{
  "patent_number": "US 4031893",
  "country": "US",
  "title": "How Auto-Injectors Adjust Their Dose Using a Simple Spacer",
  "original_title": "Hypodermic injection device having means for varying the medicament capacity thereof",
  "summary": "A 1977 invention for auto-injectors that uses a physical spacer to adjust the amount of medicine inside the device before it is fired.",
  "what_it_does": "This patent describes an auto-injector mechanism that allows the same device to hold different amounts of liquid medication. It achieves this by placing a spacer between the spring-loaded plunger and the piston inside the medicine cartridge. By changing the thickness or presence of this spacer, the piston is pushed further into the cartridge, effectively shrinking the volume of the medicament chamber. This ensures that the device can be calibrated for specific doses without needing to redesign the entire spring-power assembly.",
  "what_it_does_not_cover": [
    "Does not cover electronic or digital dose-setting mechanisms",
    "Does not cover devices that use multiple chambers to mix medications",
    "Does not cover needle-free jet injection systems",
    "Does not cover the internal spring-power release mechanism itself"
  ],
  "filed": "1976-05-14",
  "granted": "1977-06-28",
  "expires": "1996-05-14",
  "status": "expired",
  "holder": "Survival Technology Inc",
  "holder_url": "https://patentbrief.org/company/survival-technology-inc",
  "inventors": [
    {
      "name": "Sheldon Kaplan",
      "url": "https://patentbrief.org/inventor/sheldon-kaplan"
    },
    {
      "name": "George B. Calkins",
      "url": "https://patentbrief.org/inventor/george-b-calkins"
    },
    {
      "name": "Stanley J. Sarnoff",
      "url": "https://patentbrief.org/inventor/stanley-j-sarnoff"
    },
    {
      "name": "N. Lawrence Dalling",
      "url": "https://patentbrief.org/inventor/n-lawrence-dalling"
    }
  ],
  "times_cited": 108,
  "tags": [
    "biotech",
    "mechanical",
    "consumer_electronics"
  ],
  "abstract": "A hypodermic injection device comprising a cartridge holder having a cylindrical body open at one end and closed at the other end, the closed end being provided with an aperture, a cartridge with the holder, the cartridge including an ampoule having a cylindrical sleeve open at one end and having a necked portion at the other end to receive a hub mounting a cannula, the cannula facing the apertured end of the cylindrical body, a piston slidably carried within the sleeve adjacent the open end thereof to define a medicament chamber between the piston and cannula, fluid medicament in the medicament chamber, the piston having a concave face on the side forming one end of the medicament chamber, a spring power assembly adjacent the open end of the ampoule sleeve for moving the cartridge forward and for injecting the fluid medicament, spacer means positionable between the outer face of the piston and the adjacent spring power means to vary the position of the piston within the ampoule sleeve and thereby control the volume of the medicament chamber and the medicament carried therein, a safety assembly for controlling actuation of the spring power assembly, and a resilient sheath covering the cannula to maintain the cannula in sterile condition.",
  "url": "https://patentbrief.org/patent/us/4031893/epipen-autoinjector-kaplan",
  "markdown_url": "https://patentbrief.org/patent/us/4031893/epipen-autoinjector-kaplan/md",
  "google_patents_url": "https://patents.google.com/patent/US4031893",
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}