US2939390A - Shifting ink pad for self inking stampers - Google Patents

Description

June 7, 1960 Filed June 3, 1959 P. L. CLAUSING SHIFTING INK PAD FOR SELF INKING STAMPERS 2 Sheets-Sheet 1 WJNVENTOR.

BY Fad Z. Wa l g June 7, 1960 P. 1... CLAUSING 2,939,390

SHIFTING INK PAD FOR SELF INKING STAMPERS Filed June 5, 1959 2 Sheets-Sheet 2 INVENTOR.

III-w United States Patent 2,939,390 surname PAD FOR SELF INKING STAMPERS Paul L. Clausing 551 Hamilton St., Ottumwa, Iowa Filed June 3, 959, set. No. 817,784

8 Claims. c1. 101-334 My invention relates to improvements in self-inking,

tumbler type Stampers for marking flat or approximately flat surfaces. Such stampers ordinarily comprise a plurality of parallel type-bearing strips mounted for individual adjustment about a central carrier. This carrier is frequently called a tumbler because it is so mounted as to reverse itself endwise each time the stamp is used in order that oneach stroke the type may be first brought into contact with an inking pad at the top of the cage in which the tumbler is mounted, and then be exposed at the bottom of this cage so that it may be pressed against the surface to be marked. The common fault of existing self-inking stampers of this type is that the individual type on each strip always come into contact with exactly the samespot on the inking pad at each stroke. Because the inking pad is made of a spongy or felt like material in order to be ink absorbent, this material rapidly becomes compressed and packed at the particular points at which it is repeatedly struck by the type on each strip. Thisflis known as pattem packing. Since the type is usually spring. pressed against the ink pad when the stamper is not in use, this packing can occur while the stamper is on the dealers shelves, before the stamper is even used.. Once it has been so compressed, the pad will no longer absorb ink at these points and feed it properlyto the type. While the greaterpart of the pad, which does not come into contact with the type, may still be absorbent, the pad is useless, and must be replaced.

, While it would be possible to mount the inking pad on a cylinder. and gear this cylinder to the tumbler so that the pad would rotatetherewith, the gearing would involve considerable additional expense, and the type would then merely pack a plurality of points on the pad, distributed in rings about. the cylinder, for once a revolution of the cylinder had been completed each successive type contact would be made at the exact spot at which a type contact had been made on the previous revolution.

' I have found, however, that if the ink pad is made in the form of a disc, and loosely mounted in a cage so that it can dance about the'rein as the stamper is used, it will tend to rotate and slide in such a random manner that virtually its entire surface will be contacted by the type, thus preventing packing at any one point, or even at a plurality of frequently used points. This arrangement is thus not only chaper, but much more eifective than a cylindrical mounting for the inking pad.

The object of my invention is therefore to provide a rotatable inking pad for a self-inking tumbler type stamper and means for loosely mounting it in a suitable cage for free random movement therewithin. Advantageously, the pad should also be readily removable for replacement.

One specific embodiment of my invention will now be described in conjunction with the following drawings in which:

Fig. 1 is a side view showing my new stamper;

Fig. 2 is a front view of the stamper;

Patented June 7, 1960 Fig. 3 is a partial vertical section taken along the line III-HI of Fig. 2;

Fig. 4 is a horizontal section taken along the line IVIV of Fig. l;

Fig. 5 is a perspective view of my stamper;

Fig. 6 is a partially exploded view of my stamper, with the tumbler actuating means broken away, showing how my inking pad is mounted in the stamper.

Like reference characters denote like parts throughout the several views.

