Pivoted artificial limb with spring loaded joint lock

{
  "publication_number": "US3833942A",
  "country": "US",
  "kind": "A",
  "title": "Pivoted artificial limb with spring loaded joint lock",
  "abstract": "An artificial arm or leg comprising a pair of rigid tubular limb members which are pivotally connected together at adjacent ends so that the pivotal connection corresponds to an elbow-joint or a knee-joint, in which one of the limb members is provided at or near the pivotal connection with a spring-loaded movable locking member adapted to engage and hold fast a toothed segment or wheel provided on and rigid with the other limb member, the locking member having an operating cord which, on being pulled once, releases the locking member so that it engages the toothed segment or wheel, and which, on being pulled a second time, moves the locking member clear of the toothed segment or wheel so that the two limb members can pivot relatively to each other.",
  "claims": [
    "1. An artificial limb comprising first and second rigid tubular limb members, means pivotally connecting the said limb members together at adjacent ends thereof so that the pivotal connection thus formed corresponds to the pivotal joint in a real limb, a hollow, axially-movable, non-rotatable locking plunger located within said first limb member adjacent the said pivotal connection, a toothed segment provided on and rigid with said second limb adjacent the said pivotal connection, a nose portion on said locking plunger adapted to lockingly engage and disengage said toothed segment as said plunger moves axially towards and away from the said pivotal connection respectively, a spring in engagement with said plunger to urge the plunger in a direction towards said pivotal connection, an operating cord connected to the locking plunger to move the plunger in the opposite direction, an axially-immovable, rotatable pawl of cylindrical shape arranged for rotation within the hollow locking plunger, a ring of axially-projecting teeth at each end of said cylindrical pawl, bevelled surfaces on the teeth of each ring of teeth, a pair of inwardly-projecting pins on the hollow locking plunger arranged to strike such bevelled surfaces on the respective rings of teeth on the cylindrical pawl when the hollow locking plunger moves first in one direction and then in the opposite direction, the pawl thereby being rotated through a small arc, and grooves of different depth between successive teeth in one of said rings of teeth on the pawl, the said grooves being adapted to receive a respective one of said pins whereby the pawl holds the nose portion of the locking plunger out of locking engagement with said toothed segment when the said one pin on the plunger lies in a groove of one depth and allows the said nose portion to lockingly engage the toothed segment when the said one pin lies in a groove of a different depth.",
    "2. An artificial limb according to claim 1, in which the hollow locking plunger is arranged for axial sliding movement in a stationary cylindrical housing located in said first limb member, there being a key-and-slot connection between the locking plunger and the cylindrical housing to prevent rotation of the locking plunger while permitting axial movement thereof.",
    "3. An artificial limb according to claim 1, in which the toothed segment has a stem located in one end of the limb member on which the segment is provided, the segment forming part of the pivotal connection between the two limb members.",
    "4. An artificial limb according to claim 1, in which an artificial hand is removably carried on the end of one of the limb members remote from the pivotal connection, the hand being operable by pulling on a cord attached to a movable part of the hand.",
    "5. An artificial limb according to claim 4, in which a post projects outwards from one of the limb members near the pivotal connection in order to carry the cord attached to the movable part of the hand.",
    "6. An artificial limb according to claim 1, in which the limb members and the pivotal connection between them are covered by a removable sleeve of foamed synthetic plastics material having an external shape resembling a human arm.",
    "7. An artificial limb according to Claim 6, in which the pivotal connection between the two limb members is flanked by a pair of freely-rotatable wheels to facilitate relative pivotal movement between the two limb members after the foamed synthetic plastics sleeve has been fitted over them.",
    "8. An artificial limb according to claim 6, in which the foamed synthetic plastics sleeve is itself covered by a flesh-coloured stocking."
  ],
  "cpc": [
    "A61F 2/64",
    "A61F 2/582",
    "A61F 2002/6854"
  ],
  "assignees": [
    "STEEPER HUGH LTD"
  ],
  "filing_date": "1973-01-19",
  "publication_date": "1974-09-10",
  "grant_date": "1974-09-10",
  "priority_date": "1973-01-19",
  "application_number": "US-32515573-A",
  "family_id": "23266664",
  "citations": [
    "GB981125A",
    "IT497032A",
    "US2979730A",
    "US3159847A",
    "US3400408A"
  ]
}