Improvements in Machine Dogs or Gripping Jaws.
Year: 1889

page_text: Date of Application, 14th May, 1889
Complete Specification Left, 12th Feb., 1890-Accepted, 15th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Machine Dogs or Gripping Jaws.
I. THOMAS WALTER BARBER of West Marina, St. Leonards on Sea, Engineer, do
hereby declare the nature of my said invention to be as follows :-
:-
My improved machine dogs are designed to be easily attached to either a lathe face
plate or machine bed of the usual kind having T grooves or slot holes in it and the
dogs may be fixed each by one or more bolts at any angle so as to grip articles of any
shape.
I construct each dog or jaw of a slide base which is secured to the machine by bolts
and which carries a sliding stepped jaw piece having a limited travel by means of a
screw which either turns in a nut formed by a projection from the fixed base, or in
bearings in the fixed base and in a half nut formed in the sliding jaw.
Instead of an ordinary screw to travel the sliding jaw, I also use a cam and lever,
or a wedge or colter, tapered sufficiently to give a short travel; as in setting the
article to be gripped the jaws can be placed close up before fixing to the machine bed
so that a short travel of the sliding jaw suffices to give the required grip.
By fixing three or four of these independent jaws to a machine bed any article can
be easily secured to it in a few minutes."
May 13th 1889
COMPLETE SPECIFICATION.
Improvements in Machine Dogs or Gripping Jaws..
I, THOMAS WALTER BARBER of West Marina, St. Leonards on Sea, Engineer, do
hereby declare the nature of my said invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the following
statement:-
My improved machine dogs are designed to be easily attached to either a lathe face-
plate or machine bed, of the usual kinds, having T grooves or slot-holes in them; &
the dogs may be fixed by one or more bolts, at any angle, so as to grip articles of any
shape.
I construct each dog or jaw of two pieces A. & B., one sliding on the other. The
base slide B. is secured to the machine by bolts or studs C. and the stepped jaw-
piece A, has a limited travel by means of a screw D, which may either turn in a
bearing E in the base slide B. Fig. 2; or in a similar bearing in the jaw piece A.
Fig. 1; in one case the screw will travel with the sliding jaw piece A & in the other
case it only revolves.
The gripping faces of the jaw pieces, which may have any required number of
steps, may be made either straight or curved as required for different machines, & are
also fluted & hardened to enable them to hold the work firmly. Two, three or four of
these dogs may be used together, arranged at any angle to each other to suit the form
of article to be held, or as may suit the slot-holes or T-grooves in the machine bed or
lathe face plate.

page_text: Having now particularly described & ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is
The construction of gripping jaws in two parts, sliding one. on the other and
operated by a screw, as shewn & described in the drawings & specification; such jaws
from their form & compactness being applicable to any machine bed or lathe face-
plate having grooves or slot-holes in it.
Dotod:11th February 1890.
THOMAS WALTER BARBER...