Technical Field

This invention relates, to devices for imprinting sta messages and, more particularly, this invention relates to stamping device which adjustably prints a fixed message from pre-inked stamp material.

Background Art

The fixed message stamp with custom or standard imprint is a necessary device in modern businesses, especially i bookkeeping, accounting, billing and mail handling. Th earliest stamps were hard rubber, and they were inked from pad before the message was transferred and imprinted on th document or package. However, the stamp was usually over inked and the excess ink would end up on the fingers, hand and clothing of the user. Also unnecessary and unwante imprints were made on every surface that came in contact witl the face of the stamp.

Recently, a pre-inked stamp element became available i which the ink was contained in micropores within a syntheti resin material as disclosed in U.S. Patent Nos. 2,777,824, an 3,055,297, the disclosures of which are expressly incorporate herein by reference.

U.S. Patent No. 3,625,143 is representative of patent disclosing a stamp device in which the message can be varie by rotation of a marking band of the inicroporou , syntheti resin material. However, the force of impression is variable depending on the force applied by each user and the quantity

of ink present in the band. Consequently, the band expels varying amounts of ink often resulting in blurred or smeared marks. Also, the lifetime of the stamp element is shortened due to excessive wear caused by degeneration of the microporous material due to overly forceful compression of the element. Impressions made with too light a force will not form a dark, distinct image.

These problems are avoided by stamp device having means to adjust the impressive force. Such a hand stamp device is disclosed in U.S. Patent No. 4,022,127. This device has a handle including a rota able collar which engages an adjustable stop comprising a two-part bushing of variable length to vary the relative position of the inked, message element and the message receiving surface. This device provides clear, non-blurred impressions and assures that this pre-inked element has a long, service life. However, the adjustment collar is positioned just below the handle and can be inadvertently rotated during handling or use by pressure from the thumb of the user. Furthermore, this adjustable device is mechanically complex and contains numerous parts requiring separate manufacture. This device is expensive to manufacture and assemble and is subject to mechanical failure.

Statement of the Invention

An improved, adjustable stamp device is provided in accordance with the invention which is simple in construction, economical to produce and is relatively immune to mechanical problems. The stamp device has a minimal number of parts and is constructed in a manner to provide maximum mechanical integrity by reducing the likelihood of breakage or failure. The manual stamp device permits selectable, variation of the impressive force applied to the ink-bearing element in a reliable manner. The device requires little, if any,

maintenance and provides distinct, non-blurred impressions a long life to the stamp element. These advantages a preferably attained by providing a manual stamp device havi a base for receiving an ink-bearing element, a shro surrounding said base and slidably mounted on said handle vary the impressive force applied to an ink-bearing membe resilient means urging said shroud to a first extend position, and cam means adjustably positionable to limit th length of movement of said shroud relative to said base whe in a second retracted position.

The manual hand stamp of the invention has an extremel attractive appearance, preferably being formed of a curve handle joined by a short intermediate post to a base with shroud having curved edges. The adjustment means preferabl takes the form of a recessed, concave knob or button rotatabl received in an aperture in the front or back face of th handle and is secured to the cam by adhesive or sonic, solven or thermal welding. The knob has a slot for receiving a coi or other knife-edged implement which acts as a key fo rotating the knob- cam assembly. The recessed knob also form a convenient and comfortable location for resting or placing thumb during a stamp impression.

The stamp of the invention is constructed of few part and can be mass produced at low cost from mainly plasti materials. The stamp is more reliable and convenient to use. The stamp will be more efficient in an office atmosphere sinc it will not require repackaging, or redoing of documents tha have been imprinted incorrectly or smudged. These and many other advantages and features of the present invention will be apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings.

Brief Description of the Drawings

FIGURE 1 is a front elevation view of a manual stamp device according to the present invention;

FIGURE 2 is a horizontal section through the device of FIGURE 1, taken on the line 2-2 thereof;

FIGURE 3 is a transverse section through the manual stamp device of FIGURE 1, taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a vertical section through the manual stamp device of FIGURE 1, taken on the line 4-4 of FIGURE 3; FIGURE 5 is an enlarged detail view, partly in section and with a portion of the handle shown removed, of the upper portion of the manual stamp device of FIGURE 1;

FIGURE 6 is a view similar to that of FIGURE 5 showing the cam member in an adjusted position; FIGURE 7 is a view similar to that of FIGURE 5 showing the reverse side of the cam member of the manual stamp device of FIGURE 1;

FIGURE 8 is a view similar to that of FIGURE 7 showing the cam member in an adjusted position; FIGURE 9 is a view similar to that of FIGURE 3 showing the shroud of the manual stamp device of FIGURE 1 in its most retracted position; and

FIGURE 10 is a view similar to that of FIGURE 9 showing the shroud in its least retracted position.

Detailed Description of the Invention

Figure 1 shows a manual stamping device, indicated generally at 2, having a handle member 4 which is generally in the shape of an inverted cup with flat front and rear sides, as seen at 6 and 8, respectively, in Figure 2. The front side 6 has an aperture 10 formed therein which rotatably receives an adjusting knob 12 having a concave face containing a recessed slot 16 which extends diametrically across the face

of the adjusting knob 12. The slot 16 is sized to receive coin, not shown. The knob 12 has a rearwardly facing hub which is received in a corresponding recess in the front fa of a cam wheel 14. The knob is secured to the cam 14 to fo a unitary knob-cam assembly by adhesive or welding. When t coin is rotated in the slot 10, the coin will bear against t sides of the slot 16 and will rotate the knob-cam assembly rotate the cam wheel 14 to,-a desired position.

