US2778306A - Sealed stamp pad - Google Patents

Description

Jan. 22, 1957 C. C.YHARRIS SEALED STAMP PAD Filed Aug. 28, 1953 INVENTOR a l m UM /m c L m4 M mg C w BY WMS ATTORNEYS United States Patent SEALED STAMP PAD Carl C. Harris, Orange, Mass. Application August 2S, 1953, Serial No. 377,031 3 Claims. (Cl. 101-333) The present invention relates to marking devices and more particularly to manu-ally operated devices usually referred to as hand stamps or rubber stamps such as dating stamps, signature stamps, and the like, in common use in practically all business, and professional offices.

Hand stamping equipment is in wide use for various purposes and the present day hand stamping equipment usually consists of a stamp and an ink pad. The stamp usually has a rubber face containing the material or information to be `stamped and the usual ink pad now in use comprises a shallow canister containing a yielding absorbent material. Ordinarily, the canister is provided with a hinged lid or cover. The inks presently used in the ink pad are relatively slow drying inks `so that the ink will maintain its inking characteristics for a long period of time. Since the ink pads are left open for substantial periods of time, a quick drying ink containing a volatile solvent is undesirable due to -the Anecessity of frequent reinking. Also, most Volatile solvents have disagreeable odors and could not be used -around a` home or office unless ltightly sealed.

The stamped impression on the paper or other article is usually relatively slow drying and consequently is easily smeared and moist. Although the pad is normally covered when not in use, stamps are frequently left in a desk drawer and, since they retain wet ink for a long period of time, the stamps are a constant source of trouble and irritation due to soiling of lingers, clothing and other items which might be placed in a desk drawer.

Quick drying inks have been available for many years for the printing and allied trades but these quick drying inks have been objectionable forhand stamping. Most iof the quick drying present day ink pads too rapidly. Quick inks use volatile solvents and the are such that the solvents evaporate drying ink requires frequent re`ink ing of the ink pad and repeated evaporation of the solvent with .the consequent deposit of solids the useful life of the pad.

As pointed out above the stamps themselves are frequently kept loose in a desk drawer where the stamping surface is subject to mechanical injury and wear. Thus the stamps have a needlessly short life and frequently give faulty impressions after a relatively short time.

I have found that these diculties of stamp and pad may be overcome by a simple unitary structure in which it is possible to use quick drying stamping inks and also to protect the pad and stamp from dirt and mechanical in the pad shortens Accordingly it is an important and basic object of the4 the ink on lthe stamp and pad remains It is another object of the invention to provide novel stamp and stamp pad `assemblies which may be sealed against evaporation during periods o'f non-use Iand which are at least partially sealed at all times except when the stamp is actually .being used to make an impression.

yA further-object 'of the invention is the provision of improved stamp pads in which the inking pad is flexible for easy insertion inand removal` from Vits container.

A still further object of the invention is to provide novel stamp and, stamp pad assemblies including containers which function to hold the stamps when not in use and keep them inked yor in (a position ready for inking.

A more specifi-c object of the invention is to provide novel marking devices comprising unit structures consisting of a transparent container of substantial volume having a sponge-like ink` pad in the bottom thereof and a sealing closure member forthe container carrying a stamping member m-ovably mounted relative thereto.

These and otherobjects and advantagesof the invention will be apparent to lthose conversant with the art from a reading of thefollowing description of certain exemplary embodiments thereof in conjunction with the subjoined claims and the annexed drawings in which:

Figure l is a central vertical section of a stamp and stamp pad assembly accord-ing -to the principles ofthe invention; and

rFigures 2, 3, 4 and 5 are views similar to Figure 1 illustrating modified f-orms of construction.

Referring rst to Fig-ure l showing one embodiment of stamp and stamp pad assembly constructed in accordance with the present invention, 10 indicates a widemouthed container of substantial volume preferably formed tof transparent material such as glass, plastic or the like, impervious to attack by the solvents, vehicles and/ or dyes used in conventional marking inks. The container 10 is provided with a cylindrical neck portion l1 having segmental or fragmentary screw threads 12 so that a cover 14, having similar coasting threads may be ,releasably locked in place [on the containerby relative twisting of a few degrees. An annul-ar gasket 16 of resilient material such` as rubber lis disposed Within the cover vso as to engage and seal the container when the cover is tightened in place. Where the cover and/or containerare fabrica-ted of flexible material such as styrene plastic, a tight, tapered friction lit between the cover and container mayibe provided in lieu of threads or other positive fasteningsin which case it is possible to eliminate the lcylindrical neck portion 11, if desired, Iand form the container of uniform cross-section.

