IMPROVEMENTS IN INDIA RUBBER STAMPS
Year: 1884

page_text: COMPLETE SPECIFICATION.
We FREDERICK BADDELEY and WILLIAM JOHN REYNOLDS, both of 19 & 20 Old
Bailey in the City of London, Indiarubber stamp Manufacturers, do hereby declare
the nature of our said Invention for "IMPROVEMENTS IN INDIA RUBBER STAMPS"
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:—
This invention relates to improvements in India Rubber Dating and Numbering
Stamps or India Rubber Stamps in which any moveable pieces are used to change
one or more of the parts of such stamps only.
In previous inventions of this kind the following faults have been observed to a
greater or less degree according to the care that has been used.
1 The several pieces may not be perfectly uniform in depth, with the result
that while some of the pieces mark clearly others give either a faint impression or
none at all.
2ndly The words or figures may not be accurately in line, and the impression
given is of an irregular and broken character. The practical difficulties in fitting
India Rubber in small pieces to metal work are so great that almost all stamps fail
in this respect.
3rdly When India Rubber is attached to a metal body by any process of
cementing there is a constant liability for the small pieces to become detached and
lost. This method of mounting moreover is not capable of any degree of precision.
4thly When the defects are sought to be remedied by making the whole of the
loose pieces in India Rubber other defects are observed such as liability to dis-
tortion, which large blocks of India Rubber exhibit-The necessity of turning
about pieces of Rubber in the fingers, while saturated with ink, to read the lettering
or place them in the stamp is always a great objection to this kind of changeable
date stamp.
Now the object of our invention is to obviate these defects and at the same time
facilitate the manufacture And in order that our said invention may be under-
stood reference is hereby made to the accompanying drawings.
To make the pieces forming the moveable dates figures or words we prepare a
steel mould similar to those used in type founding but of such a form as to deliver
a T shaped casting consisting of a body with an enlarged flange on the upper part
as shown in section in Figure 1. Upon the upper surface of the flange is cast the

page_text: figure or word which it is intended to affix to the underside in India Rubber, as
shewn in Figs 3 and 4. This forms an index and avoids the necessity of turning
the pieces and reading the reverse letters. All the different pieces required may
be cast in one mould by inserting different matrices with the words or figures
required engraved thereon. We form these words or figures in raised characters
in a sunk panel so that the words or figures may not be injured by the process
about to be described. The lower part of the type piece we form into a "dove-
tail" projection as shewn in Figs 1. 4 and 5 by inserting suitably shaped pieces in
the steel mould-The runner by which the mould is filled enters at the centre of
such projection. When the pieces are cast in type-metal or any metal or alloy that
can be cast in a steel mould we drill small holes across the narrow part of the type
as shown at in Fig 2 and by the dotted lines at x in Fig 1. The pieces are then
ready for attaching the rubber faces which we accomplish in the following manner-
Having prepared a sufficient number of letters and figures in metal resembling
printers type as shewn in perspective in Fig 6 but with the characters in intaglio
instead of in relief we arrange them in a "chase" or moulding frame shown in
section at T in Fig 5 placing them between parallel bars of steel D D and forcing
them closely together with a set screw E working in the block C; the other (end)
block C taking the thrust until they form one compact mass.
Having laid a strip of India Rubber prepared for vulcanizing upon the sunk
characters in the mould we place the flanged pieces F between the steel bar DD
with the dovetailed projection, rosting upon the upper surfaces of the India Rubber,
observing that the characters cast upon the flanges correspond with those imime-
diately below. The mould being completely filled we place it in a press part of
the top and under platens of which are shown at PP Fig 5, which press we heat
to the vulcanizing temperature At the same time pressure is applied until the
metal flanges of the pieces are closely in contact with the tops of the steel bars as
shewn in section in Fig. 5. The heat and pressure are continued until the India
Rubber is thoroughly vulcanized-During this process the India Rubber is forced
into the sunk letters or figures and also into the grooves in the type above, whence
it flows through the small holes x, above referred to uniting in one mass in the
centre To secure greater adhesion we treat the upper surface of the India Rubber
strips with a solvent, such as Benzole or any of the hydro-carbons or other fluids
in which India Rubber is soluble-When the vulcanizing process is complete we
remove the mould from the press and lift out the flanged pieces with the rubber
face adhering to them. We then part off the separate pieces with a thin knife
and they are ready for use in the stamp.
With these pieces formed as described we use a mount of the following descrip-
tion First, we make a die plate A Figs 7. 8. 9. 10 and 11 to take the permanent
part of the stamp, if any be required. If nothing else but the moveable date is
required we make it of sufficient dimensions to take the moveable pieces only-In
any case the die plate A is slotted to receive the date or other moveable pieces
and one end is thickened to form a hinge at B the opposite end I being grooved to
form a catch as shown in Figs. 7. 8 and 9 where the configuration of this part is
clearly seen. This plate is united by means of a hinge to a casting O' made in a
box forin and consisting of two chambers, the lower one being open at the bottom
and both ends the upper one being open at one end only. On the top of this
casting C¹ is formed a tang d upon which a suitable handle is driven or screwed.
Into the open end of C¹ a plate D' is fitted, hinged at the top and the lower inside
end is formed into a catch or hook H of suitable form to engage in the groove I
in the die plate A The purpose of this catch is to lock the die plate containing
the T shape moveable type to the upper part of the stamp-This Catch is kept in
the groove by a small arm K cast upon the catch plate carrying a spring L which
is so arranged as to press the arm K upwards. The arm is allowed a small vertical
movement in the upper chamber of the box; sufficient in extent to permit the
catch to be released when necessary as clearly shewn in Figs. 9. 10 and 11 where A
is the die plate hinged at B to the box C¹ the spring catch endlosing the open end.

page_text: being shown at D'. To enable the catch to be released at pleasure we form a
projection on the catch plate as shewn at El in Fig. 10 which catch protrudes
a short distance through a notch in the side of the holder and can be readily moved
by the thumb while the hand grasps the handle, A knob may be screwed into or
formed upon the hinged catch plate or the catch plate may be prolonged above the
hinge for the same purpose or any other simple means of enabling the catch to be
opened at will may be adopted as we do not confine ourselves to any one method
of opening the same.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is :-
1 The manufacture and use of flanged metal type having the precise nature of
the stamp indicated in the T head substantially as and for the purposes herein-
before described and shewn on the drawings Figs 1. 2 3. 4. 5 and 11.
2 The method and means of attaching the india rubber faces to the metal type
substantially as and for the purposes hereinbefore described and shown on the
drawings.
3 The method and means of forming type holders substantially as and for
the purposes hereinbefore described and shown in Figs 7, 8. 9. 10 and 11 of the
drawings.
4 The general arrangement and combination of the several and respective parts
together forming our improvements in India Rubber Stamps substantially as
hereinbefore described and shewn on the drawings.
100A