Abstract:
A pre-inked hand-held stamp includes a pair of outwardly positioned dust cover doors that are opened by movement of the internal components of the stamp during use.

Description:
TECHNICAL FIELD 
     This application concerns hand-held stamps of the type that employ a porous, inked material bearing an image. 
     BACKGROUND 
     Certain types of pre-inked hand stamp have dust cover doors at the working end of the stamp (i.e., the end which contacts the paper or other surface to be stamped). See, for example, U.S. Pat. No. 4,579,057 (Hewitt, et al.), which illustrates a stamper having a stamp element and a one-piece cover which rotates from a position in front of the element to a position 180° away, on the top of the stamper. U.S. Pat. No. 5,826,506 (Lin) illustrates a stamper in which a pair of rotating lids is provided and actuated by pins integral to the stamp body that slide within troughs formed in each lid. 
     Still others use removable or pivotally mounted covers that are actuated by hand as necessary. Removable covers, of course, are easily lost entirely, or are inconvenient to restore to closed position, especially if the stamper is being used frequently in a single sitting. 
     A commercially available product known by the trade name Clik! is depicted in U.S. Design Pat. 544,523 but is not known to be described in a utility patent. The product has a lever mounted to a first portion of the cover, which pivots away from another portion of the cover when finger pressure acts on the lever. The stamp pad is pivotally mounted within the interior of the stamper such that the first cover portion causes the pad to pivot into position for stamping. There is no spring in this stamper and thus the unit may be left in the open position, exposing the stamp pad to dust and inadvertent discharge of ink from the pad. 
     SUMMARY 
     A pre-inked hand-held stamp includes a cover in the form of a pair of exteriorly mounted, oppositely moving dust cover doors that are automatically opened and closed by the action of the stamping operation. This allows for one-step, one-handed operation while retaining the usefulness of a dust cover that is attached to the stamp and cannot be misplaced. 
     In a preferred embodiment, the pre-inked hand-held stamp comprises a stamp body and a sub-assembly comprising a stamp die and two ends. The sub-assembly is reversibly movable between a first position fully within the interior of the stamp body, and a second position in which the exposed, inked face of the stamp die slightly extends beyond the stamp body to be presented to or otherwise address the workpiece. The stamp also comprises a pair of dust cover doors, each pivotably mounted to the exterior of the stamp body by inwardly directed pins integral to the dust cover doors. Movement of the subassembly toward the workpiece outside the stamp body engages the pins to pivot the dust cover doors open, enabling the subassembly to emerge from within the stamp body and deliver ink to the workpiece. 
     It is possible for the sub-assembly to withdraw back into the interior of the stamp body and allow gravity or another mechanism (e.g., auxiliary springs) to return the dust cover doors back to their original position. However, in the preferred embodiment, the inwardly directed pins are also engaged by the reversed movement of the subassembly to draw the dust cover doors closed as the subassembly retreats into the interior of the stamp body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying figures show a particular preferred embodiment as an example, but such illustration is not intended to limit the scope of the claims. In particular, the proportions and/or dimensions that may be shown in, or suggested by, the figures are preferred but not required except as specifically set forth in the claims. 
         FIG. 1  is a front assembled view of a preferred embodiment. 
         FIG. 2  is a perspective view of the same embodiment in use. 
         FIG. 3  is an exploded perspective view of the same embodiment. 
         FIG. 4  is an assembled end view of the same embodiment. 
         FIG. 5  is a top view of a component of the same embodiment. 
         FIG. 6  is a bottom view of the same embodiment with the dust cover doors closed. 
         FIG. 7  is a cross-sectional front view taken along the lines  7 - 7  of  FIG. 4 . 
         FIG. 8  is a cross-sectional end view taken along the lines  8 - 8  of  FIG. 1 . 
         FIG. 9  is a perspective view of the dust cover door component of the illustrated embodiment. 
         FIG. 10  is a cross-sectional end view taken along the lines  10 - 10  of  FIG. 9 . 
         FIG. 11  is an end view of the chimney component of the illustrated embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In general terms, several types of pre-inked hand-held stamps (or stampers) are known commercially. Therefore, conventional details of construction and operation of components not specific to the claims are not recited below, but are within the skill in the art. In particular, various components may fit together as depicted in the figures even if such fitting is not specifically described below. 
