Improvements in or relating to Telescopic Sights for Ordnance.
Year: 1895

page_text: Date of Application, 10th Jan., 1895
Complete Specification Left, 9th Nov., 1895-Accepted, 10th Jan., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Telescopic Sights for Ordnance.
I, LOTHIAN KERR SCOTT, of Forest Lodge, Farnborough in the County of
Hampshire, Lieutenant Colonel Royal Engineers, do hereby declare the nature of
this invention to be as follows:-
This invention relates to improvements in or relating to telescopic sights for
ordnance said improvements being more particularly applicable to telescopic sights
of the kind referred to in the Specification of a former Patent No. 5053 granted to
me on the 18th day of November 1881.
The first part of my invention consists in applying to my telescopic sight a drum
or cylinder having a spiral thread or band formed on its exterior surface and
provided with an indicator nut or collar which is adapted either to revolve upon
said drum or to remain stationary thereon. The drum is furnished with suitable
graduations in proximity to the spiral thread and the indicator nut or collar is
provided with an index or pointer which can be brought in contiguity to any.
desired graduation on the drum.
Another part of my invention consists in the application of a spiral drum and
indicator collar similar to that above referred to, to any level that is adapted to be
used as a clinometer.
Another part of my invention consists in the application of the spiral drum and
indicator collar to the telescope tube whereby the rack and pinion arrangement
inside the telescope which has hitherto been used for focussing my telescopic sight
can be dispensed with.
Another part of my invention consists in applying to my telescopic sight an
adjustable vernier scale to the fixed vernier piece on the telescope; and likewise
consists in applying an adjustable vernier piece to the before mentioned indicator
nut or collar working on the spiral drum, said vernier piece having a movable
index or zero pointer thereon.
Another part of my invention consists in so constructing the longitudinal level
of my telescopic sight that it is capable of shifting in a vertical plane independently
of the movement given to it by turning the worm or screw spindle of the
telescope.
Another part of my invention consists in applying to the vertical arc of my
telescopic sight a worm or screw spindle having at one end a ball and socket
joint enclosed in a screw cap or the like and near the other end a spring controlled rod
or piston which is so situated as to exert an equal lateral pressure upon the said worm
spindle in whatever position the telescope may occupy on the vertical arc, whereby
the worm with which the spindle is provided is always kept in gear with the teeth
of the rack segment carried by the telescope and "backlash" or "loss of time"
between the said worm and rack is thus prevented.
The above mentioned so called ball and socket joint consists of a curved or
spherical portion formed on the lower extremity of the said worm spindle such
curved or spherical portion being approximately a quarter of a sphere with radial
surfaces meeting at a point constituting the centre of the said sphere and
situated immediately below this central point is a plate or disc which is kept
pressed against said central point by means of a spiral spring contained within the

page_text: lower part of the surrounding case or cup enclosing the quarter sphere. In this
manner the central point is effectually prevented from shifting out of its vertical
position.
Another part of my invention relates to the manner of clamping or connecting
the spiral drum or the micrometer collar to the milled head of the worm spindle.
Another part of my invention relates to a modified arrangement of that just
referred to whereby the spiral drum can be more conveniently locked to the screw
spindle.
Another part of my invention consists in providing a graduated circular back
sight for carrying the telescope, the curvature of said circular back sight being
equal to a circular arc struck from the tip of the foresight. In this way the axis
of the telescope will always be in a line with the tip of the foresight irrespective
of the position of the telescope on the back sight. I may make the back sight
with a hinged or pivotal connection and provide a spring for keeping the back
sight in its vertical position so that when the gun is fired the shock of discharge
will cause the backsight to slightly tip forward about its pivot and thus avoid
detrimental shocks to the telescope.
By providing my telescopic sight with the before mentioned graduated spiral
drum I am enabled to multiply the present short length of the arc of vertical
movement of the telescope for a given number of degrees to such an extent that
more minute measurements such as single yards of range or even minutes of
elevation (which are at present only readable with difficulty by the aid of a
vernier and magnifying glass) may be represented in larger and more readable
graduated divisions and figures with which the spiral druin is provided. I can
thus if required dispense altogether with the present system of reading minutes with
a vernier.
