Improvements in Training Gear of Central Pivot Gun Mountings.
Year: 1885

page_text: Improvements in Training Gear of Central Pivot Gun
Mountings.
I JOSIAH VAVASSEUR of the London Ordnance Works Southwark in the
County of Surrey Engineer do hereby declare the nature of my invention for
IMPROVEMENTS IN TRAINING GEAR OF CENTRAL PIVOT GUN MOUNTINGS" to be
as follows:
"
The improvements relate to the training gear of centrally pivotted gun mountings
of that class in which the training is effected by means of a horizontal toothed
wheel attached to the slide of the mounting and consequently moving therewith in
training the wheel being driven by means of a pinion gearing into it the bearing
of the pinion being stationary. If the toothed wheel is as heretofore rigidly
attached to the slide it is difficult when the pinion is driven by means of hydraulic
or other power so that the training is done quickly, to lay the gun on a given
object with sufficient accuracy. I remedy this in the following way. Instead of
attaching the horizontal wheel rigidly to the slide I make it as a ring supported in
guides on the slide, and capable of turning around the same but independently
thereof. I make on the ring one set of teeth forming a spurwheel suitable for the
driving pinion the same as for the arrangement above described and on the same
ring a separate set of teeth forming a worm wheel into which gears a worm of
which the bearings are fixed to the slide of the mounting the worm being driven
by suitable gearing preferably by hand from the battery.
On the pinion being driven-pressure will be communicated to the spur teeth
and be transmitted by the ring to the worm teeth and consequently to the worm-
and the latter being of sufficiently fine pitch or held by a brake so as not to
turn with the pressure motion will be communicated by a thrust on the worm
bearing to the slide-the gun will thus be trained by the quick gear as in the
ordinary way.
When the spur pinion is stopped the pinion will hold the toothed ring in
osition and if the worm be then driven the worm will travel round on the
oothed ring and the mounting thus be trained with the nicety required.

page_text: The worm gear can also be used to correct the position of the mounting while
the ring is being driven round by the pinion. Both gears may thus be worked
either separately or simultaneously without it being necessary to disconnect or
throw any part out of gear.
In some cases I arrange the toothed ring to turn on the fixed pivot plate of the
mounting instead of on the slide-the pinion and worm gearing therewith being
arranged to work in the ring in a similar way to that previously described.
In place of the worm and worm wheel gear a ring of spur teeth and pinion
gearing therewith might be employed the pinion being driven by a worm and
worm wheel or other gear so that the pinion is held and prevented from turning
when the mounting is trained by the quick gear.

page_text: I JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane, Southwark in
the County of Surrey 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 :-
The improvements relate to the training gear of centrally pivotted gun mountings
of that class in which the training is effected by means of a horizontal toothed
wheel attached to the slide of the mounting and consequently moving there with in
training the wheel being driven by means of a pinion gearing into it, the bearing
of the pinion being stationary.
If the toothed wheel is as heretofore rigidly attached to the slide it is difficult,
when the pinion is driven by means of hydraulic or other power, so that the
training is done quickly, to lay the gun on a given object with sufficient accuracy..
I remedy this in the following way:-Instead of attaching the horizontal wheel
rigidly to the slide I make it as a ring supported in guides on the slide and capable
of turning around the same but independently thereof. I make in the ring one
set of teeth forming a spur wheel suitable for the driving pinion (the same as for
the arrangement above described) and on the same ring a separate set of teeth
forming a worm wheel into which gears a worm of which the bearings are fixed to
the slide of the mounting; the worin being driven by suitable gearing (preferably
by hand) from the battery. On the pinion being driven pressure will be com
municated to the spur teeth and be transmitted by the ring to the worm teeth-and
consequently to the worm-and the latter being of sufficiently fine pitch (or held.
by a brake) so as not to turn with the pressure motion will be communicated by a
thrust on the worm bearing to the slide-the gun will thus be trained by the quick
gear as in the ordinary way.
When the spur pinion is stopped the pinion will hold the toothed ring in position
and if the worm be then driven the worm will travel round on the toothed. ring
and the mounting thus be trained with the nicety required.
The worm gear can also be used to correct the position of the mounting while
the ring is being driven round by the pinion. Both gears may thus be worked
either separately or simultaneously without it being necessary to disconnect or
throw any part out of gear.
In some cases I arrange the toothed ring to turn on the fixed pivot plate of the
mounting instead of on the slide-the pinion and worm gearing therewith being
arranged to work in the ring in a similar way to that previously described.
In place of the worm and worm wheel gear a ring of spur teeth and pinion
gearing therewith might be employed the pinion being driven by a worm and
worm wheel or other gear so that the pinion is held and prevented from turning
when the mounting is trained by the quick gear.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed..

