Improvements in Photographic Cameras.
Year: 1887

page_text: Date of Application, 23rd May, 1887
Complete Left, 22nd Feb., 1888
Complete Accepted, 23rd Mar., 1888
PROVISIONAL SPECIFICATION.
Improvements in Photographic Cameras.
I, THOMAS PRESCOTT, of Arcade Chambers, St. Mary's Gate, Manchester, in the
County of Lancaster, Mechanical Engineer, do hereby declare the nature of my
invention for IMPROVEMENTS IN PHOTOGRAPHIC CAMERAS to be as follows:-
My invention relates to photographic cameras, and the employment therein of
paralell bars, or bars for producing paralell motion, as a means of supporting parts,
and altering the relative positions of parts forming said camera, particularly in
reference to the means of supporting and connecting the front board and body of a
photographic camera, in various focal positions, either with or without the aid or use
of a base board: the bars connecting front board and camera body being actuated by
springs, or by mechanical power, or a combination of springs and pneumatic power.
In this invention, I connect the camera body and front board by means of a frame or
frames, said frame or frames being constructed of two or more paralell bars forming a
diagonal framing similar to the arms of an ordinary wool winder, or the framing of a
lattice girder without the side or end bars, and capable of extension or contraction,
the bars being connected together by means of rule joints or suitable rivets. In order
more clearly to describe this part of my invention, I have annexed hereunto a sheet
of drawings containing diagrams illustrating method of arranging paralell bars or
diagonal framing hereinafter described, but without reference to the shape or number
of bars forming said framing, which may vary according to the strength required or
distance to be extended. These diagrams I have marked with letters to which I
hereinafter refer. Figs. 1 and 2 show varied constructions of framing more or less
extended, and in Figs. 3 and 4 the same framing is represented contracted.
For transmitting motion to said paralell bars for the purpose of extending or con-
tracting the distance between the camera body and front board, I employ either rods
having right and left hand screw threads formed thereon, with screw nuts, to which
onds of diagonal bars are attached, and which are actuated by suitable gearing, or I
employ plain rods with sliding collars to which ends of paralell or diagonal bars are
attached, said sliding collars being actuated by catgut, wire, or other suitable material
passing over pulleys, or by springs.
In order to connect the camera body and front board, I attach a vertical bar to
each of two sides of either camera body or front board, but preferably the camera
body this vertical bar may be either tubular or solid: the ends 6 of diagonal framing a,
attach to collars or sliding pieces which fit on or in aforesaid tubes or bars, and
tension or compression is caused to be exerted on these collars or sliding pieces either
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by volute, coil, or other suitable springs, with wire, cord, catgut, or similar material
passing over pulleys and attached to said collars the end c of diagonal framing I
fix permanently in a central position on the aforesaid rod or tube, and from which
each of the ends b are equally distant; by these means when the ends 6 are moved
nearer to, or further from each other, any unequal pressure there may be exerted on.
ends 6, by springs, catgut, wire cord, or other motor, is neutralized and the diagonal
framing is retained at right angles to the camera body, whether said framing is
extended or contracted; to support the front board and connect it with camera body,
I attach permanently the end d of diagonal bars to each of the two vertical sides of
front board or frame thereof the ends e are free to move nearer to or further from
each other, but are retained in grooves, or are by other suitable means connected with
frame of front board by these means when the ends b of diagonal framing are
brought nearer together or placed further apart, the ends e will also come nearer
together or move further apart, but the points c and d being permanently fixed, the
paralell or other relative position of the camera body and front board is retained by
the bars, irrespective of the distance between the front board and camera body,
which may be increased. or lessened by the bars a being extended or contracted; if
springs are employed to act on the collars or sliding pieces connected to ends b of
diagonal framing, for the purpose of either extending or contracting said framing, and
thus opening or closing the camera, I attach rollers or pulleys to the camera body,
and over these rollers or pulleys, catgut, wire, or other suitable material may wind and
cause the ends b of framing to come nearer together or move further apart. The
roller on which the slack wire or catgut is wound I fit with a ratchet and pawl, by
which means the camera body and front board are retained at any distance apart:
when the ratchet is released, the front board is extended at any distance from the
camera body, or a reverse action may be obtained if the said springs are placed in a
contrary position.
When springs are not employed to act on said collars or sliding pieces, I use
endless bands of wire or other suitable material to actuate said collars or sliding pieces
in the direction required. The framing a may otherwise be extended or contracted
by means of each of the said vertical side rods herein before mentioned being formed
with a right hand screw thread at one end, and a left hand screw thread at the other
end, the collars or sliding pieces herein previously mentioned being also formed with
a corresponding screw thread to fit on these rods: I attach transverse rods fitted with
pinions or other gearing to rotate these vertical side rods simultaneously and thus
cause the ends b to approach nearer to or recede from each other as desired: this
transverse rod may be moved by hand or by spring power.
