Improvements in Automatic Sighting Apparatus for Ordnance.
Year: 1898

page_text: Date of Application, 1st Sept., 1898-Accepted, 21st Jan., 1899
COMPLETE SPECIFICATION.
Improvements in Automatic Sighting Apparatus for Ordnance.
I, LOTHIAN KERR Sco11, CB, late Lieutenant-Colonel of the Royal Engineers,
of Forest Lodge, Farnborough, in the County of Hants, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly descrubed and ascertained in and by the following statement.―
My invention relates to the automatic sighting of ordnance and refers to improve
ments in the automatic sighting apparatus described in the Specification of my
prior British Patent No 159 of 3rd January 1894, and also in the Specification of
my Application for British Patent No 7584 of 29th March 1898
In the Specification of Patent No 159 of 1894 the sight is so combined with the
gun that by a single operation of the elevating gear, (provided an initial adjust-
ment be correctly made), the adjustment of the sight for range 18 effected as the
line of sight is brought upon the object aimed at This is effected by gearing a
toothed segmental rack fixed to the gun mounting, with a traveller cared by a
tube or bar attached to the gun parallel to the longitudinal axis thereof, by means
of a train of pinions and pivoted segmental toothed racks; the said traveller, when
the gun is elevated or depressed, operating a range curve and telescope hinged
at one extremity to the said tube or bar
In the Specification of my British Application for Patent No 7584 58, various
modifications of the aforesaid apparatus are described and also an adjustable range
curve of special construction
The object of my present invention is first to lessen the chance of there being any
loss of time between the movement of the gun and that of the traveller owing to
back lash in the gearing between them, and secondly to furnish the automatic
sighting apparatus with a series of rapidly interchangeable ready made lange
curves each of different curvature; so that when it is required to change the curve,
Instead of altering the component parts thereof as set forth in the Specification of
my Application No 7584 of 1898, a new curve is substituted therefoi
I effect the first object of my invention either by using toothed gear wheels of
special construction or by replacing the said fixed toothed rack, pinion, and
toothed segment geaning as described in the Specification of Patent No 159
of 1894, by means which tiansnut the motion of the gun, when elevated or
depressed, more directly to the range curve traveller.
In the latter case I fix an aim vertically or otherwise to one of the trunnions of
the gun, or (if the gun is mounted in a sleeve) to one of the trunnions of the sleeve.
To the end of this arm I pivot a lever the longer arm of which is connected to a
traveller movable longitudinally on a horizontal bar and the shorter arm of which
15 pivoted at a fixed point on the gun mounting. The said horizontal bar 18 suit-
ably attached to the gun or to its truunion or to the fixed arm or other suitable part
of the gun mounting and is parallel to the longitudinal axis of the gun
A lange
curve is adapted to rest on the traveller and a telescope or sight bai is connected
to the range curve.
When the gun is elevated or depressed the extremity of the shorter arm of the
lever moves about the fixed point or fulcrum on the gun mounting, but the vertical

page_text: aim to which the lever is pivoted moves with the gun and causes the longer
of the lever to operate the traveller and thereby effect the necessary adjustment
of the sight for lange
To multiply the movement of the traveller in order to render the adjustment and
indications of the device less minute, the longer arm of the lever may be lengthened
as required
In order that my invention may be clearly understood and readily carried into
effect I will now proceed to describe the same more fully in connection with the
accompanying drawings in which:
Figure shows a side elevation of part of a gun and its mounting, having my
invention applied thereto.
Figure 2 is an enlarged side view of part of the traveller bar and the traveller,
of the arrangement shown in Figure 1, the traveller collar and bosses being removed.
Figure 3 is an enlarged side view of the said traveller with its collar and revolv-
ing boss.
Figure 4 is an end section on line of Figure 3
Figure 5 shows an alternative device to be employed instead of the revolving
bosses.