I may apply the said graduated spiral drum and its indicator nut or collar to my
telescopic sight as follows:
The before mentioned screw or worm spindle may be prolonged and the spiral
drum be located thereon below the milled head to which it may be clamped or
connected in the same position as that at present occupied by the micrometer
collar. The drum may be clamped or connected to the milled head by the means
employed for clamping the micrometer collar to the milled head, which means
constitute an essential feature of my present invention. These means consist in
providing the drum (or the micrometer collar) with an enlarged conical head over
which fits a ring that is adapted to enter an undercut portion or groove formed in the
lower surface of the milled head. Screws are passed through the said milled head
and enter tapped holes in the said ring so that when the screws are tightened
up the ring is caused to firmly press the conical head of the drum (or of the micro-
meter collar) into the groove of the milled head and thereby rigidly connect the
parts together. The drum (or the micrometer collar) can be turned axially and
be adjusted into any desired position by loosening the said screws. Instead
however of adjusting the drum in this manner I may screw-thread that portion of
the spindle which is in proximity to the lower end of the drum and arrange a nut
to work thereon so that by screwing up or unscrewing said nut the drum can be
locked to the spindle or be rendered free to turn thereon. It will be seen that
by connecting said drum to the milled head as above explained the screw spindle
and the drum revolve together when the milled head is turned but the drum itself
does not impart movement to the telescope, such movement being effected by the
worm on the spindle engaging with the segmental rack. In this arrangement
the indicator nut or collar does not revolve but is caused, by suitable means, to
move in a direction parallel to the axis of the drum, and the extent of this
movement is controlled by the pitch of the spiral on the drum, which pitch is
entirely independent of the pitch of the worm that imparts motion to the telescope.
This is of considerable importance as the spiral band can be of any required
width to enable clear graduation and figuring thereof, and said drum can be made
of any convenient length and diameter to suit the construction of my ordinary

page_text: telescopic sight in the event of its becoming necessary to convert it into one provided
with the present improvements.
Instead of applying the graduated spiral drum and its indicator nut or collar to
my telescopic sight as above described I may locate it upon the said screw
spindle at a point below the worm thereon and in this case the diameter of
such worm would be increased so that it would project beyond the circumference of
the spiral drum. In this case also the spiral drum would be clamped or connected
to a disc or collar situated near the lower end of the worm spindle and in an
analogous manner to that already mentioned with respect to the milled head.
In accordance with another method of applying the spiral drum and its
indicator nut or collar to my telescopic sight I may lecate the spiral drum on the
tube of the telescope and so arrange the indicator nut or collar that it will travel
smoothly along said telescope tube and by its movement alter the inclination of
the telescope. For this purpose I may pivot the telescope between a pair of fixed
side plates or cheeks each of which may be formed with a curved or inclined slot.
Projections or trunnions carried by the indicator nut or collar enter these slots
and as said trunnions travel along the slots the telescope is caused to turn about
its pivot and its inclination is thus altered. A spring may be provided for tending
to keep the telescope tube in its horizontal position. The curved or inclined slots
if desired be dispensed with and a separate inclined or curved piece connected
to the frame of the telescopic sight be employed instead.
may
The spiral band of the drum may be made wide enough to enable two distinct
sets of parallel scales or graduations to be employed one of said scales being
graduated say in yards and the other in minutes and degrees. I can thus dispense
with the graduated arc and vernier employed in my ordinary telescopic sight. An
index piece or traveller is fitted on the indicator nut or collar both of which parts
are provided with zero points and said index piece is so arranged as to be capable
of shifting to one or other side of the fixed zero point on the indicator nut or
collar. By these means the guns of a battery requiring different elevations may
for convenience in "ranging drill" have all their elevations assimilated on the
elevation scale without actually altering the elevations of the guns. This also
applies to the use of the shifting vernier.
