An Improved Appliance for Holding and Releasing Tools or Mandrels in Machine Tools and Machines.
Year: 1890

page_text: Date of Application, 28th Feb., 1890-Accepted, 29th Mar., 1890
COMPLETE DIELEIVATION
An Improved Appliance for Holding and Releasing Tools or Mandrels
in Machine Tools and Machines.
I, ALFRED MUIR of the firm of William Muir and Co. Machine Tool Makers, of
Brittania Works, Manchester in the County of Lancaster, Mechanical 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:
It is a common practice in engineering to make a taper hole in a machine spindle
into which hole the taper shank of a mandrel or a cutting tool such as a drilling,
boring, milling or other tool is fitted and secured.
To enable the taper shank of a tool to be held and released from the spindle it is
usual to cut a slot through the spindle intersecting the taper hole at or near its end
into which slot the flat end of the shank of the tool projects. The tool is held by
To release
driving its taper shank into the conical hole in the spindle or vice versa.
the tool a key or wedge is driven into the slot so as to bear upon the end of the shank
and drive it out.
Other well known methods of holding and releasing the taper shanks are employed
as for example a cotter passing transversely through a slot in the spindle and a
corresponding slot in the shank.
There are many objections to these plans among others it necessitates the shanks of
the tools being of nearly uniform length. Again in some cases the taper or partly
taper and partly parallel hole in the machine spindle must be extended to an
inconvenient length which necessitates shanks of the same inconvenient size in order
to permit the wedge to be used to release the tool through the slot made for the
purpose.
The chief object of my invention is to overcome these difficulties and I accomplish
this by means of the improved tool holding and releasing appliance illustrated by the
accompanying Sheet of Drawings in which-
Figure 1 is a sectional elevation of part of the spindle bearing of a machine tool
or machine. Fig. 2. is a plan view looking from the underside of the same. Figs. 3
and 4 are similar views respectively to Figs. 1 and 2 shewing an alternative
arrangement, and-
Figs. 5 and 6 are similar views shewing another alternative arrangement.
Similar letters refer to similar parts throughout the several views.
To illustrate my invention I have only shown the outline of part of the spindle
bearing of a machine tool or machine no further portion of the machine being
necessary for the purpose of explanation.
Referring first to Figs. 1 and 2-a is the taper spindle fitted and free to revolve in
a hole of corresponding taper in the bearing 6 of the machine, a small portion only
of the bearing being shown. In the machine spindle a, is a taper hole to receive
the correspondingly tapered shank c of the tool the cutting portion of which is not
shown, but which would either be attached to the screwed portion c¹ of the shank c or
otherwise connected or formed in one piece with the shank c. A screw thread is cut
upon the reduced end of the spindle a upon which is screwed a collar d provided
with holes d¹ for a bar or lever by which the collar can be turned as required. There
is a central hole through the collar d and this hole is threaded to correspond in size
with a similar thread c cut upon the shank c as shewn in Fig. 1.
A convenient plan of applying this collar d is to screw it on to the spindle a then
the shank c is put into the taper hole in the spindle and screwed into the collar d
until the shank fits the taper hole in the spindle the locking or driving pressure is
applied by means of a lever inserted into one of the holes d to tighten the shank.
ונ.D

page_text: When it is desired to withdraw the shank c from the machine spindle a the collar d
is turned slightly in the reverse direction by means of the lever when the shank c
is immediately slackened and can be readily removed by unscrewing it from the
collar d.
In Figs. 3 and 4 the end of the machine spindle a is grooved at a¹ in place of
being screwed, the collar d has a flange d" partly cut away as indicated clearly by
dotted lines in Fig. 4 to allow it to be placed over the spindle a in the groove a ; a
hole is made and screw threaded in the bottom of the collar to receive the screwed
portion of the shank c.
In order to secure the taper shank c in the spindle a the collar d is put into its
position on the end of the spindle the shank c is placed in the taper hole and screwed
into the collar d until it fits the taper hole a lever being applied to a hole d to turn
the collar and draw up the shank firmly into the taper hole as before described.
To release the taper shank c it is only necessary to move the collar d slightly in the
reverse direction.
:
In the alternative arrangement Figs. 5 and the spindle a is threaded at a' and the
collar d also threaded as in Figs. 1 and 2 while a recess d¹¹ is made in the lower part
of the collar to fit over a collar c¹¹ formed upon the shank c: or vice versa the recess
might be in the shank and the projection on the collar. In applying this arrangement
the collar d is first placed upon the shank c which is then thrust into the taper hole in
the machine spindle a the threaded portion of the collar d engages with the thread a¹
until the two cones fit when a lever is applied to one of the holes d¹ to turn the
collar d and draw up the shank c until it is firmly secured in the spindle a.
To release and remove the shank c the movement of the collar d is reversed to
unscrew it from the spindle a when the shank is set at liberty.
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 tool holding and releasing appliance consisting of a collar adapted to be
connected to the prepared spindle of a machine tool or machine and also to the
prepared shank of the mandrel or cutting tool said shank being tapered to fit in a
taper hole in the machine spindle, so that by turning the collar the shank can be
secured in or relased from the machine spindle substantially as herein set forth.
2. The combination with the spindle of a machine tool and the shank of a cutting
tool of the collar d substantially as herein described and as illustrated by the Drawings
annexed..
Dated this 27th day of Fahun 1900
H. B. BARLOW,
17, St. Ann's Square, Manchester, Agent for Applicant.