Year: 1887

page_text: Date of Application, 30th June, 1887.
Specification Accepted, 2nd Aug., 1887.
1, JOSEPH WHITELEY of Clowes Street Chapel Street, Salford, in the County of
Lancaster Pattern Maker, 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 principal object of this invention is to simplify and improve the construction
of expanding mandrels, and to make the same applicable for chasing nuts or other
objects.
And in order that my invention may be better understood I have caused to be
appended hereunto one sheet of drawings marked with letters of reference indicating
like parts in the various figures.
Fig. 1 is a side elevation, Fig. 2 an end elevation, Fig. 3 a longitudinal section,
Fig. 4 a cross section at line -. of my improved expanding mandrel, Fig. 5 a
vertical section, and Fig. 6, a cross section at the line - of my improved expanding
tap.
In carrying out my invention and referring more particularly to Figs. 1. 2. 3. & 4.
I form the spindle A of the mandrel with a cylindrical portion a of increased
diameter. This cylindrical portion a I furnish with three or more longitudinal
grooves b the bottoms thereof forming inclined planes b.
These grooves are made to receive wedge-shaped keys c, sliding on the said inclined
planes and of T-like or other convenient section which will prevent the keys e from
falling out radially.
The spindle A of the mandrel is chased on each end of the cylindrical portion a for
the purpose of receiving a nut d and washer e respectively.
The latter are placed against each end of the keys c, which are longer than the
cylindrical portion a of the mandrel, so as to leave a free space between the ends of
the cylindrical portion a, and the washers e, for the purpose of permitting the keys c
to be forced from the right to the left or vice versa, by screwing the nuts d either
in one
or the other direction and thus expanding or contracting the mandrel
respectively.

page_text: The ends of the spindle A of the mandrel are formed with centre holes so as to
be run in or between centres, or the mandrel may be arranged to be fixed to the face
plate of a lathe..
When modifying the construction of the mandrel described, to serve as an expanding
tap & referring to Figs. 5 & 6 I arrange the wedge shaped keys c, which in this
case are chased and forin cutters to slide only radially instead of longitudinally and
radially, and the increased cylindrical portion a of the spindle A formed with
grooves having inclined bottoms, to slide longitudinally, that is to say, reverse
to what takes place in the mandrel described herein before.
The cylindrical portion a is surrounded by a cover, provided with slots" through
which the cutters è pass respectively.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :-
In expanding mandrels or taps.
1st. The combination of a spindle A, having a cylindrical portion a, of increased
diameter furnished with three or more grooves b, the bottoms of which form inclined
planes, with wedge-shaped keys c fitting into the grooves b, and sliding on the
inclined planes b', substantially as set forth.
2nd. The method of expanding or contracting the mandrel by forcing and
adjusting the keys e by means of nuts d, and washers e, employed on the spindle A,
and acting upon the ends of the keys c, substantially as described.
Dated this 28th day of June 1887
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester,
Agents to Applicant.