Figure 6 shows, partly in section, a toothed wheel for use when the range curve
traveller 18 operated by means of a fixed toothed rack and pinion gearing of the
kind described in the Specification of my aforesaid Patent (No 1599)
Figure 7 shows, on an enlarged scale, a series of interchangeable range curves
allanged radially round a central axis and
Figure 8 shows, on an enlarged scale, a series of interchangeable range curves
airanged as a set of revolving cams with which the object glass end of the tele-
Brope or sight bar engages
This
Referring to Figures 1 to 4, A is the gun of which a is a trunnion
trunnion is produced a short distance beyond its bearing and has a vertical arm a¹
fixed to such produced part so as to move therewith
b
To a pun a at the lower end of this aim a¹ 18 pivoted a lever the longer aim C
of which has its extremity forked and engages with the traveller D and the shorter
arm c of which also has its extremity forked on slotted and engages with a pin
fixed to the gun mounting B. E is a horizontal bar mounted parallel to the long-
tudinal axis of the gun and capable of moving about its axis in bearings a³, a³
fixed to the upper end of the vertical arm a¹ Or these bearings may be carried
by the gun or trunnion, or gun mounting On this bar E the traveller D can
slide longitudinally, and if the said bai is circular in cross section it is provided
with a longitudinal groove e with which a feather on the traveller engages in
order to prevent it rotating independently of the said bar. F is the range cuive
frame having its end at one extiemity hinged at e to the bar E and its end at
the other extremity mounted so as to slide vertically in the guide e also attached
to the bar E.
G 18 the telescope carried by the range curve fiame F and movable therewith.
18 a worm wheel fixed to the bar E, and a is a tangent worm or screw which
engages with the worm wheel and 18 furnished with a milled head and carried
in bearings in one of the brackets a³
k
The traveller D is provided with a roller d on which the range curve rests and
has an annular groove d¹ (Figure 2) formed therein with which engages an
accurately fitting collar H This colla H has projecting at either side thereof a
trunnion h the end of which is reduced and furnished with an annulai groove h¹.
K, K are bosses each of which has a spherical pait with a transverse passage
Each
formed therein, and a recessed part which fits onto one of the trunnions
of these bosses is free to 1otate on its trunnion hand 18 held in engagement there-
with by means of screws which pass through the wall of its recessed part and
project into the annular groove h of the trunnion Through the passages & the
When the gun 18
prongs of the forked end C of the lever pass respectively."
elevated or depressed the vertical arm a¹ will be moved and will carry the pivot a

page_text: with it, the forked extremity of the shorter arme of the lever will be retained in
engagement with the fulcium b fixed to the gun mounting and the forked end
of the longer arın C of the level will be caused to move in a circular path about
the fulcrum b and (by means of its prongs engaging respectively with the rotating
bosses as above described) will cause the traveller to move along the range curve
and give the telescope the necessary adjustment for range.
In the modification shown in Figure 5 the rotating bosses are dispensed with
and replaced by the perforated blocks M The trunnions h of the collar H are not
reduced but work in the blocks M which are mounted upon them. Each of the
prongs of the forked end of the arm C of the lever has a longitudinal recess or
fork at its extremity provided with a groove 3, in which one of the blocks M
mounted on its trunnion h, slides when the lever operates the traveller
The sight can be levelled to correct transverse regularities of platform by
means of turning the milled head of the worm or sciew a and thus moving the
bar E about its horizontal axis in the required direction together with the traveller,
range curve and telescope which are attached thereto, the collar H and bosses K, K
or blocks M, remaining stationary
Referring now to Figure 6, which shows a toothed wheel constructed so as to
take up back lash in order to obviate loss of time when using toothed gearing,
ths wheel 18 formed in two halves A and B carried by a rotary pivot P Each of
these halves has similar teeth o çogs formed on its periphery The part A 18
fixed to the pivot P by means of a cotta o pin a or other suitable means, and
the part B is mounted so as to be capable of rotary motion on the pivot P $ 18
a coiled spring one end of which is fixed to the pivot P and the other end of which
bears on a stud b carried by the part B. p is a washer fixed to the pivot P for
retaining the part B in position
When this gear wheel is in use the spring S tends to cause the parts A and B
thereof to rotate in opposite directions
The required pressure of this spring when arranged as aforesaid, is obtained by
simply tuining the part B of the wheel 1ound the pivot P untal the two halves of
the wheel are pressing in opposite directions with a sufficient pressure; then by
forcing the teeth of two halves of the wheel together into gear with the teeth of
an ordinary toothed wheel or segment, the two wheels, or the wheel and segment,
will always gear closely together, and there will be no loss of time between them
when laying the gun, provided the pressure to be overcome in order to operate
the sight is not greater than the pressure exerted by the spring S.
