Year: 1887

page_text: Date of Application, 3rd Dec., 1887
Complete Left, 22nd May, 1888
Complete Accepted, 22nd June, 1888
17

page_text: COMPLETE SPECIFICATION.
Improvements in Cameras.
1, VERNON WARBURTON DELVES-BROUGHTON, of Elsham Road, Kensington, Civil
Engineer, 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:
My Invention relates to photographic cameras, and has for its object to enable the
camera front to be elevated or depressed independently of the camera support so as to
incline the optical axis of the lens in a vertical plane whilst maintaining constant the
point of intersection of said axis with the sensitive plate and to enable the back of the
camera body in which the plate is contained to be swung on a horizontal axis in order
to bring it to the proper position after the lens has been so adjusted. For this purpose
the camera front is connected to the back by a pair of side bars acting as radius links
whose centre of motion is in line with the plane of the plate and with the point at
which the optical axis of the lens intersects such plane, the said centre of motion
being also the centre on which the camera back swings. The camera front is adjustable
along the said radius bars for the purpose of extending the camera body instead of
sliding along the base board as usual. The side bars may either be mounted on
horizontal pivots on which the whole camera would be adjustable or their front ends
may be supported by a vertical adjustment rising from a base board.
Figure 3 is
Reference is to be had to the drawing left with my Provisional Specification and to
the accompanying two additional sheets of drawings. Figure 1 is a part front
elevation, and figure 2 a side elevation, of one arrangement of camera.
a side elevation of a similar arrangement for studio use. Figure 4 shows detail views
of the means for clamping the front on the side bars. Figure 5 is a cross section,
and figure 6 a side view, of a rack motion for fine focussing by adjusting the camera
back upon the side bars. Figure 7 is a side elevation of a short focus camera in which
the side bars are supported by a base board. The same letters of reference indicate
the same parts in all the figures.
A are the radius bars pivoted at E to the sides of the camera back (in which the
dark slide or other plate holder is fitted in the usual way) the pivotal axis being in the
same plane with the sensitive surface and at the height of the central point thereof
where the optical axis of the lens intersects the plate. Dis the front of the usual
bellows body. It is provided with the usual transverse sliding adjustment in an outer
frame and this frame is fitted to slide along the lateral radius bars A, the plane of the
frame always remaining perpendicular to the length of the said bars. This adjust-
ment may be effected by a focussing pinion G. which extends across the frame and
gears into racks on the lower edges of the radius side bars A. These radius bars may
either be in one length or in two or more lengths jointed together by a rule joint,
so as to fold inwards across the front of the camera when collapsed.
In figures 1 and 2, the radius bars A are hung on horizontal trunnions B in a
stationary open rectangular frame by which the whole camera is supported on the
tripod stand. The camera is therefore free to be swung as a whole upon the
trunnions B in order to incline the optical axis of the lens, the camera after being so

page_text: adjusted being fixed by clamping screws C passing through the supporting frame and
through a slotted quadrant arm fixed to the radius bars A and having their slots
curved concentrically to the trunnions B. Instead of the quadrant slots, slotted struts
may be used. The swing back after being adjusted on its centres E is clamped in
position by binding screws F passing through slottod quadrant plates affixed to the
radius bars A.
Figure 3 shews the camera after adjustment. The camera here shewn is intended
for studio use and differs in the substitution of short brackets for the open rectangular
frame in which the side bars A are hung.
Referring now to figures 5 and 6, it will be seen that instead of fixing the bars A
rigidly to the quadrant plates H. they may be fitted to slide in guides / formed on
said plates and be adjusted each by means of a pinion I mounted on the plate H and
gearing with a rack on the bar A, in which case the pinion G and its racks would
be dispensed with, the front carrying frame D being then merely slid along and clamped
to the bars A by the clamping screws d, as shewn in figures 3 and 4, for roughly
focussing, the pinions I being used for fine adjustment. As shewn by the dotted lines
in figure, the camera may be adjusted independently of its support so as to elevate
or depress the optical axis of the lens without moving the point of intersection of such
axis from the centre of the plate.
In figure 7, the side bars A are not hung on trunnions but are supported at their
front ends by standards K. rising from the base board L, and provided with a vertical
adjustment by which the bars A, and consequently the camera front and lens may
be elevated and depressed, the back of the camera body being in this case hinged at t
to the base board and secured after adjustment by slotted struts M pivoted to the
base board and clamped to the back by screws. With this arrangement, it will be
observed that although in swinging the back on the hinges relatively to the base
hoard, the centres E on which it swings relatively to the lens, move backwards or
forwards, the focal distance of the lens is always maintained by the side bars A,
which together with the camera front and lens, move back and forth with the camera
back. In this arrangement, the front is provided with clips which slide along the
side bars A, and the lens mount slides telescopically through the front for fine
adjustment.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
1 claim is;
1. A photographic camera in which the camera front and back are adjustably
connected by radius bars pivoted to the swing back so as to permit of the optical axis
of the lens being inclined relatively to the plate whilst maintaining constant its point
of intersection therewith, substantially as herein set forth.
2. A photographic camera in which the camera front and back are connected by
radius bars pivoted to the swing back, the camera front being adjustable along the
said radius bars for the purposes of focussing, substantially as herein set forth.
3. A photographic camera in which the camera front and back are connected by
radius bars pivoted to the sides of the swing back upon centres whereon the back is
free to swing, the radius bars being mounted on horizontal trunnions whereon the
whole camera is adjustable in altitude independently of its support, substantially as,
and for the purpose, set forth.
V. W. DELVES-BROUGHTON.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.