US972359A

US972359A - Rubber stamp.

Info

Publication number: US972359A
Application number: US53564309A
Authority: US
Inventors: Calder C Gibson
Original assignee: Individual
Current assignee: Individual
Priority date: 1909-12-30
Filing date: 1909-12-30
Publication date: 1910-10-11
Anticipated expiration: 1927-10-11

Description

G G. GIBSON. RUBBER STAMP.

APPLIOATION FILED 111:0. so, 1909.

Patented Oct. 11,1910.

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"UNITED STATES PATENT OFFICE.

CALDER C. GIBSON, OF BUFFALO, NEW YORK.

RUBBER STAMP.

To all whom it may concern:

3e it known that I, CALIiER C. GIBSON, a citlzen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented a certain new and useful Improvement in Rubber Stamps, of which the followin is a specification.

This invention relates to improvements in rubber stamps and particularly to the construction of the cushion or base located between the block or support and the type strip.

The principal objects of the invention are to secure a very soft and resilient cushion and to enable cushions of a desired size to be readily cut from a cushion strip or sheet. Toaccomplish these objects the rubber strip or sheet from which the cushions are cut is formed of two superimposed sheets of rubber of differing quality vulcanized together to form an integral structure, one of said sheets being of very soft porous or honeycombed rubber, known to the trade as sponge rubberand the other being of the ordinary commercial quality non-porous rubber. The sponge rubber sheet is cut into a series of blocks by a series of thin blades arranged so as to out both longitudinally extending and transversely extending grooves therein. The sheet of ordinary rubber is pro-vided with a series of recesses or pockets which are formed therein in the outer surface thereof during the process of vulcanizing the two sheets to gether and are sufficiently deep to extend up Within the sponge rubber sheet.

The invention also relates to certain details of construction of the cushion or base strip, which will be hereinafter described and perhaps claimed reference being had to the accompanying drawings in which,

Figure 1 is an end View of a hand stamp partially in section provided with the improved cushion or base. Fig. 2 is a detached top view of the cushion or base. Fig. 3 is a detached bottom View of the cushion or base. Fig. at is a transverse section on line a a, Fig. 2. Fig. 5 is a transverse section on line b b, Fig. 2.

In referring to the drawings in detail like numerals designate like parts.

In Fig. 1 a hand rubber stamp is shown having a Wooden supporting block 1 provided with a handle 2. The bottom surface of the block 1 is recessed to secure a cushion or base for the stamp proper which is se- Specification of Letters Patent.

Application filed December 30, 1909.

Patented Oct. 11, 1910.

Serial No. 535,643.

cured therein by cement or in any other suitable way.

The cushion or base is constructed so as to provide a very soft and resilient cushioning effect to take care of any slight inequalities of surface in the article to be printed upon and also to receive an independent pneumatic cushion to supplement the action of the resilient cushion.

The soft resilient cushioning effect is obtained by utilizing a fairly thick outer sheet of exceedingly soft porous or honeycombed rubber known as sponge rubber, and the inner pneumatic action is secured by attaching to the under surface of the sponge rubber a sheet of ordinary non-porous rubber. These two sheets are vulcanized together to form an integral sheet and at the same time are pressed into form between dies which also cut the sponge rubber portions in blocks and form recesses or pockets in the ordinary rubber.

The sponge rubber portion is indicated in the figures of the drawings by the numeral 3, and the ordinary rubber portion by the numeral 4.

By referring to Figs. 4 and 5, it will be noted that the indentations or grooves 5 which separate the sponge rubber portion 3 into blocks extend completely through the same, so that the sponge rubber is actually completely separated into a plurality of parts which are only held together by the vulcanization of their side surface to the ordinary rubber portion 4. The advantage of this is that it is not necessary to cut the sponge rubber at all in cutting a base of any desired size.

The pockets 6 in the ordinary rubber which may be of any desired shape or depth are formed therein during the process of vulcanization and force the ordinary rubber up into the songe rubber securing an interlocking eifdct which provides more surface for vulcanization and secures the two sheets inseparably together.

WVhen the base is secured in place in the stamp support or block 1, as shown in Fig. 1, the pockets provide a series of air spaces which form inner pneumatic cushioning means. a

In the adaptation of the invention shown in the accompanying drawings, the indentations or grooves are cut through the sponge rubber on one side of the base sheet and the pockets 6 are formed in the ordinary rubber 'on the opposite side of the sheet and are so sized, shaped and located that each pocket extends within one of the blocks formed by the indentations or grooves. By this means each block has an outer very soft resilient cushion of sponge rubber and an inner pneumatic or air cushion located behind the sponge rubber which gives a double cushioning effect.

A rubber type plate 7, having formed thereon the desired printing matter, is secured by cement to the outer face of the sponge rubber as shown in Fig. 1. The ordinary rubber sheet is thinner than the sponge rubber sheet, being in the adaptation shown about one fifth of the total thickness of the completed cushion, and when pressed into shape is of an alveolated form owing to the multiplicity of its pockets. To cut a base of the desired size from this improved sheet, it is only necessary to cut through the ordinary rubber, which can be out easily and accurately with a wet knife, placing the knife in the bottom of the grooves 5 which extend completely through the sponge rubber.

The great advantage of this improved form of cushion base sheet is that the easy soft resiliency of the sponge rubber is secured together with the desirable pneumatic action of air pockets.

I claim.

1. In a device of the class described, a

cushion composed of superimposed sheets of sponge rubber and ordinary rubber vulcanized together to form an integral structure; one of said sheets being formed with grooves which completely sever the sheets into separate sections and the other of said sheets being formed with recesses which extend beyond the bottom of the groove and into the sections of the first mentioned sheet.

2. In a device of the class described, a support, a cushion secured to said support and having an outer portion of soft porous rubber known as sponge rubber; said outer portion being divided by longitudinal and transverse grooves into blocks, and an inner portion of ordinary rubber provided with recesses forming air pockets; each of said recesses extending into one of the blocks of the outer portion, and a type plate secured to the outer surface of the outer plate.

3. In a device of the class described, a cushion composed of vulcanized together sheets of sponge rubber and non-porous rubber; one of said sheets being provided with dividing imlentations which extend to the surface of the other sheet and the other of said sheets being provided with pockets which extend into the first mentioned sheet between the indentations thereof.

CALDER c. "oIBsoN.

Witnesses L. M. SANGSTER, Gnonon A. NEUBAUER.