IMPROVEMENTS IN TOOL HOLDERS " FOR LATHES AND OTHER MACHINES
Year: 1883

page_text: LETTERS PATENT to Maximilian Carden Despard of Courtlands Esher in the
County of Surrey for an Invention of "IMPROVEMENTS IN TOOL HOLDERS
"
FOR LATHES AND OTHER MACHINES communicated to him from abroad by
Gavin Sibbald Jones of Cawnpore India
PROVISIONAL SPECIFICATION left by the said Maximilian Carden Despard
at the Office of the Commissioners of Patents on the 17th November 1883.
MAXIMILIAN CARDEN DESPARD of Courtlands, Esher in the County of Surrey
"IMPROVEMENTS IN TOOL HOLDERS FOR LATHES AND OTHER MACHINES." [com-
municated to him from abroad by Gavin Sibbald Jones of Cawnpore India]
This invention has for its object improvements in tool holders for lathes and
other machines. For this purpose I make the head in which the tool is to be fixed
in the form of a cylinder which has a stem projecting from one of its ends. The
tool is passed at any desired angle through slots or holes formed through two
opposite sides of the cylinder.
Inside the cylinder is a loose plug, the plug has a slot bored through it at the
same angle for the tool to pass through. When the tool has been passed through the
slots in the cylinder and plug a screw bolt which is made to screw longitudinally
through the stem of the cylinder is turned by means of a head on its upper end.
and the inner end of the screw bolt is so made to bear against the plug, and
thereby to lock and hold the tool. The stem is of smaller diameter than the
cylinder and has a screw thread cut on its exterior; it is made to pass through a
hole formed through the bar or shank by which the head is to be carried.
The end of the bar or shank is so formed that not only may the top of the
cylinder fit against its underside, but also so that one side of the upper part of the
cylinder may fit against it as well.
To lock the head to the bar or shank, a cylindrical nut is screwed on to its screw
stem. The nut is formed with a collar around its upper end by which it can be
turned. The collar may be made to bear against the upper side of the bar or shank
and thereby draw the upper end of the cylindrical head against its under side. Or
the nut may be conical on the exterior and made to fit in a corresponding recess in
the shank or stem. In this latter case the nut may be split longitudinally so that
when screwed up it may grip the stem of the swivel head and so fix it very
securely. The screw threads may be right or left handed for general use.
handed is preferred for a lathe the cut being from right to left a heavy cut.will
then have a tendency to bind the swivel head faster and prevent the tool from
shifting its position.
Left

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Maximilian Carden Despard in the Patent Office on the 16th May
1884.
"
MAXIMILIAN CARDEN DESPARD of Courtlands Esher in the County of Surrey
"IMPROVEMENTS IN TOOL HOLDERS FOR LATHES AND OTHER MACHINES (A com-
munication from abroad by Gavin Sibbald Jones of Cawnpore India)
This invention has for its object improvements in tool holders for lathes and other
machines. For this purpose I make the head in which the tool is to be fixed in the
form of a cylinder which has a stem projecting from one of its ends. The tool is
passed at any desired angle through slots or holes formed through two opposite
sides of the cylinder
Inside the cylinder is a loose plug, the plug has a slot bored through it at the
same angle for the tool to pass through. When the tool has been passed through the
slots in the cylinder and plug a screw bolt which is made to screw longitudinally
through the stem of the cylinder is turned by means of a head on its upper end
and the inner end of the screw bolt is so made to bear against the plug and
thereby to lock and hold the tool.
The stem is of smaller diameter than the cylinder and has a screw thread cut on
its exterior; it is made to pass through a hole formed through the bar or shank by
which the head is to be carried.
The end of the bar or shank is so formed that not only may the top of the
cylinder fit against its underside but also so that one side of the upper part of the
cylinder may fit against it as well.
To lock the head to the bar or shank a cylindrical nut is screwed on to its screw
stem. The nut is formed with a collar around its upper end by which it can be
turned. The collar may.be made to bear against the upper side of the bar or shank
and thereby draw the upper end of the cylindrical head against its underside. Or
the nut may be conical on the exterior and made to fit in a corresponding recess in
the shank or stem. In this latter case the nut may be split longitudinally so that
when screwed up it may grip the stem of the swivel head and so fix it very
securely. The screw threads may be right or left handed for general use.
handed is preferred for a lathe the cut being from right to left a heavy cut will
then have a tendency to bind the swivel head faster and prevent the tool from
shifting its position.
•
Left
The drawings hereunto annexed shew a tool holder constructed as above
described.
Figure 1 shews a side elevation, Figure 2 a plan and Figures 3 and 4
longitudinal sections of tool holders constructed as above described. In the
longitudinal section shewn at Figure 3 the swivel head is shewn as being locked
and held by a nut coned externally and fitting into a corresponding recess.-in
Figure 4 it is shewn as being locked and held by a cylindrical nut formed with a
collar to bear against the top of the shank.
In these figures A is the cylindrical swivel head fitted accurately into the
shank E. B is a cylindrical plug fitting loosely into the interior of the swivel
head. C is a screw bolt screwing longitudinally through the stem of the swivel
head so, that its inner end may be made to bear against the top of the cylindrical
plug. D is a nut screwing on to a screw thread cut upon the.exterior of the stem
of the cylindrical holder. In Figure 4 this nut is shewn to be made cylindrical and
with a collar or shoulder around it to bear against the top of the shank E and so
to draw the top of the cylindrical swivel head against the underside of this shank.

page_text: In Figure 3 the nut is shewn to be coned externally to fit within a correspondingly
coned recess in the shank-in this case the tapering end of the nut may if desired
be split longitudinally so that when screwed on to the screw stem of the swivel
head, the sections into which it is divided may be pressed inwards and made to bind
against and nip the screw stem as well as to draw the top of the swivel bead
against the underside of the stem. Preferably however I prefer to form it simply
as a coned nut to fit into a corresponding coned recess.
F is the tool passed through inclined slots in the swivel head and in the plug
which fits within it.
When the tool is inserted into its place in these slots it is locked and held by
screwing inwards the screw bolt C.
By constructing tool holders as above described with a screw bolt to lock and
hold the tool in the swivel head and a separate screw nut to lock and secure the
swivel head to the shank in place of employing one screw nut only to effect both
these purposes as in swivel head tool holders heretofore proposed not only is the
tool held more securely in the swivel head but the swivel head also can be locked
and prevented from turning in a much more secure manner than was heretofore
practicable.
The tool also in my tool holder being held by being forced downwards against
the bottom of the slot in the cylindrical head any downward strain upon the tool
when cutting will only tend to hold the tool the tighter.
Having thus described the nature of my said invention and the manner of
performing the same I would have it understood that what is Claimed is :-
First The construction of swivel head tool holders substantially as herein before
described and illustrated in the drawing annexed.
Second-The construction of tool holders with a cylindrical swivel head carrying
an internal plug through slots in both of which the tool is to be passed and with a
screw bolt to screw through the stem of the swivel head and bear against the plug
so as to grip and hold the tool and also with a separate screw nut to screw on to
the exterior of the stem of the swivel head and lock the swivel head to the shank
substantially as herein before described.
In witness whereof I the said Maximilian Carden Despard have hereunto set my
hand and seal this third day of May in the year of our Lord One thousand eight
hundred and eighty four.
M. C. DESTAND
(18.)