Improvements in Paper-cutting Machines.
Year: 1895

page_text: Date of Application, 14th Mar., 1895
Complete Specification Left, 14th Jan.. 1896-Accepted, 15th Feb., 1896
Improvements in Paper-cutting Machines.
I, JOHN MELTON BLACK, of No. 56, Tabernacle Street, in the County of
London, Gentleman, do hereby declare the nature of this invention to be as
follows:-
:-
This invention relates to improvements in that class of guillotine paper cutting
machines in which the clamping of the paper to be cut is effected by means of a
weighted lever the improvements having for object to avoid the shock to the
machine now caused by the sudden fall of the said lever.
According to my invention I employ by preference a straight counterweighted
lever which lever is operated by a snail or other suitably shaped cam, working
against a curved recess on the underside of the weighted lever, in such a manner
that as the cam is revolved, the lever will be gradually lowered and raised for
clamping and releasing the paper to be cut, a sufficient dwell being provided for the
cutting.
Dated the 14th day of March 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
I, JOHN MELTON BLACK, of No. 56, Tabernacle Street, in the County of
London, Gentleman, 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 improvements in that class of guillotine paper-cutting
machines in which the clamping of the paper to be cut is effected by means of
a weighted lever, the improvements having for object to avoid the shock to the
machine now caused by the sudden fall of the said lever.
According to my invention 1 employ by preference a straight counterweighted
lever, which lever is operated by a snail or other suitably shaped cam, working
against its underside in such a manner that as the cam is revolved, the lever will be
gradually lowered and raised for clamping and releasing the paper to be cut, a
sufficient dwell being provided for the cutting.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is a front elevation of a machine of the kind referred to, and described
in the Specification of Letters Patent No 2362 of 1881.
Figures 2, 3 and 4 are views illustrating the operation of my snail-cam.
a is the clamp and 6 the lever arranged in connection with the same as described
in the Specification before referred to. C is my snail-cam which works against the
underside of the lever b.

page_text: By referring to Figures 2, 3 and 4 (Figure 2 illustrating the position of the cam
when the lever is in its highest position, Figure 3 the position of the cam when
the lever is in an intermediate position and Figure 4 the position of the cam when
the lever is in its lowest position) it will be seen that the lever will be gradually
lowered from its highest position to its lowest position, in which latter it bears upon
the hub or boss of the cam, so that the shock hereinbefore referred to is entirely
obviated. It will be understood that the reason why this gradual lowering takes
place and the shock is prevented is that the point of contact between the lever and
the operating device (instead of being always between the lever and the pin of the
crank as heretofore) is gradually shifted from the extremity of the cam to the boss
as the lever descends.
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 I
claim is :-
:-
1. The improvements in guillotine paper-cutting machines, consisting in operating
the weighted clamping lever through the medium of a snail or other suitably shaped
cam substantially as, and for the purpose, described.
2. The improvements in guillotine paper-cutting machines hereinbefore described
and illustrated in the accompanying drawing.
Dated this 14th day of January 1896.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.