AN IMPROVED PLATE-HOLDER' FOR PHOTOGRAPHIC AND OTHER PURPOSES
Year: 1856

page_text: LETTERS PATENT to John Avery, of 32, Essex Street, Strand, London,
Patent Agent, for the Invention of. "AN IMPROVED PLATE-HOLDER' FOR
PHOTOGRAPHIC AND OTHER PURPOSES."-A communication from Madame
Millot, of Sault-les-Rethel, France.
Sealed the 2nd January 1857, and dated the 12th July 1856.
PROVISIONAL SPECIFICATION left by the said John Avery at the Office
of the Commissioners of Patents, with his Petition, on the 12th July
1856.
I, JOHN AVERY, of 32, Essex Street, Strand, London, Patent Agent, do
hereby declare the nature of the said Invention for "AN IMPROVED 'PLATE-
HOLDER FOR PHOTOGRAPHIC AND OTHER PURPOSES," a communication, to be as
follows, reference being had to the annexed Drawing, which is a vertical
longitudinal section:-
A, steady rod; A', sliding hollow rod or case; B, B', jaws between which
the plate J is held; C, handle. The jaw B' is fixed on the sliding rod A', and
Bis fixed on a sliding piece in a recess in the handle C, and is operated upon.
by a spring R. G is a trigger, playing freely in a groove, and is united with
the sliding rod A' by a screw V, which plays in the mortice I, so that by
pressing the trigger, the jaw B slides back, and the plate is easily removed.
A screw E in the rod A adjusts the relative positions of the rods to fit any
size plate; for small plates, the rod A' being reversed, the jaw D will be used

page_text: the wall for support.
This apparatus is also applicable to other purposes in which plates are
required to be held so as not to be injured by handling, as in painting, gilding,
enamelling, varnishing, and such like operations.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Avery in the Great Seal Patent Office on the 10th
January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
AVERY, of 32, Essex Street, Strand, London, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the 12th day of July, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Avery, Her special licence that I, the said John Avery, my executors,
administrators, and assigns, or such others as I, the said John Avery, mý
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED PLATE-HOLDER
FOR PHOTOGRAPHIC AND OTHER PURPOSES," a communication from Madame Millot,
of Sault-les-Rethel, France, upon the condition (amongst others) that. I, the
said John Avery, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Avery, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement :-
In photographic operations the glass plates are covered or prepared,
according to the process followed, with a thin layer of collodion, albumen, or

page_text: various solutions of salts, in order to render them more sensitive and fit
for receiving or retaining the representations, of objects of which copies are
required. In order to cover the plates with liquids or solutions which cannot
be well spread over with a brush, because it would leave a streaky surface, and
the coatings being uneven the impression would not be good, the liquids
or solutions must be poured in small quantities at once on the plate, which is
to be inclined in all directions, so as to have the surface well and evenly
covered; the surplus which does not adhere to the plate is run off at one
of the corners. Formerly, to effect this coating of the plate and pouring off the
surplus liquid, the plate had to be held with the fingers applied at the edges,
with great care not to touch the surface, which had the two-fold disadvantage
of leaving spots on the plate, and liable to burn the skin of the fingers when
corrosive solutions were used. Several kinds of plate-holders have already been
used in order to avoid touching the plate, but they are not convenient, as they
hold the plate only near the corners with pins, and which would allow it
to fall off if turned upside down, and is not serviceable for heating the plate.
The plate-holder which is represented on the annexed Drawing, and is to be
described, if free from such disadvantages.
Figure 1 is a longitudinal vertical section; Fig. 2, a plan; and Fig. 3, an
under view of part of the stock, showing the mechanism.
A, fixed rod of wood or other suitable material; A', adjustable hollow rod,
fitting on the first one as a sheath; both rods are provided with jaws or clamps
B&B', cut aslant or hollowed on the parts opposite to each other. The plate
J, represented in red lines on Fig. 1, is placed between the jaws B & B', which
hold it steady while the surface is being operated upon. The jaw B' is fixed
on the moveable rod A', whilst the jaw B forms the end of a sliding piece
or carriage, shown in side view and plan, Figs. 4 & 5; the sliding piece is
impelled by a spring R, and is moveable at pleasure in three directions. C,
stock or handle of the holder, to be held in one hand when operating with the
other, allowing a convenient change of position for spreading the solution
on the plate. The jaw B' is motionless, as already stated, whilst the jaw B can
be moved to and fro, being worked by the finger bearing on the trigger G,
which projects underneath; this trigger, shown separately in front view, Fig. 6,
is fastened to the slide of the jaw B, Figs. 4 & 5; the screw V, which connects
these two pieces, plays in a mortice I, cut through the stock C, and forces the
slide B to move forth or back when the trigger is operated by the finger. The
spiral spring R, placed in a recess of the stock, impels the slider B forward,.
whilst the finger bearing on the trigger G pulls it backwards when required.
The jaw of the slider B, by the action of the spring R, bears constantly on the

