Improvements in Adjustable Conical Mandrels.
Year: 1892

page_text: Date of Application, 26th May, 1892
Complete Specification Left. 22nd Feb., 1893-Accepted, 25th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Adjustable Conical Mandrels.
THOMAS HUMPAGE, 12 Greenway Bush Lane, Ashton Gate, Bristol, Engineer,
and HERBERT INNIS JACQUES 24 Durdham Park, Bristol, Engineer do hereby
declare the nature of this invention to be as follows:-
This invention relates to adjustable conical mandrels for use, for all general
engineering purposes, for holding work, which has parallel or taper bores, requiring
to be turned, faced, ground or otherwise suitably treated. It consists of a
cylindrical mandrel of steel or other suitable metal, which is turned true throughout
its entire length. On this mandrel are placed two cones, which are made of steel
or other suitable metal. These cones are either solid or cored out, and are bored
an accurate fit for the before-mentioned cylindrical mandrel, and turned truly taper
for a portion of their length. The remainder of their length is turned parallel
and screwed externally on a smaller diameter than the largest diameter of the
cone, and the portion of metal joining these two diameters is turned to a face
inclined at the same angle as the threads of the external screw, and forms a
continuation of the last of them. The cones are cut through parallel to the
cylindrical mandrel by one or more saw cuts thus in some cases dividing them into
two or more parts. Two nuts made of steel or other suitable metal are tapped or
cut to fit the screws on the before-mentioned cones. On each side of these nuts
inclined faces are turned which fit the inclined faces on the cones. A collar made
of steel or other suitable metal, is bored an accurate fit for the before-mentioned
cylindrical mandrel, and inclined faces turned on each side of it, to fit the inclined
faces on the nuts. It is then cut through parallel to the cylindrical mandrel by a
saw cut, and is provided with a bolt which closes it firmly on the cylindrical
mandrel.
This adjustable mandrel is used as follows;-one of the cones is placed on the
cylindrical mandrel in any desired position, and the nut screwed up. When the
two inclined faces meet the cut portions of the cone are forced together, and it
grips the cylindrical mandrel firmly. The work requiring to be operated on is then
passed onto the cylindrical mandrel and one end fitted on the cone. The other
cone, with the nut in position, is then placed on the cylindrical mandrel, small end
first, and fitted to the opposite end of the work to that held by the first mentioned
The split collar is then brought up to the back of this second cone and
caused to grip the cylindrical mandrel. The nut is then unscrewed on the second
mentioned cone, and as soon as the inclined face on it meets the inclined face on
the collar, the cone is forced into the work to be held, and at the same time caused
to grip the cylindrical mandrel. The nut can then be screwed away from the
collar, and caused to lock the cone to the cylindrical mandrel. The work is thus
held firmly and truly central on the cylindrical mandrel.
cone.
as
We sometimes dispense with the use of the collar, fixing the first cone
described, driving the second cone in tightly, and securing in position by the nuts,
all as before described.
We sometimes screw the mandrel externally at one or both ends, and the whole
or part of its length, and tap one or both of the .cones internally. The method of
using is as before described, but the use of the collar is dispensed with, and the
tightening of the second cone effected by turning it upon the thread cut on the
cylindrical mandrel, then either leaving it free to tighten automatically, or securing
it in any desired position by the nut as before described.
We sometimes fix the first cone as described, or by keying it to the cylindrical