Referring now to Figure 5, it will be seen that my stamper comprises a conventional lower frame or cage 10 provided with an opening 11 at its lower end through which the type is projected for stamping, and the customary rubber pads 9 to prevent marring of any object upon which the stamper-is placed. A type carrier 12 is pivotally mounted in this cage to turn about the horizontal axis 13. The top of the frame 10 is formed by a cross-piece 14, on which the stem 15 is mounted. A hollow handle or plunger 16 is slidably mounted on the stem 15 and a fork 17 is fixed thereto. The two arms of this fork are adapted to slide on the vertical sides of the frame 10, and are slotted at 18 to receive pin 19, fixed to the type carrier 12, which extends through slots 20 in the vertical sides of the cage 10. These slots have semi-circular portions so that as the plunger 16 is pushed down, the pin 19 travels therein, and turn the type carrier 12 about the axis 13, before pressing the type against the surface to be stamped. A spring 21 (Fig. 3) automatically returns the type carrier to its original position when the plunger is released, and in that position the type contacts and is spring pressed against the inking pad 22 (Figs. 3, 4 and 6).

The position of each individual type bearing strip 23 may be adjusted to expose any desired character thereon by turning the particular knurled disc 23a associated therewith.

All of the mechanism thus far described is of a conventional nature, except for the inking pad 22 and its mounting. This pad consists of a disc of absorbent material 22a, such as felt or the like, embedded in a shallow cup 22b of a relatively ink proof and rigid material, such as metal.

The pad is loosely mounted in a cage formed by the crosspiece 14, portions of the vertical sides of the frame 10, and two identical clips 24 (seen best in Fig. 6). These clips each comprise a slightly resilient U-shaped vertical portion, a lower ledge 24a, and an upper ledge 2412. The two arms of the U-shaped portion are provided with outwardly projecting bosses '25 which snap into holes 26 in the vertical sides of the frame 10. These holes are formed by striking the metal of the side frames inwardly, thereby forming below the holes 26 small shelves 27 on which the lower edges of the clips 24' can rest. The upper ledges 24b of the clips fit into notches 28 in the cross-pieces and are supported thereon. The lower ledges 24a support the inking pad 22. The crosspiece 14 is provided with horizontally extending projections 29 which fit into mating slots in the side frames 10.

Between these projections 29 a longer tongue 30 is bent down and welded to the side frames 10. The vertical edges of this projection serve as stops for the clips 24 when they are inserted into the frame.

Attention is drawn to the clearances shown between the ink pad 22 and the sides and top of its cage respectively, which are best seen in Figs. 3 and 4. These are critical to the successful operation of the device. The first of these clearances must be sufiicient to permit the pad to shift horizontally the width between the type characters, but insuflicient to permit the pad to fall oif the ledges 24a. The clearance between the pad and the top of its cage, i.e. the cross-piece 14, is even more important.

r r QQQSQBQo I a space permit v theriv Fed to drop and bounce when Q the stamper handle is pushed'down to perform a stamping operation. When the stamper'is not in Ilsa-spring 21 tu s 2 p ea i to t upper r n rpa mQCtiHg P'O tion, and the distance between the bottom ofthe pad cage'and the axis of about which the type carrier is s shorter than that between this axis and theface of the 7 type which contacts the ink -pad sothat the ink pad is f d u Within i s case aadrg s dras in t o s-pi J14. "tWhen the stamper is in this position, there is then a space between the edgespf the pad and the supporting ledges 24a. 7 As illustratedin Fig. 3, thestamper handle ha's'been pushed down enough to remove the it-ype from ing, revolving efiect; Y Because of permitted; play,

'7 1 theink pad cannot possibly stop in exactly the same place each time, and, since the'shitting is not mechanicallYi-nwo trolled, but intensel to chance, there cari be no periodic repeating, Theink pad is round, so it'can and does rei rolv, biit it, does not revolve about 'any'e xact center. Consequently,- the ink pad, .in my invention, will not the nkr en, e amperi 'qp atedrthe ha is suddenly 'pnshed down, the type strip carriei '12 turned n f n n t t p uddenlyr a e away from t neath'the ink pad: Ihe inlg pad iloses ;its support and i drops to the ledges 72 4a, Since the'whole stamper is moving downward rapidly the'ink piadis, literally, thrown against'these ledges to produce a bouncing, shifting, dancspot pack or patternpae. The packin g is dis tribntjed ove'r'the entire pad, giving it many times longer life than rigidly'held ink ipads.