page_text: plate J, which is thus held fast between both jaws. The slider B is guided in
its to-and-fro motion by the screw V playing within the mortice I, 'and by the
gudgeon a, which plays in a hole h, bored into the stock, so as to allow the jaw
to hold the plate firmly. A covering of horn, hardened caoutchouc, gutta
percha, or other suitable substance, as shown, Fig. 1, is fastened on the upper
face of the stock, covering also the slider B and spring R, to protect them from
corrosive substances; the head of the screw V is likewise protected by a little
screwed stopper b, Fig. 1, for the same purpose. The slider B and stock C are
cut slanting, as seen at d, d, Fig. 4, so as to form kinds of gutters-for running
off the surplus of the solution that has been spread over the plate, and to pour
it back into a vessel. The sheath or rod A' is capable of being shifted and
-fixed at several different positions on the inner rod A, according to the size of
the plates to be prepared; it is made fast at its right place by the set screw E.
For smaller plates, the rod A' can be turned upside down; in that case the
plate should be held by the jaw D, Fig. 1, instead of the jaw B', which would
be underneath. The inner rod A can be made either of wood, as the stock C,
or of metal and hollow, as the covering one A'; in the first instance the
setting screw E would be a wood screw, in the second instance it should have
threads fit for screwing in metals; and if applying a hollow inner rod, the
spring R pushing the slider B forward, should be replaced either by a similar
one, P, Fig. 7, or a caoutchouc one, fixed at one end inside of the rod A, and
at the other end on the screw V; this spring P would then exert a pulling
action.
For preparing the plates, they are first placed between the jaws B & B', as
seen at J, Fig. 1; the plate-holder is taken hold of with one hand at C, the
required solution is then poured in small quantity over the plate, as before
stated. By the peculiar arrangement of the apparatus motion can be easily
given to the plate, in order to spread the solution regularly over it and to
avoid the streakyness which would be often produced by collodion or other
similar substance if this were not to be observed.
In order to prepare plates of larger size, which could not be maintained by
hand on account of their weight, and which could not receive the required
oscillating motion, there is a point e, made of silver or any other suitable
metal, which, being stuck either in the wall or a door, supports the apparatus
to give the required motion to the plate.
My improved plate-holder being now 'described, I wish to have it well
understood that I do not mean to confine myself to the precise details which
have been herein set forth, and illustrated on the annexed Drawing, as the
component parts may be modified according to the requirements; for instance,

page_text: various kinds of springs may be used, or a magnet or other suitable con-
trivance instead of springs may be used, provided I succeed in fulfilling the
purpose of the Invention, which consists, as aforesaid, in maintaining in a
suitable manner the plates used for photographic operations for preparing them,
as well as any other plates which should be held without being touched by the
fingers, for painting, gilding, hot varnishing, &c., as herein explained.
In witness whereof, I, the said John Avery, have hereunto set my
hand and seal, this 10th day of January, in the year of our Lord
One thousand eight hundred and fifty-seven.
JOHN AVERY. (L.B.)