The inking pad 18 may be formed of natural sponge, sponge rubber, cellulose sponge or other natural or synthetic sponge-like material and is disposed on the bottom of the container. The pad is preferably of the same size and shape as the container bottom, the'characteristic resilience and deformability of such material permitting easy insertion and removal through the mouth or neck '11 of the container. The precise material of the inking pad is not critical 'butit is to be underst-oodthat the mate? rials mentioned above are preferred. For satisfactory results, the material must be soft, ilegible, resilient, highly-absorbent `and resistant to deterioration.

Cover 14 is formed with a` preferably centrally lo` Patented Jan. 22, i957 y The lower end of the spring abuts against the `top of cover 14 and normally urges the shaft 24 and associated elements upward. This upward movement is limited by means of a resilient'sealing washer or gasket A3,6' preferably .of soft rubberrzor similar material disposed around the shaft between the underside side of the cover and the upper surface of stamp block 26. v y

The lower end of block 2,6 is formed with a ange 37 and a -re'silient pad or cushion 38, mounting Yan indicia forming stamp 'plate 40, lis secured to the flange. The thickness of sealing washer 36 is such that whenthe cover is tightened on the container and shaft 24 is at the limit of itsupward movement, Vthe stamp plate 40 is raised somewhat above the surface of the inking pad and also in the upper position, the space between the upper surface of the cover and the lower surface of the knob is such that, the knob may be depressed sufficiently to bring `stamp plate .40 into `contact with the ink pad even when cover 14 is completely loosened.

It will be understood that, while the cover, shaft, knob, block assembly 14, 24, 30, 26 may be` assembled by inserting the shaft through the cover and gluing or otherwise substantially permanently aixing the knob and block, it is preferred that the knob and block be removably attached to the shaft 24 as, for example, by means of removable pins 41, in order toffacilitate disassembly in the event it isnecessary or desirable to repair or replace any of -the components.

The sponge pad 18 is saturated with a suitable marking fluid such as a quick drying in k and, with the parts disposed in their normal relative positions as shown in Figure l, the assembly is ready for instant use or storage, as may be desired. For storage, the cover 14 is twisted snugly on its associated threads bringing gasket 16 into sealing relation on the lip of the container while spring 34 compresses washer 36 into annular surface sealing contact with the underside of the cover and the top of the block 26. Thus, the container is completely sealed against the evaporation of ink from pad 1S. The color of the ink may be seen through `the transparent container and the indicia borne by the -stamp may be indicated -by a label, not shown, aiiixed to the container, cover, or the attop of knob 30.

vFor use, the cover is given a slight twist to disengage the segmental threads and suiiicient pressure is exerted on knob 30 (before or after loosening of the cover) to compress vspring 34 and -bring the stam-pplate into proper contact with the pad for inking, whereafter the impression is made in the customarymanner, the transparency of the cover facilitating the orientation and location of the imprint in any desired position, Subsequent inkings may be accomplished inthe same manner without tightening the cover.

A modified form of the invention is shownin Figure 2 wherein parts in common with the species of Figure 1 are designated with like reference numerals. In this form, cover 14 is formed with a centrally located, substantially cylindrical recess or depression 42 having the aperture 22. in the bottom thereof and adapted toi receive a flange 44 on the lower end of a bellows 46 of flexible, resilient, material such as rubber or neoprene. The bellows 46 is open at `its lower end to accommodate shaft 24, and terminates at its upper end in a socket 48 adapted snugly to receive the upper end of the shaft. .-A knob 50 has a recess 52 which ts snugly around socket 48 and the upper end of the shaft, to maintain -the knob, and the upper end of the shaft and `bellows in assembled relation although a bonding cement or other positive attachment means may be'used to augment the frictional engagement effected by the squeeze fit. The remaining structure and the operation ,of this form of construction is the same as in the species of Figure 1.

The bellows replaces and performs the functions of both spring 34 and sealing washer 36 `of Figure l and therefore the structure, including the bellows, is proportioned so that the'bellows is under a predetermined com- Vpression when the stamp Ablock 26 is in abutment with the underside of the cover 14. This precompression functions to maintain the stamp assembly in its uppermost position. The ange 44 may be bonded to the cover 14 with a suitable adhesive such as rubber cement or the like.