' It will be 'appreciated .t'ha' 't myihvention is not limited to the specific embodiment hreinbe fore describei but may be embodied in tnmbler ,typ stanipers differing therefrom: in structural details without thereby departing f jm the spirit 'of my invention asdefiiiea by the following claims. 7 g t a 7' a a 7 What I claim is:"

- frame ,toapply an indicia; said stamper being charac er- 1. Am -151st t peset-inking stsriipfegtheiimd csmprising a frame, an ink pad siipported on said frame, type carryin means: pivotally mounted said frame, and means for pivoting said type carrier from a first position in a V which thetype thereonis inkpad to a secondpo'si'tioiiiri' which said type ie-projected from said 7 frame to apply an ifidic'ia to a suitable snrf ace said stamperbeing charac'itei'iz'ed bythe fact that it comprises 'a cage extending transversely across saidframe in which s ink pad is ro't'atably enclosed said page having an s ring-m it"s 156mm passages to eceive said ty e but too small to said ink pad, the-inner dimensions of said cage in directions both transverse to and ilongit'udi- 3. A stamper as claimed in claim '1 in which the difference between the external dimensions of said ink pad and the internal dimensions of said cage in a direction transverse to said frame is at least as great as the transverse distance between the type on said carrier. 7

4. In combination an ink pad for a stamper and a cage in which said pad is iotatablygncltased, said cage having too small to pass said had,- as inner amas iis of said cage being substantially gleater than the jcorresppnding outer dimensions of said pad, and said ink'iiad being freely and rahdomly i'11ovable therein; 1 a

5 A Stamper as claimedjnclaim" 1 in which said frame comprises two vertical side idem ers and said cage coman opening in its bottom dimensioned to adm'tgtyp ebut prises a transversemember fixed the'rebetween'to constitnte the top of said cage, together with two opposed clip members provided with U-shaped portions'dime nsioned to fit between said side members and constitute the si of said cage, said'clips carrying. upper ledges positioned-and dimensioned to rest on said transverse member; and lower ledges adapted to support the edges-of said "ink pad and constitute two sides of said opening: k 1 7 a 6. A stamperasclaimed claim=5 in en's-sis clips are resilient and vthesarms of said U-shape'd portions batty catch means adapted to snap into engagement with mating means on said side members;

7; Av hand-operated tumbler type self-inking staifipei' of the kind comprising a frame; an ink pad suppo ed in said frame; type-carrying means pivotally inotlhted infsaid frame, andvmans for pivoting said ca'rriei" from iavposition in which 7 the type thereon is .in contact with said pad to a positionin which said type is projected from said said tYPQ-carrier is ,pivotedtbbririg said type into Contact with said'pafdr aidpad is liftedlofi the bottom of its age, and'when said typeigcarrier is-pivofed away fromsaid cage said padisdropped on thenbotto'in theredf to efiect a' nally of said frame being rsubsta'ntialiy greater than exlethal ons of said pa'd ins'aid directions, said inkpad being freely and randomly movable in all direc 'tions within the periphery of saidicage'; a

12. 'Alstamp'er as claimed in claim 1 inwhich said ink pad is circular,

random displacement thereof iirerscgcsa' in die as bf atent 210,286; a 232,145, 454,499 r,'142;24o'

V V Attcsting Officer UNITED STATES PATENT OFFIEE CERTIFICATE OF CORRECTION Patent Nee 2 939 39O June 7 1960 Paul Lo Clausing It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3 line 23 for "mechanicallyjnwo" read mechanically cen1-= Signed and sealed this let day cf November 19600 (SEAL) Attest:

KARL Ha AXLINE ROBERT C. WATSON Commissioner of Patents

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