With the arrangement of diagonal bars supporting and connecting the front board
and camera body herein above described, the employment of a base board is not
necessary, but may be used in conjunction with said bars when preferred.
For the purpose of attaching the legs for supporting the camera when a base board
is not employed, I form an extension frame similar to frames herein before described
which I connect in a horizontal position to the underside of camera body: to this frame
either the tripod head, revolving rings, or other preferred form of attachment for
camera legs, is connected. When folding legs are employed I connect suitable framing
to camera body by means of arms or brackets formed so as to swivel on sides of
camera body to this framing the camera legs may be attached either permanently or
otherwise the frame I form so that it will fold against the camera body, when the
camera body is not in use, but when the camera is required for use, the said arms or
brackets are turned downwards, and the framing either with or without camera legs
attached will by these means be brought to the underside of camera body, the said
camera resting thereon.
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page_text: Improvements in Photographic Cameras.
I, THOMAS PRESCOTT of Arcade Chambers, St. Mary's Gate Manchester in the
County of Lancaster Mechanical 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 Camoras, and the employment therein of
parallel bars which are attached to permanent pivots or centres for the purpose of
producing parallel motion and also as a means of supporting parts and altering the
relative positions of parts forming said camera, particularly in reference to the means
of supporting and connecting the front board and body of a photographic camera, in
various focal positions, either with or without the aid or use of a base-board. In this
invention I connect the camera body and front board by means of a frame or frames,
said frame or frames being constructed of two or more parallel bars forming a diagonal
framing which is centrally attached to permanent pivots or centres thereby differing
from what are termed ordinary laztongs, said framing being similar to the arms of an
ordinary wool winder, or the framing of a lattice girder without the side or end bars,
and capable of extension or contraction, the bars being connected together by means
of rule joints or suitable rivets. In the arrangement of these bars in order to obtain
parallel motion, I attach permanent pivots or centres to the camera or parts of camera,
said pivots or centres being arranged so as to move or be moved to or from each other
in a straight line while the extreme ends of the parallel bars are free to move or be
moved either in grooves or on ferrules, said ferrules being formed so as to slide or
screw on rods in the same way as an ordinary wool winder. I employ similar means
to support the turntable when the ordinary form of base board is not used.
In order more clearly to describe this invention I have annexed hereunto, two sheets
of drawings. In the several views shown in these drawings, similar letters refer to
similar parts. Fig. 1. is side view of a photographic camera constructed according
to this invention. In this view the camera is represented as being closed. Fig. 2. is
side view of the same camera but is represented as having been opened. Fig. 3. is
part sectional elevation of body of camera on line drawn through grooves b¹. Fig. 4.
is plan of body of camera and turntable. In these views the permanent pivot or
centre c is attached in a central position to side a¹ of camera body and the permanent
pivot or centre d is attached in a corresponding position to each side of front board
or frame thereof the distance between the pivots d or c and the centres f₁ are
precisely the same as the distance between the centres fi aud c¹. I form the frame a
with any convenient number of centres c¹ placed in a line between d and c. The
extended ends 6 of the bars a are formed so as to slide in the grooves . By these
means when the permanent pivots or centres d and c are caused to approach nearer to,
or recede from each other, the positions of centres c, c and d are maintained in a
straight line.
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bar o.
The ends e of bars a slide in grooves a*. To prevent friction they may have rollers e¹
attached to them as shown in Fig. 2. When it is preferred to dispense with the ordinary
form of base board, I attach to either one or both sides of camera body a pivotted bar h.
The pivot or centre j is permanently attached to body a¹ of camera by means of the
dovetailed radial groove k. The upper end of bar h is retained in vertical groove m,
and the lower end is attached to pivot or centre which is secured to end of cross
The position of the permanent pivot or centre is precisely the same distance
from either of the points or . I form the semicircular groove k with a radius
extending from the point j. The position of point j¹ is determined by drawing a line
horizontally from the point and vertically from the point 1, the position of the
centre is the point where these two lines meet. A line drawn from the point to
the point would be of the same length as a line drawn from the point ; to the
point 1.
