Improvements in Turn-tables for use with Photographic Cameras and for other purposes.
Year: 1890

page_text: Date of Application, 31st July, 1890
Complete Specification Left, 30th Apr., 1891-Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in Turn-tables for use with Photographic Cameras
and for other purposes.
I, JOHN HENRY SKINNER, trading as J. H. Skimmer & Co. of East Dereham,
in the County of Norfolk, Photographic Apparatus Manufacturers, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to produce a turntable having means whereby it
can be readily adjusted in any position. The invention is therefore specially
applicable for attachment to the base board of an ordinary photographic camera,
but may be used for other purposes where an adjustable turntable is required.
According to this invention 1 provide the base to which the turntable is to be
applied, with flanges or with plates affixed above and below so as to form an
annular space for the turntable to revolve in. To the outer edge of the turntable
I aflix a metal ring split or with a V piece cut away.
Within this split or V
I place a loose truncated pyramidical block or wedge having a screw passing
through its centre, the said screw being provided with suitable means for rotating
the same.
The wedge is prevented by the split or V from turning and thus acts as
a nut the rotation of the screw will therefore cause the wedge to travel towards
or away from the centre of the turntable. As the wedge travels towards the
centre it will expand the split or V and cause the ring to bind tightly on the outer
edge, and thus renders the turntable fast. When the wedge travels away from
the centre, the ring is set free and permits the turntable to revolve.
2
1000
CASTLE SMITH,
Invention Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.
COMPLETE
SPECIFICATION.
1
Improvements in Turn-tables for use with Photographic Cameras
and for other purposes.
1, JOHN HENRY SKINNER, trading as J. H. Skinner & Co. of East Dereham,
in the County of Norfolk, Photographic Apparatus Manufacturers, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to produce a turn-table having means whereby it
can be readily adjusted in any position. The invention is therefore specially
applicable for attachment to the base board of an ordinary photographic camera,
but may be used for other purposes where an adjustable turn-table is required.
In the accompanying drawings Figure 1 shews a plan of a camera' base-board to
which my invention is applied; Figure 2 is a similar view with the upper flange or
ring plate A removed; Figure 3 is a section on the line X X Figure 1; and
Figures 4 and 5 shew enlarged details of construction.
In carrying my invention into practice 1 provide the base-board C or other
the base to which the turn-table is to be applied, with ring flanges or with
plates A and B rigidly affixed in any suitable manner on the edge of the
circular aperture in which the turn-table is to be fitted. These ring flanges
or plates A and B are secured one on the top and the other on the bottom of the
base C in such manner as to overlap the edge of the circular aperture already

page_text: referred to, and thus provide an annular space between them in which the turn-
table can rotate.
To the outer edge of the turn-table I affix a metal ring D split or with a
V-shaped piece cut away therefrom, as shewn at E Figures 2 and 4. Within this
split or V-shaped aperture E 1 place a loose truncated pyramidical block or
wedge F through the longitudinal axis of which is tapped a female thread
through which the male screw G passes, as shewn in Figures 4 and 5. The inner
end of this screw G is provided with a suitable handle H the outer edge being
burred over so as to prevent the screw being completely withdrawn from the block
or wedge F. The split or V-shaped aperture E in the ring being flat in cross
section will prevent the block or wedge F from turning and will thus cause it to
act as a nut; the rotation of the screw G will therefore cause the block or
wedge to travel towards, or away from the centre of the turn-table. The
drawings (Figures 2 and 5) shew the ring with a V-shaped aperture converging
towards the centre of the turn-table, and the block or wedge F is correspondingly
converging. It therefore follows that as the block or wedge F is caused to travel
towards the centre of the turn-table it will expand the V-shaped aperture E and
will thus increase the diameter of the ring D and cause it to bind tightly on its
outer edge against the interior of the circular aperture in the base C thereby
holding the turn-table fast; but when the block or wedge F travels away from the
centre of the turn-table the ring D is set free and permits the turn-table
to be revolved in the annular space formed between the ring flanges or
plates A. and B.
As a modified form of my invention the V-shaped aperture E in the ring D and
the wedge or block F may be made to converge away from the centre of the turn-
table in which case the ring will be expanded as the wedge or block is caused to
travel away from the centre of the turn-table and cice versa. It will also be
obvious that the rotation of the screw G may be effected from the outside of the
ring D instead of from the inside as shewn in the drawings.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is-
(1) The adjustable turn-table herein described consisting of a split or cut ring
expansible by means of a wedge or block actuated by a screw substantially
as and for the purpose hereinbefore set forth and illustrated in the accompanying
drawings.
(2) In a turn-table for use with photographic cameras and for other purposes,
the means herein described for readily adjusting a turn-table in any position
substantially as set forth.
Dated this 28th day of April 1891.
CASTLE SMITH,
"Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.