Year: 1897

page_text: Date of Application, 3rd Mar., 1897
Complete Specification Left, 3rd Dec., 1897-Accepted, 8th Jan.,
1898
I, JAMES GARVIE, of Devanha House, New Southgate, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in lathes and has reference more particu-
larly to lathes such as employed for turning projectiles or shells.
An important feature of the invention consists in providing the lathe with two
saddles or slide rests for simultaneously turning both the cylindrical portion of
the shell and also the curved or conoidal point thereof.
A further feature consists in the special means employed for operating that one
of the saddles or slide-rests by which the point of the shell is turned.
According to the said invention I provide the lathe, which in its general con-
struction resembles an ordinary shell lathe, with a bracket at the back of the bed,
and upon this bracket I arrange an adjustable slotted bar parallel with the lathe
bed. In the slot of this bar is adjustably secured a pin which forms the pivot of
an arm or link connected with the upper portion of the saddle for turning the shell
point. This saddle or slide-rest differs from an ordinary saddle in the fact that
the said upper portion, namely that portion which carries the tool holder is unpro-
vided with any traversing screw, the aforesaid pivoted arm serving to impart the
necessary transverse movement to such upper portion. According to another
arrangement I provide the lathe bed with two T-slots extending the entire length.
thereof, and in combination with these slots I provide a bracket, which I can thus
fix in any position required, so obviating the use of the parallel slotted bar above
referred to.
The arrangement of the parts is such that the pivoted arm lies transversely or
at right angles to the lathe bed, when the saddle with which it co-operates is in the
position for commencing the cut on the lathe point. When therefore the said
saddle is moved longitudinally along the lathe bed, the arm in turning upon its
centre draws the upper portion of the saddle transversely across the lathe bed and
consequently the tool receives a compound motion, the particular curvature of
which depends upon the length of the arm and the relative position of the centre
pin on which it turns, and by suitably adjusting these any desired curvature can
be obtained.

page_text: same is to be performed to be particularly described and ascertained in and by
the following statement:-
This invention relates to improvements in lathes and has reference more particu-
larly to lathes such as employed for turning projectiles or shells.
An important feature of the invention consists in providing the lathe with two
saddles or slide rests for turning simultaneously the cylindrical portion and the
curved or conoidal point of the projectile.
A further feature consists in the special means employed for operating the saddle
or slide-rest by which the point of the projectile is turned.
According to the said invention I provide the lathe, which in its general con-
struction resembles an ordinary projectile lathe, with an adjustable bracket at the
back of the bed. This bracket carries a pin which forms the stationary pivot of an
arm or link connected with the upper portion of the saddle for turning the point
of the projectile and serving to impart the necessary transverse movement to such
upper portion.
In some cases in place of an arm or link I employ a plate or disc provided with
holes the distances between which correspond to the lengths of the arms or links
required for different sized projectiles. One such plate therefore will serve the
purpose of several of the aforesaid arms or links.
In order that the invention may be clearly understood and readily carried into
effect I will proceed to describe the same by aid of the accompanying drawings, in
which
Figure 1 is a plan, and
Figure 2 a transverse section of so much of a projectile lathe as is necessary for
the purpose of explanation.
Figure 3 is a plan and
Figure 4 is a transverse section showing the modified arrangement in which a
perforated disc takes the place of the arm or link.
Referring more particularly to Figures 1 and 2, A is a portion of the lathe bed;
B indicates the projectile or shell the base of which is secured in a suitable chuck
(not shown); C is the saddle or slide rest for turning the point of the shell; C¹ is
the upper transversely sliding portion thereof; and C³ is the tool holder or clamp.
It will be seen that the upper portion C¹ is provided with a tool-adjusting screw
or screws C3 but that the usual traversing screw is omitted.
D is the saddle or slide rest for turning the cylindrical portion or body of the
projectile. The slide rest is of ordinary construction and is operated by the
traversing screw D' of the lathe in the usual manner. This screw 11 also serves to
impart longitudinal motion to the saddle or slide rest C.
a is the adjustable bracket above referred to. This bracket has a vertical face a¹
through which pass bolts a³ engaging with a pair of T-slots a³ extending the whole
length of the bed. The face a¹ also has ribs or projections a adapted to fit into
the mouths of the slots a³ to give greater support to the bracket, and the portion
of the back of the bed against which the bracket bears, is faced up so that the
bracket can be easily moved along the bed when required.
is the stationary pivot or pin which the bracket serves to carry. This pivot
is formed or fixed on a block b and the bracket has a horizontal face a on which
the block b' is adapted to slide at right angles to the lathe. The block and bracket
are connected by a bolt 62 working in a T-slot as in the face as of the bracket, this
arrangement permitting of movement of the pivot towards or away from the
lathe bed.
c is the arm or link which works on the pivot 6 and which is connected to a
pin 6* on the upper portion C¹ of the slide rest C.
The pivoted arm c is preferably caused to lie transversely or at right angles to
the lathe bed when the saddle C is in the position for commencing the cut on the
point of the projectile. When therefore the said saddle is shifted along the lathe
bed by the screw D', the arm in turning upon the pivot b draws the upper portion
of the saddle transversely across the lathe bed and consequently the tool receives

page_text: a compound motion, the particular curvature of which depends upon the radius
of motion of the pin 6* about the pivot b, or in other words on the effective length
of the arm e.
By suitably adjusting the said radius and the position of the pivot
any desired curvature can be obtained.
Obviously at the same time that the tool of the slide rest C is acting on the point
of the projectile, that of the slide rest D can be turning the cylindrical portion
thereof and thus a great economy in time is effected.
Referring now to the arrangement shewn in Figure 3 and 4, which is similar
to that hereinbefore described, it will be obvious that although only the slide rest C
is shown, yet a second slide rest 1 can be employed if desired.
c* is the plate or disc which takes the place of the arm or link c
shown in the previous arrangement, while 22 are the pivot holes
formed in the disc. Each of these holes is adapted to fit over the pivot pins b
and 6 so that the position of the disc can be changed at will. The distances
between the holes correspond to the various radii required for giving different
curvatures for projectiles of different sizes.
Thus it is only necessary to insert the pins 6 6 in a different pair of holes to
obtain the proper curvatures for a shell of a certain size.
Before commencing to turn the point of a projectile by means of this construc-
tion of saddle, the pins b and 6* are preferably brought into a line at right angles
to the lathe bed, the action being similar in all respects to that of the arrangement
shown in Figures 1 and 2.
It will be seen that in this case there is only one T-slot a³ at the back of the bed.
I find that for smaller sized lathes this is quite sufficient, the two slots being more
especially applicable to heavy lathes.
It will be seen that whichever arrangement be used the change in the path of
the tool can be much more readily effected than in a lathe where the transverse
movement of the tool is imparted to the tool by a screw.
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 lathe having two saddles or slide rests adapted to act simultaneously the
one on the point and the other on the body of a projectile substantially as described
with reference to the accompanying drawings.
2. A lathe of the kind referred to in the preceding claim, wherein the slide rest
which acts on the point of the projectile has its transversely moving portion con-
nected with a stationary pivot pin, substantially as and for the purposes described.
3. A lathe constructed and operating substantially as hereinbefore described
with reference to Figures 1 and 2 or to Figures 3 and 4 of the accompanying draw-
ings and for the purposes specified.
Dated this 3rd day of December 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.