When the permanent pivot or centre j Fig. 1. is moved along the groove k
the end of bar travels downwards in groove m and the cross bar o is by these means
caused to move away from the body of the camera in a straight line while retaining
parallel position, and the same level as the underside of body of camera as shown in
Fig. 2. To the centre of the cross bar o I attach an angular ring n either by means
of an ordinary set screw o¹ or other suitable appliance. The flange n¹ of said
ring I form to fit into semicircular recesses p. p p attached to underside of camera
body a¹.
a
By these means the camera can be revolved on ring n to any position as represented
by dotted lines in Fig. 4. Either folding or ordinary legs may be employed on which
to support the ring n ordinary legs being attached to the lugs n²; Fig. 5. represents
a photographic camera constructed according to this invention and having a base board
to which any of the usual forms of tripod head or turntable may be attached. In this
view the front board a² is shown supported on extension framer in base board 7. I
form the frame a with permanent pivots or centres c and d as shown in Fig. 2. and
herein previously described. In order to close the camera, the front board a' is caused
to be moved back along the extension frame r until it reaches the projection on said
frame which then causes the extension framer to be also drawn back to level of base
board q and the front board a² is then close against or just within the camera body a¹
as shown in Fig. 1. The base board g which is hinged or otherwise suitably attached
to camera body a¹ is held in position when the camera is open by the bar herein
previously described. In this view the pivot ¹ is formed to slide in groove 1. When
the bar h is turned up in the position shown in Fig. 1. the base board q can then be
folded against the camera body.
In order to open the camera for use the base board q is turned down and fixed with
bar has shown in Fig. 5: the front board a² is caused to move along the extension
frame until it reaches the termination of the base board q, the bottom of the front
board a then comes in contact with the projection at end of extension frame when
said frame is by these means extended the distance required. Fig. 6. represents a
modification in which ends e of bars a are free to pass through grooves formed in
front board a3 which is secured in position by set pins e. Fig. 7. shows rods or tubes &
on which ferrules t either slide or screw and which are placed and retain an equal
distance on each side of the permanent pivot or centre c when moved to or from said
centre. In order to reduce or increase the distance between the perinanent pivots or
centres c and d I use either catgut, cord, wire or like material which is employed so as
to form endless bands. In the annexed drawings I have shown the catgut or liko
material passed over or round pulleys v, v², v², v* and connected to the free ends b of
bars thus forming endless bands and r¹. By means of the toothed wheels y that
are attached to rollers v³ and v³ and which gear into each other the endless bands
and are caused to move in reverse directions. By revolving either of the
rollers v, v¹, v² or the bars fare caused to open or close as required and by these
means the centres c and d are placed nearer to or further from each other as are also
the centres c¹ while retaining a parallel or lineable position. Fig. 8. is a detail to
enlarged scale of toothed wheels y the rollers and ³ and endless bands x and x¹.
The necessary amount of swing in body of camera may be obtained by means of the

page_text: y
rack to which the frame of back of camera is pivotted at z. The rack y is formed
to slide in groove and is actuated by the pinion y¹. When a base board is used to
support a photographic camera I employ bands of catgut, wire, or other like material
for the purpose of altering the position of the front board in lieu of the ordinary
racks and pinions by said catgut or other material being passed over rollers in the
manner similar to that herein previously described and I attach the rollers to base
board or extension frame or both. These rollers may either have coil springs attached
to them similar to those in use on ordinary spring tape measures, or they may be used
without springs. If springs are used the position is adjusted by means of ratchet
wheel and pawl.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I would have it clearly understood
that I do not claim in a photographic camera the application of what are termed
ordinary lazy tongs as they have been more or less used in photographic cameras prior
to the date of this my invention but I declare that what I claim is
1st. In a photographic camera the use of permanent pivots or centres such as are
marked c and d on drawings in combination with parallel bars that are supported by
and connected with bars marked f on drawings, which radiate from the herein before
mentioned permanent pivots or centres, in order to obtain either a forward or retro-
grade straight line or parallel movement of parts of camera without altering otherwise
the relative position of such parts to which said permanent pivots or centres are
attached substantially as herein before described.
2nd. In a photographic camera the means for obtaining a parallel or straight line
movement by combination of the pivot or centre j the bar h and the grooves k and m
substantially as herein before described.
3rd. For the purpose of revolving a photographic camera when set for use the
combination of ring n the semicircular recesses p, p' and p² and the bar o in connection
with bar h substantially as herein before described.
4th. In a photographic camera, and for the purpose of transmitting motion to parts
of said camera, the use of bands formed of catgut, wire or like material which are
employed either in the manner herein before described and illustrated or otherwise
similarly applied and form endless bands.
=
5th. The arrangement for obtaining swing in body of camera by means of permanent
pivot in combination with the rack y the pinion y and the groove 2¹ substantially as
herein before described.