The spiral drum and indicator nut or collar can be applied for gunnery purposes
to any spirit or similar level for imparting angles of elevation thereto in an
analogous manner to that already stated with respect to the telescope. In order
to ensure that the level shall give true angles of elevation to the axis of the
gun under all conditions and when the said level is situated on the plane of the
gun, and the levelling is performed by turning the elevating screw of the gun,
I affix the said level to a tray which is carried in bearings formed in arms or
brackets projecting from the base plate or frame of the level. The level is thus
capable of revolution about an axis which is coincident with or parallel to the longer
axis of the level.
Improvements in or relating to Telescopic Sights for Orunance.
I, LOTHIAN KERR SCOTT, of Forest Lodge, Farnborough, in the County of
Hampshire, Lieutenant Colonel Royal Engineers, 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 :-
This invention has reference to improvements in or relating to telescopic sights

page_text: for ordnance, said improvements being more particularly applicable to telescopic
sights of the kind referred to in the Specification of a former Patent No. 5053
granted to me on the 18th day of November 1881.
An essential feature of my present invention consists in applying to my before
mentioned telescopic sight a drum or cylinder having a spiral groove, thread or
band formed on its exterior surface and provided with an indicator nut or collar
which may be adapted to be revolved upon the said drum to shift the latter
longitudinally, or the drum may be arranged to revolve and thereby shift the nut
or collar longitudinally. The said drum is furnished with suitable graduated
divisions and figures representing say yards and the indicator nut or collar is
provided with an index or pointer which can be brought into contiguity to any
desired graduated division on the drum by revolving the latter; or, if the drum
be incapable of revolution, by revolving said indicator nut or collar. By these
means I am enabled to multiply the short length of the vertical angular movement
of the telescope for a given number of degrees to such an extent that more minute
measurements, such as single yards of range or even minutes of elevation (which
are at present only readable with difficulty by the aid of a vernier and magnifying
glass) can be represented by the larger and more readable graduated divisions
and figures on the spiral drum. The inconvenient system of reading minutes with
a vernier can thus if desired be altogether dispensed with.
The above mentioned spiral drum and indicator collar may be applied to the
worm spindle employed for giving the angular movement to the telescope, or may
be applied to the telescope itself as will be hereinafter fully explained. The spiral
drum and indicator collar can also be applied in an analogous manner to that
herein described to any level that is intended to be used as a clinometer for gunnery
purposes.
Another feature of my invention consists in the application of a screw focussing
collar to the outer or inner telescope tube, or to both tubes, whereby the rack and
pinion arrangement with which the telescope has hitherto been provided for
focussing my telescopic-sight can be dispensed with.
Another feature of my invention consists in providing the above mentioned worm
spindle with a so-called ball and socket joint or pivotal connection of special
construction, and also in providing said worm spindle with a spring controlled
device acting in conjunction with the ball and socket joint or pivotal connection.
By these means the teeth of the worm are kept in gear with the teeth of the
segmental rack carried by the telescope in such a manner that "back lash or
"loss of time" between said worm and rack, when the worm spindle is revolved, is
prevented.
"
Another feature of my invention relates to the manner of clamping or connecting
the spiral drum to the worm spindle in such a manner that it can be readily
adjusted circumferentially thereon and independently of the worm spindle when
desired, for the purpose of setting one or other of its graduations in contiguity to
the pointer or index on the indicator nut or collar.
Another feature of my invention consists in providing means for enabling the
elevation scales of a battery of guns to be assimilated without actually altering the
elevations of the respective guns, the said means consisting of an adjustable
vernier scale applied to the vernier piece carried by the telescope of my ordinary
telescopic sight; or of an adjustable vernier piece or scale applied to the aforesaid
indicator nut or collar.
Another feature of my invention consists in so constructing the longitudinal
level of my telescopic sight that it is capable of being shifted in a vertical plane
parallel to the vertical plane passing through the axis of the telescope tube and
independently of the angular movement given to it when the telescope is elevated or
depressed. When this level is so constructed it can be used for assimilating the
guns as above mentioned without the use of an adjustable vernier piece.
Another feature of my invention consists in providing a graduated curved
back-sight for carrying the telescope, the curvature of said back-sight being

page_text: equal to that of a circular are struck from the tip of the fore-sight, so
that the axis of the telescope will always be in line with the tip of the
fore sight whatever be the position occupied by the telescope on the back-sight..