As seen in Figures 3 and 4, the rear surface of the c wheel 14 is formed with an eccentric camming surface 20 whi engages a shoulder 22 formed on a collar 24. The collar 24 slidably mounted on a central shaft 26 and has a low shoulder 28 which is fixedly secured to the upper shoulder of a shroud member 32. The handle member 4 is formed with internal boss 34 adjacent the closed upper end 36 thereof a the boss 34 is provided with a shoulder 38 which also engag the camming surface 20 of the cam wheel 14. The boss 34 formed with an axial recess 40 which fixedly receives t upper end 42 of the shaft 26. A spring 44 is mounted on t shaft 26 between the lower end of the boss 34 and the inn surface 46 of the collar 24. The lower end 48 of the shaft 2 is fixedly secured within a central boss 50 which extend upwardly from the top surface 52 of a platen member 54. Th platen member 54 is slidably received within the shroud membe 32 and is formed with downwardly extending walls 56 fo receiving and frictiσnally retaining a micrσporous stam element, as shown at 58 in Figures 9 and 10. Finally, a dus cover 60 is frictionally retained by the shroud member 32 t protect the stamp member 58 and platen 54 from dirt or damage. As best seen in Figures 3, 5 and 6, the front surface o the cam wheel 14 is formed with a plurality o circumferentially disposed recesses 62 which are engagable b

a detent 64 formed on the inside of the front surface 6 of th handle member 4. The detent 64 serves to engage the recesse

62 of the cam wheel 14 to retain the cam wheel in a desire position of adjustment. In use, a coin is inserted into slot 16 of the adjustin wheel 12 to rotate the adjusting wheel 12 to a desire position. Since the adjusting wheel is fixedly secured to the cam wheel 14, rotation of the adjusting wheel 12 also rotates the cam wheel 14. As best seen in Figures 7 and 8, rotation of the cam wheel 14 serves to alter the position of camming surface 20 of the cam wheel 14 which bears against shoulder 38 of the boss 34 of handle member 4 and against shoulder 22 of the collar 24. This serves to selectively adjust the position of the shroud member 32 between a retracted position, as seen in Figure 9 and an extended position, as seen in Figure 10. The detent 64 of handle member 4 engages the recesses 62 of cam wheel 14 to retain the cam wheel 14 in the desired position

When the coin is removed, the external portion of the knob mechanism is gone and there is no possibility of accidental rotation of the cam. When the manual stamp device 2 is employed to print its indicia on a desired surface, the shroud member 32 will first engage the desired surface and the platen member 54 will be forced downwardly until the movement of the platen member 54 is limited by the adjustment level provided by the coin. Only a selected thickness of the stamp element extends past the shroud. This provides a control on the amount of compression of the stamp element 58 carried by the platen member 54 as it engages a surface to make an imprint thereon.

When the device is removed from the surface, the spring 44 will expand and return the shroud 32 to its first, extended position in front of and protecting the stamp element from accidentally imprinting on a surface. When the cam wheel 14

is in the position shown in Figures 6 and 8, the cammin surface 20 will allow the collar 24 and shroud 32 to retrac to the position shown in Figure 10. Accordingly, when a imprint is made with the device 2 so adjusted, the stam element 58 will be compressed at its lowest level and the imprint made will be the lightest. In contrast, when the cam wheel 14 is in the position shown in Figures 5 and 7, the camming surface 20 will allow the maximum movement of the platen member 54. Hence, the platen member containing the stamp element 58 will have its longest travel or throw and will engage the surface to be imprinted with the highest amount of compression. The resulting imprint made by the stamp element 58 will be relatively dark. Obviously, intermediate positions of the cam wheel 14 will result in intermediate darkness of the imprint made by the stamp element 58.

As described above, the adjustment knob 12 is formed with a slot 16 which is sized to receive the edge of a coin, not shown. The coin, then, serves as a handle to rotate the adjustment wheel 112 and, hence, the cam wheel 14 to a desired position. On the other hand, it will be obvious to those skilled in the art that the adjustment knob 12 could, if desired, be provided with suitable handle means secured to or formed integral with the knob. The stamp device is assembled by inserting the lower knurled end of the shaft into the boss on the platen. The shroud, collar and spring are placed on the shaft. The knob is adhered to the cam wheel and the cam wheel is snappedinto the aperture on the front surface of the handle. The upper end of the shaft ^' is inserted into the aperture in the boss inside the handle.

The stamp device can be formed of many different materials such as metal or high impact plastic. However, all parts except for the spring an shaft can be formed of plastic. The stamp contains few parts, is lightweight, yet sturdy and

reliable. It is convenient to use and gives longer useful life to the stamp element since extraneous imprints are avoided due to the retractable shroud. The element will also last longer since it is subjected to controlled compressive force, is protected by the cover when not in use and will not dry out as quickly and will not be chipped or cracked as readily.

It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing form the spirit and scope of the invention as defined in the following claims.