An Improved Expanding Clutch or Chuck for Fixing Metallic Discs to and Releasing them from Patterns in Lathes.
Year: 1889

page_text: Date of Application, 23rd Dec., 1889-Accepted, 22nd Feb., 1890
COMPLETE SPECIFICATION.
An Improved Expanding Clutch or Chuck for Fixing Metallic Discs
to and Releasing them from Patterns in Lathes.
I, THEODOR SUCHLAND, of No. 3 Jahn Strasse, in the City of Berlin, Germany,
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 :-
My invention relates to an improved expanding clutch or chuck for fixing metallic
discs to and releasing from patterns in lathes. The hitherto customary attachments
possess the disadvantage that in order to release the same and remove the metal
operated on from the form or pattern, the lathe must be stopped, and when the lathe
is driven by motive power the attaching nut must be removed from the mandril by
turning the same to the left. If on the other hand the lathe is driven by a treadle
the removal of the attaching nut is still more inconvenient for the workman, for the
reason that in order to save time he must reverse the rotation of the lathe, grasp the
nut with the hand, and turn same from the threads on the mandril.
In order to attach a new disc or piece of metal to be operated on to the mandril by
means of the attaching nut, the lathe must be rotated to the right, whereby not only a
great loss of time ensues but the workman is fatigued. When my improved expanding
clutch is employed the lathe can be continuously rotated in the same direction, and
the above mentioned disadvantages are not only overcome, but the production of the
pressed articles is enormously increased.
In the accompanying drawing,
Figure 1 is a longitudinal section of my improved expanding clutch in fixed
condition and screwed against the metal or the like to be operated on.
Figure 2 is a longitudinal section of my improved clutch in opened condition ready
for the removal.
Figure 3 is an elevation of the muff n with the inclined surface o for releasing the
grip of the clutch on the screw bolt or mandril.
Figure 4 is a representation of the clutch jaws partly in side view and partly in
section.
Figure 5 is a vertical section on the line x-x in Figure 2 with open
Figure 6 is a like section with the clutch jaws closed.
clutch.
The form or pattern b is, as usual, screwed to the mandril a on the front end of the
shaft of the lathe and in front of this is fixed the work piece c to be operated on, this
being held firmly in position by the expanding clutch.
My improved expanding clutch is constructed as follows:-
The clutch for holding the work piece in position consists of two or more jaws d
provided with appropriate female threads which gear into the male threads on the
mandril, the jaws forming, when in closed condition, a nut and their ends forming
leaf springs e joined at their rear ends to form a collar f and ending in a stem g,
provided at its extreme end with screw threads for receiving a washer and nut
or jam nut. The forward ends of the jaw d are provided at d¹ with inclined
surfaces and the leaf springs e have the tendency to push the jaws of the nut-
like clutch outwards, so that the clutch can be readily pulled off the mandril a,
Figure 2.
The clutch d, e, g, is arranged in a cylinder h with a broad head i at its rear
end is open whilst the forward end comes in contact with the work piece and in
closed condition retains the jaws of the clutch in snug gear with the threads on
the mandril.
.
The head is provided with a central boring to allow the free passage of the
stem which is embraced between the rear surface of the head i and the washer on
said stem by
gk, which has the tendency to draw the jaws of the

page_text: expanding clutch to the rear and within the cylinder h. A handle / hollowed out to
receive the stem g and spring k is screwed or otherwise attached to the head i of the
cylinder h. The drawing represents the attachment by means of screws m.
Surrounding the cylinder and rotable with the same is a muff n of desired form
and size which lies at the rear end on the flange to the head i of the cylinder h. The
forward surface of the muff n forms an incline o which gears with one or more pins or
screw pegs 9 screwed or otherwise fixed to the parts of the clutch and running
through longitudinal slots p of the cylinder h.
In working with my improved expanding clutch the same is screwed onto 'the
mandril a in the customary manuer until the front edge or surface of the jaws d,
which are held in snug contact with each other by the cylinder h so that they have
the form of a nut, press the work piece c firmly against the mould or patterns b.
When the press or other work is finished the same and also the clutch attachment
can be readily removed from the mandril a without stopping the lathe or reversing
the movement of the same. In order to carry out the aforesaid operation the work-
man grasps the loose muff n and presses at the same time slightly in the direction of
the arrow in Figure 2, thus preventing the muff from rotating.
The jaws d and cylinder continuing their rotary movement will cause one of the
pins or pegs q attached to the jaws d to run up the incline o of the muff n, so as to
release the jaws d from their gear with the thread of the mandril a, said jaws being
extended under the influence of the springs e, so that the clutch attachment can be
readily withdrawn from the mandril a, Fig. 2. The spring k, which was put under
tension when the jaws d were extended beyond the surface of the cylinder h, will,
when the pin or peg q has passed the highest part o' of the incline o, draws the jaws
to the rear within the cylinder h, so that they are again in snug contact so as to form
a nut ready to be again screwed onto the mandril.
It will be evident to all versed in the art that my improved expanding clutch
attachment can be applied for attaching other than discs to be pressed onto pattern
moulds when it is not necessary that the work piece be fixed between centres
and that short objects not subject to much vibration can be turned or polished in
a lathe and the time saved, which is usually occupied in reversing and stopping
the lathe.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
:-
1-A clutch-like attaching device for work pieces, characterised by the arrange-
ment of the exteriorly conical or partially conical clutch jaws d, divided in their
entire length into 2 or more parts, the separate parts of which form leaf springs e,
and end in a guide rod g, in combination with a cylinder h and a helical spring k for
drawing the parts of the clutch d within the cylinder h, whereas when the jaws of the
clutch & are extended beyond the cylinder h by means of the pin or pins 9 operating
on the incline surface o of a muff n, the jaws will be expanded by the leaf springs e, so
as to allow the clutch to be rapidly removed from the threaded mandril, substantially
as and for the purpose set forth and shown.
2: The construction and application of the clutch d consisting of two or more
aws d with inclined surfaces d', leaf springs e, stem and spring k, substantially as
and for the purpose set forth in the foregoing specification and shown in the accom-
panying drawings.
3: The general combination and construction of the respective parts, together
forming my improved expanding clutch, substantially as set forth in the foregoing
specification, and illustrated by the accompanying drawings.
Dated this 23rd day of December 1800