page_text: mandrel, and provide for the adjustment of the second cope, by either drilling holes
at intervals in the cylindrical mandrel, providing a pin to pass through same, which
acts as a stop in the same manner as the collar previously described; or by forming
a rack in the cylindrical mandrel, and a worm in the cone gearing into it; or by
a traversing screw in a slot in the cylindrical mandrel, and a nut working on same
attached to the cone; or by turning an inclined face on the back of the cone,
tapping the collar internally to screw on the thread cut on the cylindrical mandrel,
and turning an inclined face on the collar to fit that on the cone.
Dated this 25th day of May 1892
THOMAS HUMPAGE.
HERBERT INNIS JACQUES.
COMPLETE SPECIFICATION.
Improvements in Adjustable Conical Mandrels.
THOMAS HUMPAGE, of 12 Greenway Bush Lane, Ashton Gate Bristol Engineer
and HERBERT INNIS JACQUES, of 24 Durdham Park Bristol, 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 :-
This invention relates to adjustable conical mandrels for use, for all general
engineering purposes, for holding work which has parallel or taper bores, requiring
to be turned faced, ground or otherwise suitably treated. It consists (Fig. 1) of a
cylindrical mandrel (A) of steel or other suitable metal which is provided with a
recessed centre at each end and turned true throughout its entire length. Two
cones (B) made of steel or other suitable metal are bored an accurate fit for the before
mentioned cylindrical mandrel (A), and are turned truly taper for a portion of their
length (C). The remainder of their length (D) is turned parallel and screwed exter-
nally on a smaller diameter than the largest diameter of the taper part (C), and the
portion of metal (E) joining these two diameters is turned to a face inclined at the
same angle as the threads of the screw (D) and forms a continuation of the last of
them The cones are cut through longitudinally by one or more saw cuts extending
either the whole or part of their length. Two nuts (F) made of steel or other
suitable metal are tapped or cut to fit the screws (D) on the before mentioned
cones. On each side of these nuts inclined faces (G) are turned, which fit the
inclined faces (E) on the cones. A collar (H) made of steel or other suitable
metal is bored an accurate fit for the before mentioned cylindrical mandrel (A) and
an inclined face (I) turned on each side of it, which fits either of the inclined
faces (G) on the before mentioned nuts (F). It is then cut through longitudinally
on one side by a saw cut, and is provided with a screwed bolt (J) which is capable
of closing the cut parts together. This adjustable mandrel is used as follows; one
of the cones (B) is placed on the cylindrical mandrel (A) in any desired position,
and the nut (F) screwed up. When the inclined face (G) on the nut meets the
inclined face (E) on the cone, it tends to close the cone causing it to grip the
cylindrical mandrel (A) firmly. The work requiring to be operated on is then
passed on the cylindrical mandrel, one end fitting on the before mentioned cone.
The second cone with the nut (F) in position is then passed on the cylindrical
imandrel (A) the small end fitting into the opposite end of the work to that held by
the first mentioned cone. The split collar (H) is then passed on the cylindrical
mandrel (A) and brought up to the back of the second mentioned cone and the
bolt (J) screwed up, causing the collar to grip the cylindrical mandrel. The
nut (F) on the second mentioned cone is then unscrewed and as soon as the inclined
face (G) meets the inclined face (I) on the split collar, it forces the cone (B) into
the work to be held, at the same time causing it to grip tightly on the cylindrical
mandrel. The nut (F) can then be screwed away from the collar (H) and caused

page_text: to lock the second mentioned cone as previously described. The work to be
operated on is thus held firmly and truly central on the cylindrical mandrel (A).
We sometimes dispense with the use of the collar (H), fixing the first cone (B)
as described, driving the second cone in tightly, and securing in position by the
nuts (F) all as before described.
We sometimes (Fig. 2) screw the mandrel (A) externally at one or both ends
and the whole or part of its length, and tap or cut one or both the cones (B)
internally. The method of using is as before described, but no collar is required,
the tightening of the second cone being effected by turning it upon the thread cut
on the cylindrical mandrel (A), then either leaving it free to tighten automatically,
or securing it in any desired position by the nut (F) as before described.
We sometimes (Fig. 3) fix the first cone (B) as before described for Fig. 1. and
provide for the adjustment of the second cone by drilling holes (L) at intervals in
the cylindrical mandrel (A) and provide a pin (M) to fit same. This pin acts as a
stop in the same manner as the collar (H) previously described, and the adjustment
and tightening of the second cone is effected in a similar manner to that previously
described for Fig. 1.
We sometimes (Fig. 4) cut a segment of a screw thread in a concave groove (N)
in the cylindrical mandrel (A). The cones (B) are turned taper for a portion of
their length, bored & split as previously described, but in place of the external
screw threads (D) & inclined faces (E), the portions (0) are turned parallel and
recesses (P) provided into which worms (Q) fit, and gear with the screw threads
cut in the groove (N). A hole is drilled through each worm and also through the
ends of the recesses (P) and pins (R) are provided, which pass through these holes
and secure the worms (Q) in place. A hexagon shoulder (S) is provided on each
worm to suit a spanner, and by turning the worms (Q) in either direction by means
of this spanner, the cones (B) are caused to move along the cylindrical mandrel (A).
The method of using is similar to that described in (Fig. 1); the pins (R) and
worms (Q) are withdrawn from the cones (B), and the work to be operated on, and
cones are passed on to the mandrel (A) into any desired position. The worms (Q)
& pins (R) are then inserted in the cones (B) and one of the worms turned by
means of the spanner. This forces the cone (B) along the cylindrical mandrel (A)
and into the work to be held, and causes both cones to firmly grip the mandrel (A.)
as the second cone cannot move owing to the locking of its worm with the screw
thread cut in the groove (N). A reversal of this process withdraws the cone (B)
and leaves the work free to be taken off the cylindrical mandrel (A).
We sometimes (Fig. 5) cut slots (T) in the cylindrical mandrel (A), turn the
cones (B) taper as before, split same and provide a traversing screw (U) fitted with
a nut or head (V) by means of which it can be turned in either direction. The
action is as before described, the nut or head (V) engages in one of the slots (T) in
the cylindrical mandrel (A), and by turning this traversing screw (U) the cone (B)
is caused to move along the cylindrical mandrel (A) in either direction.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
(1). The combination of an interior cylindrical mandrel and two adjustable cones
for the general purposes set forth in the Specification, and substantially as described
therein, and shown in Figs. 1 to 5.
(2). The several means of adjusting the said cones on the cylindrical mandrel
substantially as described in the Specification and particularly shown in Figs. 1
to 5.
Dated this 01st do- of Wah 1000
THOMAS HUMPAGE.
HERBERT INNIS JACQUES.