     Referring to the Figures, the preferred embodiment of a pre-inked hand stamp indicated as  100  comprises a handle  1  which snaps onto a sub-assembly known in the art as chimney  4 , while ferrule  2  attaches onto the shaft  41  of chimney  4 , the latter passing though an opening  31  in the interior of stamp body  3  (see  FIG. 5 ). The extent of downward travel of handle  1 , and thus of chimney  4 , relative to stamp body  3  may be limited by the extent to which ferrule  2  may travel before internally contacting stamp body  3 , or by the handle contacting the body, as known in the art. A spring  11  between ferrule  2  and stamp body  3  is compressed by the downward travel of ferrule  2 , thus providing sufficient spring force to return handle  1  to its initial position when released. As explained in greater detail below, downward movement of chimney  4  also moves dust cover doors  8  outwardly to expose stamp die  6  at the bottom of chimney  4  so that it may strike the workpiece (paper or other surface) outside the interior of the stamp body. In this embodiment, upward movement of handle  1  moves dust cover doors  8  inwardly to close the bottom of stamp  100  and thus protect stamp die  6  from dust when it is not exposed. During this reversible movement of chimney  4  within stamp body  3  that causes dust cover doors  8  to swing open, support feet  9  (typical of two illustrated) formed in body  3  are stationary against the workpiece. Stamp die  6  (which may be a collection of materials as well known in the art) is held in place by retainer  7 , which clips onto chimney  4  and has an open area that exposes the bottom face of stamp die  6  to the workpiece. Stamp die  6  may be supplied in a pre-inked condition, preferably pre-installed within chimney  4 , or may have ink added to it according to known techniques by removing handle  1  and dispensing ink into either of the open columns  42  of chimney  4 . 
     Turning to  FIGS. 9-11 , each dust cover door  8  comprises first and second ends  81  that lie on opposite ends of dust cover door  8  and are connected to each other by a generally planar side  82  that is mutually perpendicular to each end  81 ; first and second ends  81  are further connected to each other by a generally planar door face  83 . The door face  83  has an edge  84  mating with its counterpart on the other door face  83  when the two dust cover doors  8  are in the closed position. Each of two slots  85  formed in the door face  83  enables the two door faces  83  to fully close together above the plane of the work surface. This is assisted by small notches  32  that are formed at corresponding locations of each end  35  of the stamp body  3  (see also  FIG. 3 ). The notches  32  allow the dust cover doors  8  to fully close together yet provide for each side section  82  to lie flush with the side  35  of stamp body  3  when the dust cover door  8  is in the closed position (see also  FIG. 4 ). 
     Each end section  81  has an inwardly-directed hinge pin  86  which fits within a corresponding circular opening  36  in the side  35  of stamp body  3  (see also  FIG. 3 ). Each hinge pin  86  has a cylindrical base  87  lying in the circular opening  36  and, extending further inwardly from cylindrical base  87 , a wedge  88 . The outer (i.e., toward the side of the stamp) directed wedge face  88   a  of wedge  88  mates with feature  46   a  defined in channel  46  of chimney  4  (see also  FIG. 4 ), so that downward motion of the latter pivots dust cover door  8  outwardly, i.e., from closed to open. In this manner, pressing the handle downward opens the dust cover doors  8  to allow the chimney  4  (and thus the stamp pad  6 ) to pass though the open lower end of the stamp body  3  and toward the work surface. 
     In this preferred embodiment, when spring  11  returns the handle  1  and chimney  4  upward, the other feature  46   b  on the chimney  4  engages the inwardly-directed wedge face  88   b  of the wedge  88  to move the dust cover doors  8  back to the closed position. They remain closed by the force provided by the spring  11 , which holds the handle  1  and chimney  4  in the upright position. In this manner, dust cover doors  8  remain closed even if the entire stamp unit  100  is inverted. However, in other embodiments, gravity or another mechanism (e.g., auxiliary springs) (not illustrated) may return the dust cover doors  8  back to their original position, at least when stamp  100  is oriented upright as illustrated in at least  FIGS. 1 and 2 . In such cases, feature  46   b  and wedge face  88   b  may be omitted or modified as required. 
     Returning to the preferred embodiment illustrated, wedge faces  88   a  and  88   b  form an angle of approximately 63° between themselves, although this value will also depend on the dimensions and shapes of features  46   a  and  46   b , which mate with wedge faces  88   a  and  88   b . The vertex of the angle between wedge faces  88   a  and  88   b  is preferably beveled as required for smooth operation. 
     The stamp  100  is preferred to have symmetrical construction as illustrated in the Figures, such that each dust cover door  8  is identical to each other (as are the two ends of chimney  4 , i.e., channel  46  and features  46   a  and  46   b ). Thus, they may be interchanged with each other. This is only a preference and not a requirement. It is possible for hinge pins  86  (and the features of the same) to mate with corresponding but non-identical channels, if it is desired to have non-identical doors or identical doors which may be mounted to stamp body  3  in only one orientation. 
     Many of the specific details of the components described in this application are dictated to large degree by the design and engineering of the preferred embodiment illustrated. However, such details are not necessarily required in the broadest embodiment enabled by this application. Similarly, alternative constructions that achieve the same functions as the components and features described in this application are within the scope of the broadest embodiment, unless specifically excluded by the following claims.