The said back-sight is also hinged or pivoted at its lower part and is provided
with a spring which normally retains said back-sight in an upright position but
permits it to slightly turn forward about its hinge when the gun is discharged
and thus counteracts detrimental shocks that would otherwise be transmitted to
the telescope.
In order that my said invention may be clearly understood and readily carried
into effect I will describe the same more fully with reference to the accompanying
drawings in which :-
Figures 1 to 10 illustrate one form of telescopic sight constructed in accordance
with my present invention; Figure 1 being a side elevation, Figure 2 a plan, and
Figure 3 a vertical transverse section taken on the line 1. 1. of Figure 1.
Figure 4 is an elevation of the vertical arc detached from the sight and shewing
the side opposite to that seen in Figure 1.
Figure 5 is a vertical section of the spiral drum and Figure 6 is a plan view of
the lower end thereof.
Figures 7 and 8 are respectively a plan and a central vertical section of the
indicator nut or collar.
Figure 9 is a vertical section of the longitudinal level taken on the line 2. 2.
of Figure 2 and Figure 10 is an end view of this level as seen from the left..
The telescope tube is shewn in cross-section in this figure.
Figures 11 to 17 illustrate a modified construction of my improved telescopic
sight, Figure 11 being a side elevation, Figure 12 a plan and Figure 13 a vertical
transverse section taken on the line 3. 3. of Figure 11.
Figure 14 is an elevation of the vertical arc detached from the sight and shewing
the side opposite to that seen in Figure 11. In this figure the spiral drum carried
by the arc is also shewn in section.
Figure 15 is a plan of the vertical arc.
Figure 16 is a central vertical section of the longitudinal level employed with
this sight and Figure 17 is an end view thereof as seen from the left.
Figures 18 to 21 illustrate a further modified construction of my improved
telescopic sight; Figure 18 being a side elevation; Figure 19 a plan partly in
section; Figure 20 a vertical transverse section taken on the line 4. 4 of Figure 18;.
and Figure 21 a side elevation of the longitudinal level employed with this
sight. The last mentioned view is taken from the side of the sight opposite to that
shewn in Figure 18.
Figure 22 is a fragmentary sectional view of a spiral drum similar to that shewn
in Figures 4 or 14 and illustrating a modified manner of connecting the drum to
the worm spindle.
Figure 23 is a vertical section illustrating another arrangement of the spiral
drum on the worm spindle.
Figures 24 and 25 are detail views shewing the application of an adjustable
vernier scale to the vernier piece of the telescope tube of a sight similar to
that shewn in Figures 1 or 11; Figure 24 being an edge view and Figure 25.
a transverse section on the line 5. 5 of Figure 24.
Figures 26 to 28 illustrate the manner in which I construct the curved pivoted
back sight for carrying the telescope; Figure 26 being a side elevation, Figure 27 a
front elevation and Figure 28 a horizontal cross-section on the line 6. 6 of Figure 26.
Like letters of reference indicate similar parts in all the figures.
A is the telescope of the sight which is pivotted at B to the fixed vertical
are B. C is the worm spindle which is provided with a milled head C¹ for revolving
it and with the worm C' for imparting movement to the telescope through the
intervention of a rack segment A¹. D is the longitudinal level which according
to the present invention is capable of movement in a vertical plane as hereinafter
more fully explained. E is the bracket or frame to which the vertical arc is rigidly

page_text: Connected and
piece of ordnance.
