"self-lapping" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "self-",
        "3": "lapping"
      },
      "expansion": "self- + lapping",
      "name": "af"
    }
  ],
  "etymology_text": "From self- + lapping.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "self-lapping (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with self-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1944 May and June, “Notes and News: Bakerloo Tube Stock”, in Railway Magazine, page 184:",
          "text": "[...] Mr. Grierson remarks that on the L.P.T.B. tube stock in general the electro-pneumatic brake is in use, but that the new 1938 stock is fitted with the self-lapping electro-pneumatic brake, which is under the control of an automatic mercury-operated retardation controller when normal service stops are being made.",
          "type": "quote"
        },
        {
          "ref": "1961 February, R. K. Evans, “The role of research on British Railways”, in Trains Illustrated, page 95:",
          "text": "Thus, in the newer locomotives for the Great Northern line, the Woodward governors are adapted for air (not solenoid) control and continuous engine speed control through a self-lapping valve replaces the individual-speed steps, allowing operation in multiple with English Electric and Birmingham diesels.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Of a valve, especially for brakes, maintaining the force of pressure selected by a control."
      ],
      "id": "en-self-lapping-en-adj-RmvCGfLS",
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "self-lapping"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "self-",
        "3": "lapping"
      },
      "expansion": "self- + lapping",
      "name": "af"
    }
  ],
  "etymology_text": "From self- + lapping.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "self-lapping (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms prefixed with self-",
        "English terms with quotations",
        "English uncomparable adjectives",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1944 May and June, “Notes and News: Bakerloo Tube Stock”, in Railway Magazine, page 184:",
          "text": "[...] Mr. Grierson remarks that on the L.P.T.B. tube stock in general the electro-pneumatic brake is in use, but that the new 1938 stock is fitted with the self-lapping electro-pneumatic brake, which is under the control of an automatic mercury-operated retardation controller when normal service stops are being made.",
          "type": "quote"
        },
        {
          "ref": "1961 February, R. K. Evans, “The role of research on British Railways”, in Trains Illustrated, page 95:",
          "text": "Thus, in the newer locomotives for the Great Northern line, the Woodward governors are adapted for air (not solenoid) control and continuous engine speed control through a self-lapping valve replaces the individual-speed steps, allowing operation in multiple with English Electric and Birmingham diesels.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Of a valve, especially for brakes, maintaining the force of pressure selected by a control."
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "self-lapping"
}