Improvements in and relating to Screw Gear for Quick Return Vices and like Mechanism.
Year: 1898

page_text: Date of Application, 19th Mar., 1898-Accepted, 4th June, 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Screw Gear for Quick Return Vices
and like Mechanism.
I, OTTO WEISE, of 38A, Furstenweg, Ascherleben, in the Empire of Germany,
Works Manager, 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 that class of mechanism employed in putting screw
gearing into and out of action, and its object is to provide means for the rapid
adjustment of the gripping jaws in engineers or joiners bench vices and the like
or the quick return of the screw in other forms of mechanism as for example in
drills.
The invention consists generally in mounting the screwed spindle in a bush in
which it slides longitudinally but upon rotation carries the bush round owing
to a key way and feather connection between the two, and in so forming one
collar of the bush with a pawl shaped tooth that rotation in one direction acts upon
a specially formed sliding nut to throw the screw out of gear but rotation in the
reverse direction allows the nut to come into gear again.
The mode of carrying the invention into effect is illustrated in the accompany-
ing sheet of drawings as follows,―
Figure 1 is a longitudinal section showing the nut in gear.
Figure 2 is a transverse section with the disengaged position of the nut indicated
by dotted lines.
Figure 3 is a plan partly in section.
Referring to the drawings.-The screwed spindle a is carried in a bush b and
while it is free to move longitudinally therein it is attached by a feather c so that
a rotation of the screw also revolves the bush. On the front side of the wooden
frame work m of the joiner's bench a bracket f is attached and opposite to this
on the other side a plate h is fixed and the bush bis carried in suitable bearings
formed in these two pieces. A half nut e slides in a T shaped groove formed
between the projections f3 of the bracket f and this nut carries a spring pawl d
which engages under certain conditions with a pawl shaped tooth 62 formed on
one end of the bush b.
When it is desired to keep the screw spindle in gear and to operate it as a means
of gripping an object, the spindle a is turned contra clockwise relatively to
Figure 2. The nut e having a slight clearance (as shown in Figure 3) in its
T-headed slide moves slightly forward and a chamfered portion comes under
a corresponding chamfer formed on the portion fl of the bracket. The nut e is
prevented from rising by the chamfer and the rotation of the bush and its pawl
portion 62 only forces the pawl d back against its spring i into a recess and does
not lift the nut out of gear.
To throw the nut e out of gear the spindle a is rotated in a clockwise direction
until the projection 63 engages with the spring pawl d and as the nut also moves
slightly backwards and clears the chamfer f, the projection 63 and pawl delevate

page_text: the nut into the position shewn in dotted lines at Figure 2 out of gear with the
screw. The screw spindle a can now be displaced longitudinally in the bush b
so that a rapid adjustment of this spindle with its attachments may be made.
When the adjustment has been made a further rotation of the screw in the same
direction frees the pawl and allows the nut e to drop back into gear by its own
weight.
It is evident that this improved mechanism can be applied to all forms of vices
or presses in which a screw is employed and also may be adapted to drills or machine
tools where a quick return or rapid adjustment of a screwed spindle is necessary
and all without departing from the subject of the present invention.
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,-In screw gear for quick return vices and like mechanism the provision of
a bush in which the screw can slide longitudinally but is keyed on revolving so
that rotation in one direction causes a projection on the outer side of the bush to
engage with a spring pawl placed in the half nut with which the screw gears and
elevate it out of gear and rotation in the opposite direction allows the bush to
drop back into gear all as a means of quick return or rapid adjustment of the
screw spindle.
2, The improved mechanism for putting into and out of gear screwed spindles
substantially as hereinbefore described, with reference to the accompanying
drawings.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Her Majesty's Stationery Office, by Malcomson & Co., Ltd.-1898