are the pivots by waren sam bracket of frame is aimed to the
Referring more particularly to Figures 1 to 10 a is the drum or cylinder which
is formed on its exterior surface with a spiral groove or thread that runs
continuously from end to end thereof. The metal existing between the convolutions
of the spiral groove or thread constitutes a spiral band a whereon are located the
graduations and figures for indicating the vertical angular movement of the
telescope and which have hitherto been situated on the curved edge of the vertical
are B. a is the indicator nut or collar having a pointer or arrow a³ thereon and
the said nut or collar is capable of longitudinal movement upon the drum when the
latter is revolved, but is itself prevented from revolving by means of horus at
(Figure 7) which slide against the vertical guiding edges of an opening B' through
which the graduations on the spiral drum are observed. The worm C³ is fixed to
the spindle C by a pin C³ and is located above the aforesaid spiral drum a. The
diameter of the worm C2 is greater than that of the spiral drum so that the threa
of the worm can engage with the curved rack A' on the telescope. The lower
surface of the said worm C2 is formed with a shoulder C (Figure 5) and is provided
with a sleeve C whose lower end terminates in a disc C. The spiral drum a is
hollow and when in position on the spindle C its upper edge comes against the
aforesaid shoulder C of the worm C. The lower edge of the spiral drum is
formed with a circular recess C' which is adapted to receive a disc C (Figure 6)
this latter being provided with screw holes C through which screws C10 are passed
for securing the disc C8 to the dise C of the worm. It will be seen that when
this disc C is tightened up by its screws it presses the drum against the worm C
and thereby rigidly clamps it to the said worin so that when the spindle C is
revolved the drum revolves with it. When however these screws are loosened the
drum a is rendered free and can be turned independently of the spindle C and be
adjusted circumferentially so as to bring any particular graduation thereon opposite
the pointer a³. It is to be observed that the drum itself does not impart movement
to the telescope, such movement being effected by the worm C2 engaging with the
aforesaid rack A', consequently the pitch of the spiral groove or thread on the
drum is entirely independent of the pitch of the worm. This is an important
feature as it enables the distance between the spiral threads-that is to say the
width of the band a-to be such that the graduations and figures indicated
thereon can be made large enough to be clearly readable without the use of a
magnifying glass.
On the inner surface of the arc B is a curved guide B³ which is grooved to
engage with the rear portion of the rack A' so as to ensure steadiness in the
movements of the telescope tube when the milled head C¹ is actuated.
In order to ensure that the longitudinal level of the telescopic sight shall give
true angles of elevation relatively to the axis of the gun, I connect said longi-
tudinal level to the telescope in such a manner that it can be independently
elevated or depressed in a vertical plane coincident with or parallel to that of the
telescope.
In the telescopic sight illustrated in the preceding figures this is effected by
enclosing the level proper in a tubular casing d (see Figures 9 and 10) having
openings at its upper and lower sides and provided at one end with an arm di
which is furnished with a segmental rack d2 and an extension d³. The aforesaid
tubular casing d is pivotally connected by a screw d³ to a plate d' which, together
with the level, is adapted to slide longitudinally into a casing do, the latter being
formed with dovetail grooves for the dovetail longitudinal edges of the said
plate d to slide in. The before mentioned plate d has end pieces d' d8 which
when the plate is slidden into place in the casing d serve to close the ends thereof.
The end piece d' is however reduced somewhat in width so as to leave a space or
vertical slot within which the aforesaid extension d³ can move. The end of
this extension is visible through the slot de so that its position relatively to
graduations on the end piece d' can be observed. The angular movements of the

page_text: level are effected by means of a vertically arranged worm spindle d gearing
with the aforesaid segmental rack d² and adapted to be revolved by a head d
This head is preferably left plain, that is to say without any milling and is
provided with graduations. dx is a hinged mirror for reflecting the image of the
bubble in the level towards the breech of the gun.
In Figures 1 and 2 I have shewn the end of the outer telescope tube A screw
threaded at A* for the reception of a rotary collar F which is screw threaded on
its interior at F to engage with the screw threads A*. One end of this rotary
collar is provided with a milled portion F2 for enabling it to be conveniently
turned by the fingers and the other end connected to a ring or band J' which is
free to turn in a groove formed for it at J2 on the inner telescope tube J, carrying
the object glass. By revolving the rotary collar in one or other direction the
inner tube J is caused to carry its object glass towards or away from the end of
the outer tube A. The focussing can thus be effected without the use of a rack
and pinion as heretofore.
Figures 11 to 17 illustrate a modified construction of my telescopic sight in
which means are provided for avoiding "backlash" or "loss of time" between
the worm and the rack A'. For this purpose the lower end of the spindle C
instead of merely revolving in a socket B carried by the vertical arc B is formed
with a semi-spheroidal enlargement c' (Figure 14) having on its lower flattened
surface a central projection or boss c² which is located in line with the vertical axis
of the spindle C and bears upon a plate c³. This plate is situated immediately
beneath the boss c² and is pressed upwardly by a comparatively strong spiral
spring contained in a cavity formed in the socket B* projecting from the are B.