The bellows sealing construction may be employed in conjunction with the embodiment shown in Figure 1 in which case the flange 44 would bear on the at top surface of cover 14. and washer 36 could then be eliminated, if desired. Likewise, in the embodiment of Figure 2, a compression spring such as that shown in Figure 1 can be used in conjunction with or in place of the bellows and, in the latter case, a -resilient Washer such as 36 would be required between the block 26 and the underside of the depression 42 to seal around aperture 22.

In another modification of the invention, shown in Figure 3, the entire stamp assembly is enclosed within the container 10, and cover 14 serves also as the knob or handle for the stamp. In this ,form of construction, a guide member 54 having depending cylindrical walls 56 is iixedly secured to the underside of cover 14 by `means of a threaded bolt 58 which extends through and has its head countersunk Vin and tiush with the upper surface of the cover. A suitable bore 60 in the guide member passes the shank of bolt 58 which extends through and substantially beyond the lower end of cylindrical walls 56. A nut 62 threaded on bolt 58, secures the guide member against relative rotation and serves as a seat for one end of a compression spring 64.

A frame or block 66 of a stamp, indicated generally by reference numeral 68, has a cylindrical portion 70 slidably received Within the cylindrical walls 56 of guide member 54 and is formed witha ycentrally located well or socket 72 `accommodating the 'lower endof a spring 64 which normally Vurges the frame downwardly or away from the guide member. The lower end of bolt 5S extends through a suitable aperture 74 in the block which is enlarged at 76 to accommodate a nut 78 threaded on the bolt and locked by any suitable means such as jam nut 79.

In Vassembling the stamp andcover, ,guide member 54 is first secured to the cover vby means of bolt 58 and nut 62, whereafter spring 64 is placed in position and frame66 is pushed up into the guide member until the lower end of the bolt projects suiciently from the enlargement 76 to permit installation of nuts 78 and 79. When the stamp frame iis released, spring 64 will force it out of the bore to the extent permitted by abutment with nut 78.

By suitable adjustment of the nuts 78 Vand 79 relative to Ithe end of bolt S8, the extent to which stamp block 66 is forced out of the guide member V54 and into contact with the pad 18 by spring 64 may be varied to obtain proper inking of the stamp with the cover loose and prevent overinking when the cover is tightened down.

The lower end of frame 66 carries -a laterally anged portion which forms `the .backing -upon which stamp cushion 38 and stamp plate 40 are mounted, in the customary ,manner well known in .the art. :It `will be understood that in this, as Ain the previously described embodiments, the backing portion, stamp and cushion .may be of any desired shape.

In a marking device constructed according .to the last described form of the invention, :when :the cover is screwed down tightly, spring `64 maintains the type or other indicia forming means on plate 40 in light butifirm contact Iwith the inking pad so that the plate is properly inked, as fully explained in the ,description `of Figure ,1, and the stamp is ready for instant use. To makean impression, a slight ,(usually Lcounterclockwise) twist `of the cover 44disengages the segmental threads and permits rthe stamp` assembly lto -be lifted from the container. yIt is pointed l'out that, due to the novel Vconstruction employed for securing the stamp frame to the cover, the stamp does not turn on the inking pad while in contact therewith as the'. CVe'r is turnelmthswvihkilg`d accllflilt of ink on the edges of the type is prevented and wear on the pad minimized.

A further modification of the invention is shown in Figure 4, wherein 82 indicates a relatively shallow container having a base'ange 84 and a removable closure member 86. The container illustrated is rectangular but it will be understood that various other shapes may be employed.

While the container may be fabricated of any suitable material such as metal or plastic, it is essential that the cover be made of resilient material such as thin metal or, preferably a transparent plastic.

The thickness of the upper, outer marginal portion of the side walls of the container is preferably reduced as at 88 to define a continuous shoulder 90 extending around the perimeter of the container, the reduced portion preferably having a slight taper as shown and exaggerated in the drawing for sake of clarity. Cover member 86 has side walls 92, depending from the margins of a at top section 94; the inner surfaces of walls 92 are substantially perpendicular to fiat section 94 and adapted to be wedged outwardly by the tapering lip portion 88 of the container walls. Thus, due to the resiliency and slightly extensible characteristics of the plastic material preferably used for cover 86, firm downward pressure on the cover will effectivelyhermetically seal the container, the shoulder 90 acting as a stop to prevent the cover from being wedged on the container so tightly that removal may be dii cult or inconvenient.

