Self inking hand stamp

{
  "publication_number": "US4970954A",
  "country": "US",
  "kind": "A",
  "title": "Self inking hand stamp",
  "abstract": "A hand operated stamp with two slidable housings, one inside the other, adapted to compress springs when slid together and also to rotate a stamp die from an ink pad contacting position inside the inner housing to an imprint positioin at the bottom of the inner housing. The compression springs are attached to and removable with a cap on the outer housing to save space and allow easy replacement of the ink pad.",
  "claims": [
    "1. A self-inking hand stamp comprising: a first, oblong, generally rectangular housing having a removable cap at one end; a second, oblong, generally rectangular housing slidably disposed within said first housing, said second housing containing a replaceable, generally rectangular ink pad at the end nearest said one end thereof; rotary die pad means in said second housing adapted to move from a rest position against said ink pad to an imprint position in response to the sliding of said first housing relative to said second housing; and a plurality of springs between said ink pad and said removable cap so as to urge apart said first and second housings and so as to normally hold said rotary die pad in said rest position, each of said springs being substantially smaller than the inside dimensions of said first housing and each of said springs located in position at one end by being attached to said cap and located at the other end by retaining means on said ink pad, the attachment of said springs to the cap allowing the removal of the springs with the cap.",
    "2. The stamp of claim 1 in which said replaceable ink pad rests in a friction fit with the second housing upon ledges in said second housing so as to transfer the force of said springs into said second housing.",
    "3. The stamp of claim 1 including mount assemblies between said removable cap and said first housing, said assemblies being flexible enough to permit the cap to be snapped on and off the first housing and said assemblies being resistant to being released by the spring forces from said springs.",
    "4. The stamp of claim 3 in which said ink pad rests in a friction fit with the second housing upon ledges in said second housing so as to transfer the force of said springs into said second housing.",
    "5. The stamp of claim 4 in which said plurality of springs comprises two springs."
  ],
  "description_excerpt": "This invention relates to hand stamping devices for making ink impressions on documents, boxes or other surfaces where the printing die automatically moves from a position against an ink pad to a printing position when the stamp is pressed downward on to the surface to be imprinted. More specifically, a stamper is disclosed that can be more compact and which affords easy mess-free removal of the ink pad when replacement becomes necessary.\n\nSelf-inking stamps are known in the prior art that operate by pressing an outer housing downward so it slides down and around an inner housing. The inner housing contains a rotatable printing die that moves from a rest position against an ink pad to an imprint position in response to the relative movement of the inner and outer housings. The inner and outer housing are spring biased apart so as to hold the die normally against the ink pad when the stamp is not being compressed. Such a device is typified by the disclosure in U.S. Pat. No. 4,432,281 and the references cited therein. In this prior art patent, the outer housing includes a metal bridge that spans the housing and against which are mounted the springs that engage and bias the inner housing towards a rest position. Since the ink pad occupies essentially all of the width the inner housing, the bias springs necessarily rest against the ink pad itself. As a result, when the pad must be reinked, a rather cumbersome procedure is necessitated in which a cap on the outer housing is removed to expose the metal bridge.",
  "cpc": [
    "B41K 1/42"
  ],
  "ipc": [
    "B41K 1/42"
  ],
  "inventors": [
    "David A. Weir",
    "Richard E. Hewitt"
  ],
  "filing_date": "1990-01-09",
  "publication_date": "1990-11-20",
  "grant_date": "1990-11-20",
  "priority_date": "1990-01-09",
  "application_number": "US-46272490-A",
  "family_id": "23837535",
  "cited_by_count": 57,
  "citations": [
    "US3364856A",
    "US4432281A"
  ]
}