It is obvious that a toothed segmental lack may be constructed in a similar
manner to the aforesaid toothed wheel without departing from the spirit of my
invention.
I may make use of an adjustable range curve of the type referred to in the
Specification of my Application for British Letters Patent No 7584 or I may
employ a set of interchangeable range curves hereinafter described with reference
to Figures 7 and 8.
Refering to Figure 7, which shows a series of ready made interchangeable
range curves, each of different curvature, arranged radially round a central axis,
E is a screw rod on which the traveller D moves and is prevented from rotating
by means of the guides q g as described in the specification of my aforesaid previous
application a'a are the brackets suppoiting the bai E and guides gg. "Hinged
o these guides at et is one end of a 1od or bar E¹ the other end of which carnes
vernier e which is read in connection with a scale marked on the guide canned
by one of the brackets a³
Carried in suitable brackets gig fixed to this bar E
6 the telescope and sight bar G Fitting the 10d E¹, between the brackets g' g¹
and so as to be capable of revolving thereon, is a sleeve F to which are fixed so
sto radiate therefom a series of range cui ves each of different curvature
ither end of this sleeve F¹ 18 arranged an annular series of perforations f one of
which coincides with each of the radiating curves F. Subjacent to each of these
eries of perforations is a depression or recess in the rod E.
At

page_text: or
In order to noimally prevent the sleeve F¹ moving about the bar E', a pin p
passes through one of the perforations f of each series into the said recess
depression in the bar E. One of the curves F rests upon the roller of the
traveller D, and when it is required to change the cuive the pins are withdrawn,
and the sleeve Frotated about the bar E until the required curve rests upon the
traveller roller and the pins then readjusted. A tangent screw at and worm
wheel are provided, as previously described, for cross levelling the sight
Figure 8 shows a series of lange curves F each of different curvature arranged
transversely to the telescope G and keyed or otherwise fixed to a sleeve Fl fitting
the bar E so as to be capable of revolving thei eom; the bai E is mounted in the
brackets as a³ Fixed to this bar E is the bracket Q to which 19 hinged at el a
bracket Q in which one end of a 10d E³ carrying the telescope, slides
In this
rcd E are a series of depressions the spaces between which are each equal to
the width of a cam F, and in the top of the bracket Q' is a perforation f. Attached
to the top of the bracket Q¹ is one end of a spring S the fice end of which caries
a pin p, which normally passes through the perforation into one of the depies-
810ns and prevents the bar FS from sliding. Depending from this sliding bau E
1s a projecting piece G₁ which rests by gravity upon the required range curve
When it is required to alter the range curve the pin is lifted out of the depies-
81on in which it is resting and the piece G¹ placed upon the required one of the
cams F, the bar E sliding to permit this; the pin p is now released and springs
into a fresh depression and thus firmly retains the bar in position.
Upon the sleeve F¹ 18 keyed or otherwise fixed a pinion which 18 geared with
the automatic sight elevating screw as set forth in the Specification of my Applica-
tion No 7584% above referred to
In order to enable the telescope, the bar E and sleeve F¹ to be cross levelled
together without altering the angle made by the axis of the gun with the axis of
the telescope, I may pivotally attach the brackets a³ to the gun mounting or
carriage and provide one of them with a thumb screw revolvably attached to the
gun carriage
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 In sighting apparatus of the type referred to, a range curve traveller com-
prising a part that tiarels on and is capable of angular movement with the
traveller bar and a part that is capable of independent vertical angular movement
around the first mentioned part, for the purpose specified
2. In sighting apparatus of the type referred to, the operation of the traveller
through the medium of a lever pivoted to the gun mounting substantially as
described.
3. In gear for operating sighting apparatus of the type referred to, a toothed
wheel or segment comprising two parts which tend to rotate about a common axis
in opposite directions, for the purpose specified.
4 In sighting apparatus of the type referred to, a series of interchangeable
lange curves each of different cui vature and capable of being readily brought into
operative position substantially as and for the purpose specified
5. Sighting apparatus of the type referred to, constructed, arranged, and
operating substantially as herein described with reference to Figures 1 to 5 or to
Figures or to Figures 7 or Figure 8 of the accompanying drawings, for the
pui pose specified
Dated this 25th day of August 1898.
HASELTINE, LAKE & Co,
45, Southampton Buildings, London, W.C., Agents for the Applicant.