A stamp, shown generally at 96 and including a at rigid backing member 98 carrying on its underside a cushion 100 and type or other indicia forming means 102, is secured to the central portion of the fiat section 94 of cover 86 as by means of a stud bolt 104 opstanding from the upper surface of member 98, extending through a spacer member 106 and cover 86 and threaded into a suitable bushing in knob 108. The axial length of spacer 106 is selected so that, with the knob threaded securely on stud bolt 104 and the cover 86 in position on the container, the indicia forming means is slightly spaced from or just barely touching the surface of an inking pad 110 disposed in the bottom of the container. Itis pointed out that the spacer may be omitted in cases where the proportions of the container, pad, stamp and cover permit.

From the structure described it will be understood that, due to the flexible characteristic of the cover, downward pressure on knob 108 will cause the cover to flex and the indicia forming means to contact the pad for inking whereafter the stamp and cover are removed to make an impression in the conventional manner, the transparency of the cover facilitating the location and orientation of the impression to be made.

The taper on the lip of the container is sutiicient to prevent the cover from being tightly wedged on the container when the knob is depressed so that the inking procedure may be carried on without the necessity of holding the container down while removing the cover. When the stamp will not be used for some time, direct pressure around the marginal edges of the cover seals it to the container. The flange 84 on the base of the container allows the user to hold the container down while removing the cover without soiling his hands on the inking pad or the stamp.

A still further modification of the invention is shown fragmentally in Figure 5, wherein like reference numerals indicate the elements in common with previously described forms of construction. In this embodiment cover 14 is provided with a large, circular, centrally-located aperture 110 accommodating the insertion of an annular sealing boot 112 of U-shaped cross-section formed of exible, resilient material such as rubber, neoprene, or the like. v

The periphery of boot 112 is of a diameter very slightly larger than aperture .and -issformed with a pair of vertically spaced, continuous, peripheral lips`114 and 116 overlying the' upper and lower surfaces of cover 14 aroundthe margins ofthe aperture. Thus, when installed, the outer circumference of the boot is effectively sealed to the cover without bonding but it will be `understood that the boot may be bonded to the cover by vulcanization or with a suitable adhesive if desired. Adjacent the lower lip 116, boot 112 is thickened to form a reinforcing bead 118 which lends a degree of rigidity to the boot to keep it snugly in place and increase the sealing pressure against the inner edge of aperture 110.

The inner circumference of boot 112 is likewise formed with a thickened bead portion 120 adapted to snugly receive shaft 24 of a stamp assembly 122. It will be appreciated that while rod 24 may be pushed through sealing bead 120, the fit of the bead on the rod is snug and in conjunction with the friction characteristics of the boot material, prevents easy sliding and therefore, once the rod is axially positioned in the bead so as to bring the indicia forming means of the stamp assembly within proper distance of the inking pad 18, it will retain such position under normal usage.

Operation of the stamping unit is the same as described above for the embodiments of Figures l, 2 and 4. The U-shape section of the boot provides a highly flexible and resilient combination spring and seal, allowing ample axial movement of the stamp assembly 122, under relatively light operating pressure, to contact the sponge 18 whether the cover is loose or tight.

From the foregoing description it will be apparent that the present invention provides self-contained, unit marking devices providing for hand stamp inking which are compact, easy to store and ready to use and in which the need for a separate stamp rack is eliminated; evaporation of ink and the resultant odor is prevented; the use of quick drying volatile inks is made possible; pad and stamp contamination due to drying or caking of ink and the accumulation of dust, lint, etc., is averted, and the danger of soiling hands, clothes, papers and the like is reduced to a minimum.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A marking device comprising an open topped container, a stamp pad positioned in the bottom of the container to hold a supply of marking uid, a cap for said container, cooperating means on said cap and container for releasably securing said cap to said container in gas tight relation, an indicia carrying stamp disposed Within said container and below the lower edge of said cap, handle means carrying said stamp and extending through the cap for moving the stamp into and out of engagement with said pad, and a flexible member attached to said handle means and to said cap to form a gas tight seal therebetween which remains unbroken during use of said stamp, said flexible member being yieldable to permit movement of said stamp into contact with said pad.

2. A marking device as set out in claim 1 wherein said flexible member urges said handle means and stamp away from said pad.

3. A marking device as set out in claim 1 wherein said exible member extends above the uppermost portion of -said cap.

(References on following page) R'efere'nes Cited iii the le f Vt'lnispatemt UNITED STATES' PATENTS Ludewigs ocr. 9, 1934 Johnsn et al. May 19, 1936 Rbl Feb. 22, 1938 Wiswell Mar. 11, 1941 liger- L4-; Fel.V 5, 1952 FORIG'N PATENTS Y Geat ritain Sept. '9, 1,874

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