This socket is screw threaded to receive a screw cap B5 which serves to retain the
spiral spring and movable plate in place. The upper end of the spindle. passes
through a collar which is fitted to move laterally in a horizontal slot B6 formed
in the upper part of the arc B, and the said collar carries a rod or piston e* whose
uter end enters a cylindrical case or cap B7 containing a spiral spring. It will
therefore be seen that the worm (2 on the spindle C is kept in engagement
with the teeth of the rack A¹ by means of the lateral pressure exerted by the
aforesaid spring within the cap B and the vertical pressure exerted by the lower
spring c.
The longitudinal level employed in this construction of telescopic sight is
pivotally mounted in a cylindrical casing d¹² (Figures 16 and 17) which can be
inserted into the casing d through an end opening, this opening being afterwards'
closed by a screw d³. The opposite end of this casing d is provided with a
toothed disc d the teeth of which gear with a pinion d carried at the lower end
of the worm spindle do which latter as in the previous construction is employed
for shifting the level about its pivots in a vertical plane. The divisions or gradua-
tions for indicating the angular movements of the level are marked on the face of
the aforesaid toothed disc d. On reference to Figures 11, 12 and 13 it will be
seen that I have shewn this telescopic sight provided with the ordinary rack and
pinion arrangement for focussing the sight, the said focussing being effected in the
usual manner by revolving a milled head F*. But I wish it to be understood
that I may employ the focussing collar F with this construction of sight in an
analogous manner to that already described.
Figures 18 to 21 shew another construction of the telescopic sight in which the
spiral drum is applied to the tube of the telescope A. In this case the indicator
nut or collar a² is furnished with lateral studs or projectious a carrying rectangular
pieces a which enter curved or inclined slots G formed in side cheeks G carried
by the frame of the sight. The telescope A is pivotted at G2 to the before
mentioned side cheeks and the spiral druin is provided with a milled head at A² to
permit of its being readily turned by the fingers. The act of turning said spiral
drum causes the nut a² to advance towards or to recede from the eyepiece of the
telescope and thereby elevate or lower this end about the pivot G owing to the
rectangular pieces a following the inclination or curvature of the slots. G.

page_text: H is a blade spring which tends to keep the eyepiece end of the telescope always
pressed in a downward direction. The drum is shewn provided with a double
spiral groove or thread so that two distinct bands a', a* are obtained, one of them
carrying graduations indicating, say, yards and the other graduations indicating,
say, minutes and degrees. The indicator collar is furnished with a movable or
adjustable piece a carrying on each of its sides a zero point represented by an
arrow head. This piece a' and its arrow heads can be slidden in either direction
along a groove as formed in said collar and can be locked by means of the set-
screw a in the required position. In this way the arrow heads on the said piece a
can be brought into correspondence with the graduations of either of the spiral
bands at pleasure.
The longitudinal level D employed in this construction of sight and best seen at
Figure 21 is pivoted at its extremity D¹ to one of the trunnions of the telescope
in such a way as to move either with the telescope or independently thereof.
This level is operated by means of the worm spindle do the worm of which
engages with rack teeth formed on the extremity D2 of the level. The move-
ments of the level are effected by operating the head d" in a similar manner to
that described with reference to the other constructions of levels hereinbefore
.described.
In the fragmentary section Figure 22 I have shown another manner of clamping
the spiral drum a to the worm spindle C. In this arrangement the spindle C is
formed with a screw threaded portion C" with which engages a nut C. By
merely turning this nut in one or other direction the said spiral drum can either
be tightly clamped between the said nut and the worm C' which is carried by the
upper portion of the spindle C and thereby be locked to the spindle, or be rendered
loose and capable of being turned on the worm spindle for the purpose of
adjustment as in the previously described constructions.