page_text: •
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 show respectively section and plan of one form of the improved
training gear. The horizontal ring a is supported in the guides bc, in which it can
turn, formed on or connected with the base & of the slide of the mountings which
is trained around the centre e as a pivot. To lessen friction the ring bears against
rollers d¹ carried in bearings a formed on the base d of the slide.
On the lower part of the ring a are formed spur teeth extending around the
whole or a portion of its periphery according to the range through which the
mounting can be trained. Into these spur teeth the pinion ƒ gears. The axis of
this pinion is carried on stationary bearings on the fixed portion of the platform
or other supporting structure on which the mounting is carried. The pinion ƒ is
driven from below by hydraulic or other suitable power to give rapid training.
On the upper part of the ring a are formed worm teeth of similar extent to that
of the spur teeth-into these the worm g gears, it is supported in a bearing i fixed
in the slide of the mounting and moving therewith when trained. The worm is
driven from the battery preferably by hand by means of suitable gear connected to
the shaft h which gives motion to the bevil wheels j one of which is connected with
the worm g!
The slide of the mounting is supported by and in training turns upon rollers
which run on a racer or roller path k fixed to the platform. The rollers are either
carried in bearings on the slide or made as a ring of live rollers on the tops of
which the suitably formed under shoe of the slide rests. To give more protection
to these rollers it is preferred to arrange them below the level of the deck or
platform l.
The longitudinal thrust due to firing is taken by the rollers m supported on the
slide which press against the inside of the racer k-the upward lift being taken by
suitably fitted clips n.
On the pinion being driven pressure will be communicated to the spur teeth in
the ring a, transmitted by the ring a to the worm teeth and caused to react against
the worm.
The worm being of suitable pitch does not turn on its axis under the
pressure and motion will be communicated to the slide by the end pressure of the
worm against its bearings. Both slide and ring in this case turn together and
the gun will thus be trained by the quick gear in the ordinary way.
In order to train by fine adjustment, on the pinion f being stopped near the
desired position for firing-the pinion f is held or prevented from turning by the
engine or other machine with which it is connected-consequently the ring a is
held and prevented turning on its axis. Motion being now given to the worm g
the latter will travel round on the worm teeth carrying with it the mounting
which can thus be trained with the nicety required.
The worm g may also be driven whilst the ring a is being turned round-and
the mounting being trained by the pinion f-by which means the position may be
corrected. Both gears may thus be worked either separately or simultaneously
without it being necessary to disconnect or throw any part out of gear.
Figures 3 and 4 show respectively part longitudinal section and plan of a
centrally pivoted mounting. In this case the ring a is arranged to work round on
the raised tubular portion b of the pivot plate c. The ring a is provided with the
two rings of teeth as previously described-one for the fixed pinion d worked from
below by hydraulic or other power-and the other for the worm e worked from the
battery by means of the handle f and suitable intermediate gear.
The two gears can be worked in this case either together or separately without
it being necessary to throw any part out of gear-the training of the mounting
being effected as described in connection with the arrangement shown by Figures 1.
and 2.
Figures 5 and 6 show respectively a part section and plan of a modified
arrangement of the ring a-which consists in forming it with only spur teeth

page_text: of sufficient breadth to allow the two spur pinions b. c to gear therewith and pass
over each other in training-The pinion 6 is fixed in position and is driven by
hydraulic or other suitable power from below as in the arrangements previously
described. The pinion c is driven preferably by hand gear from the battery-
from the handle & through suitable gear and the worm e carried in bearings on the
slide the worm e driving the worm wheelf fitted on the shaft of the pinion c.
The training can be effected by working the two gears either together or
separately as in the preceding cases-the mounting being turned by the thrust
of the worm e against its bearings.
The ring a is supported in guides g h and turns against rollers i to reduce
friction.
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.) My improvement in training gear of centrally pivoted gun mountings, which
is applicable when a horizontal toothed wheel is connected with the gun slide and
is driven by a pinion actuated by any motor; and which improvement consists in
providing a secondary self locking driving gear, preferably to be operated by
manual labour, to form the connection between the said toothed wheel and the gun
slide and also when required to rotate the slide independently of the toothed wheel
substantially as described.
(2.) My improvements in training gear of centrally pivotted gun mountings
consisting in providing the same with a power gear by which the gun can be
rapidly trained and held and a hand gear by which the training may be accurately
adjusted substantially as described.
(3.) My improved training gear for central pivot gun mountings substantially as
the same are herein described and shown by the annexed drawings.
Dated this 27th dow of Tonne 100
CARPMAEL & Co.,
Agents for the Applicant.