Improvements in Devices for Cutting Picture Mounts and the like.
Year: 1897

page_text: Date of Application, 27th Apr., 1897-Accepted, 29th May, 1897
גטע עט עטUUM
Improvements in Devices for Cutting Picture Mounts and
the like.
I, WILLIAM HENRY MURDOCH of Youngstown, County of Mahoning,
Ohio, U.S.A., Furniture Dealer, 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 object of this invention is to provide a device for rapidly cutting openings
in picture mounts and like objects or materials on perfect right and uniform lines
and at any desired angle or bevel, and to operate which will not require skilled
labour.
In the accompanying drawing
Fig. 1 is a perspective view of the device of this invention. Fig. 2 an end view
thereof with certain parts shewn in dotted lines.
Fig. 3 a transverse section shewing in dotted lines the knife inclined.
Fig. 4 an enlarged view of part of one end of the device.
Fig. 5 an enlarged detail view of the knife seat, knife, and part of the knife.
carriage.
Fig. 6 an end view of Fig. 5.
Fig. 7 a detail edge and side view of the knife.
A is the base with upwardly projecting ends a, B a binding bar extending
between the ends a and serving as a clamp for holding the material to be cut,
properly upon the base. This binding bar is held normally elevated a slight
distance above the base A, by springs b, one end of each of which is secured to the bar
and the other end to the adjacent end a (Figs. 1, 3). To depress and hold the
binding bar down on the material it is preferred to employ a strap b' having a
stirrup 6 at its lower end to receive the foct of the operator. The front side of the
binding bar is preferably provided with a scale to enable the cut to be made of
precisely the desired length, and in the desired place in the sheet material, and
said front side is preferably bevelled to better expose the scale to the view of the
operator.
C is a guide bar attached to the base and extending through an aperture formed
in the lower part of one end of the binding bar. This guide bar comes at exact
right angles to the longitudinal line of the cut to be made and against it rests the
end of the material whereby all lines of cuts will be at right angles to and parallel
with the outer edge of the material and to further insure this, the guide is provided
with an adjustable slide c for engaging the edge of the material near the corner
thereof.
D is a guide rod located over and preferably parallel with the binding bar B,
the ends of said guide rod projecting through openings in the ends a that are larger
than the ends of the guide rod, and movable longitudinally upon this rod is the
knife carriage E having at the top a handle e for conveniently operating it, and
also having forwardly and downwardly extending arms to which is secured the
knife seat F of any suitable construction and preferably so attached to the arms el
that it may be adjusted to and held at any desired angle to produce cnts with
edges of any desired bevel. The means preferred for its attachment consist of
bolts or screws passing through clearing holes in the arms e¹ and into threaded
holes in the knife sent. The latter is also provided with a haudle f* for turning
LD 471

page_text: it to the required angle. F' is the knife, edged for cutting at its lower end and
held diagonally against its seat by a suitable clamping plate f.
Upon the guide rod D are one or two adjustable stops G for limiting the
movement of the knife carriage E to the desired length of cut.
H are springs which impinge against the ends of the guide rod D and tend to
force it towards one side of the openings in the ends a, and K are cams on the ends
of said rod which are designed to engage projections of plates L and force the rod
against the springs. The cams may be of any suitable construction and one of
them is provided with a handle k for operating them.
When the knife F¹ is out of engagement with the material, the springs H force
the rod D against the forward parts of the openings in the ends a. When however
the knife F in its inclined position is forced through the material, it is necessary
in order to accomplish a clean incision, that the knife shall move downwardly and
also slightly backward, and this backward movement is permitted by the enlarged
openings in the ends a. The knife, its carriage, and the rod D are therefore moved
slightly backward, against the resistance of the springs H, by the downward plunge
of the knife through the material. Now it is obvious that if the rod D is not locked in
the position it has thus assumed, as soon as the carriage is moved the pressure of
the springs H will tend to force the rod forward and with it the knife. The cut
would therefore not be in alignment with the first incision and consequently as
soon as this first incision is made the cams K are caused to engage the projections/
of plates L and until they are disengaged the rod D cannot be moved forward by
the action of the springs H.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
] claim is :-
1. In a device of the kind referred to, the combination with a knife carriage
and knife, of a guide rod upon which said knife carriage is movable, a spring for
pressing said guide rod in one direction, a cam upon said guide rod and a plate
engaged by the cam, for the purpose specified, substantially as described and
shewn.
2. In a device of the kind referred to the combination of the rod for guiding the
knife carriage, springs for pressing said rod in one direction and means for forcing
and locking the rod against the action of the springs, for the purpose specified,
substantially as described and shewn.
3. In a device of the kind referred to, the combination with the base having
upright ends formed with openings, plates secured to the ends and formed with
projections adjacent to said openings, a spring pressed guide rod extending loosely
through said openings and provided with cams for engaging said projections, a
handle for said rod, and cutting means guided by said rod, for the purpose specified,
substantially as described and shewn.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.