In Figure 23 I have shewn a modified arrangement of the spiral drum a which
is in this case located at the upper end of the spindle C instead of below the
worm C the said spindle being prolonged to receive the drum. The worm C² is
in this arrangement of reduced diameter. The upper end of the spiral drum is
provided with an enlarged or conical head a around which a ring a" is fitted and
the lower surface of the milled head C¹ is formed with an undercut portion or
circular recess c°. Screws c' pass through holes in the milled head and enter
tapped holes in the ring a¹¹. When these screws are turned in one direction they
cause the ring a" to approach the milled head C₁ and thus press the conical head
of the spiral drum tightly against the said milled head, thereby firmly locking these
parts together. By turning these screws in the opposite direction the said drum
is loosened and can be adjusted on the worm spindle C as in the foregoing
constructions. c is a screw for retaining the milled head C¹ to the spindle C.
Figures 24 and 25 shew the manner in which I construct the vernier piece A³
carried by the telescope tube, so that a battery of guns requiring different
elevations may for convenience in "ranging drill" have all their elevations
assimilated on the elevation scales without actually altering the elevations of the
guns. For this purpose I make the vernier piece A³ with a dovetail groove A¹
into which fits a corresponding portion A that constitutes part of the vernier
scale A. This scale can be readily shifted to or fro within the groove A* and
thus enables the zero point thereon to be brought into correspondence with any
desired graduation of the scale on the vertical are B without altering the vertical
inclination of the telescope. Thus notwithstanding the fact that the guns may all
be at different elevations one order from the officer in command to alter the
elevation of the guns to any particular angle, will suffice to enable all the guns to
be elevated or depressed to the same relative extent.
If desired, instead of employing the above device I may employ the before
mentioned longitudinal levels for assimilating the elevations of the guns in
ranging drill," the graduations with which the levels are provided serving for
this purpose.
66

page_text: Referring now to Figures 26 to 28 which illustrate the construction of the back
sight, ffare a pair of curved bars connected together at their upper ends by the
cross piece f¹ and at their lower ends by the plate f2 to which latter they are
pivotally connected at f³. f is a pintle extending from the plate f and by means
of which the sight is affixed to the gun in a stationary or a revolving bush..
ff are springs which are so arranged as to normally keep the curved bars in
their upright position, but which, when the discharge of the gun takes place,
permit said curved bars to tip forward slightly so as to more or less intercept the
shock which would otherwise be transmitted to the telescope. The curved bars-
are advantageously made of channel or H section and the telescope is provided
with sliders II projecting from a front plate having openings I therein for
permitting the graduations on the bars to be seen. The sliders are adapted to
slide up and down the said curved bars and to be clamped in any desired position
thereon by set screws 12 12. The curvature of the said curved bars as already
stated corresponds with that of a circular are described from the tip of the
foresight and in this manner the axis of the telescope A will always be in align-
ment with the tip of the foresight irrespective of the position occupied by the
said telescope on the curved bars.
The telescopic sights herein before described are used in the ordinary and well.
known manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A telescopic sight in which a spiral cylinder or drum and an indicator nut or
collar are employed for indicating the extent of the vertical angular movements of
the telescope substantially as described and for the purpose specified.
2. The methods of connecting or clamping the spiral drum to its spindle
whereby said drum can be circumferentially set or adjusted with respect to the
index or pointer on the indicator nut or collar independently of the said spindle
substantially as described and for the purpose specified.
"
3. The method of enabling " backlash or "loss of time" to be avoided
between the worm spindle and its toothed segmental rack substantially as
described.
4. A telescopic sight in which means are provided for assimilating the eleva-
tion scales of a battery of guns without altering the respective angles of elevation
of the guns substantially as described and for the purpose specified.
5. The construction of the longitudinal levels whereby they can be adjusted in
a vertical plane independently of the telescope substantially as described and for
the purpose specified.
6. The means for focusing the telescope without the use of the ordinary rack
and pinion, substantially as described with reference to Figures 1 and 2 of the
accompanying drawings.
7. The construction of the graduated back-sight substantially as described with
reference to Figures 26 to 28 and for the purpose specified.
8. A telescopic sight for ordnance, substantially as herein before described with
reference to one or other of the constructions illustrated in the accompanying.
drawings.
Dated this 8th day of November 1895.
Dated this 8th day of November 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.