means between said hub and said leverage bar being adapted to be operative in response to human-engendered return force applied to said handle segment of said leverage bar in a second angular direction opposite to said first direction so as to cause retrogressive counterrotation of said hub thereby returning said hub to its original work position, said human-engendered return force having a component of force parallel to the axis of symmetry of said leverage bar to cause said retrogressive counterrotation of said hub.",
    "4. Improvement of claim 1 in which said hub is a modified cylinder of radius R0 having a central wall means in contact with said stationary pin and an outer circumferential surface remote from said central wall means modified to include a flattened sector at a minimum radial distance R1 from said central wall means where R1 is less than R0, said flattened sector comprising said segment of working surface of said hub onto which said segment of running rigging is disconnectably connected in said plane of rotation.",
    "5. Improvement of claim 4 in which said capture surface of said leverage bar is further characterized by a wedge-like cleat means pivotally attached to said follower segment of said leverage bar, said wedge-like cleat means having an axis of rotation substantially transverse to said working plane of rotation and includes a planar surface remote from said axis of rotation adapted to operatively contact said segment of running rigging at a side diametrically opposite to said flattened sector of said hub thereby effecting rigid engagement of said running rigging relative to hub during rotation about said stationary pin.",
    "6. Improvement of claim 5 in which said outer circumference surface of said modified cylindrical hub absent said flattened secTor is provided with a groove means over a central region thereof for maintaining said running rigging in alignment with said plane of rotation as said hub and leverage bar undergo rotation in said first direction.",
    "7. Improvement of claim 5 in which said cleat means includes associated means for limiting arcuate rotation of said cleat means relative to said follower segment of said leverage bar during arcuate travel along said double-crescent pathway in said plane of rotation, whereby correct orientation can be maintained.",
    "8. Improvement of claim 1 in which said knee pin means pivotally attaching said leverage bar relative to said hub is further characterized by its being positioned longitudinally nearer to said capture surface of said leverage bar than to said handle segment whereby said capture surface of said follower segment can be maintained at capturing contact with said running rigging using a minimum component of said human-engendered rotational force.",
    "9. Improvement of claim 8 in which said capture surface of said leverage bar in contact with said segment of running rigging, generates a frictional force (Fc) having a magnitude greater than and in an opposite direction to tensioning force (Ft) acting at a remote end of said running rigging.",
    "10. Improvement of claim 9 in which said frictional force (Fc) is a direct function of said human-engendered force (F) applied to said handle of said leverage bar and of a factor (C) greater than unity in the equation C L1/L2 where L1 is the distance in said plane of rotation from said knee pin means to a central projected location of said human-engendered rotational force at said handle segment and L2 is the distance in said plane of rotation from said knee pin means to a central point of said capture surface of said leverage bar.",
    "11. Improvement of claim 10 in which said human-engendered force (F) applied to said handle segment of said leverage includes a bias force (F1) and a rotational force (F2), operative during rotation of said hub and leverage bar about said stationary pin means wherein bias force F1 is the force which establishes said frictional force (Fc) at said capture surface of said leverage bar, and rotational force F2 is the force for rotating said hub, said running rigging, said leverage bar and said linking assembly in unitary rotation about said stationary pin.",
    "12. Improvement of claim 11 in which said rotational force (F2) must be sufficient in magnitude to establish a rotational torque (T) to cause unitary rotation of said hub, said running rigging, said linking assembly and said leverage bar about said stationary pin, said rotational torque (T) being equal to F2 X D3 where F2 is as defined above and D3 is the distance from said stationary pin to a projected central point of application of said rotational force F2 in said plane of rotation.",
    "13. Improvement of claim 8 in which the leverage bar is further characterized by step means formed in said handle segment so positioned with respect to said knee pin means so as to allow said handle segment of said leverage bar to ride over said hub during counterrotation of said leverage bar in a second direction opposite to said first direction to thereby reorient said leverage bar from a right-hand position of operation to a left-hand operating position with respect to said hub and said stationary pin."
  ],
  "cpc": [
    "B63H 9/10"
  ],
  "assignees": [
    "MC CLOUD R"
  ],
  "filing_date": "1972-01-18",
  "publication_date": "1973-11-06",
  "grant_date": "1973-11-06",
  "priority_date": "1972-01-18",
  "application_number": "US-3770244D-A",
  "family_id": "22816002",
  "citations": [
    "GB735430A",
    "US1893723A"
  ]
}