IMPROVEMENTS IN PUNCHING MACHINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by George Jones at the Office of the
Commissioners of Patents on the 27th December 1881.
GEORGE JONES, Manager to Messieurs William Gray and Company, Shipbuilders,
of West Hartlepool, in the County of Durham. "IMPROVEMENTS IN PUNCHING
MACHINES."
This Invention relates to improvements in the construction of punching machines
designed to enable a double row of bolt or rivet holes to be punched simultaneously
in metal plates, while also admitting of the punching of a single row throughout,
or the omission of any number of cither series of rivet holes. The improvements
are specially applicable to machines used for punching the shell plates of ships
which are double rivetted at the joints, and also to machines for punching boiler
plates; and a great saving in time and labour will be effected by the use of the
improved machines.
The Invention consists essentially in fitting the punch holders or rams of
punching machines with two punches, one of which is so fitted that it can be made
to punch the plate below it, or give way by moving within the punch holder or
ram when it moves downwards towards the plate. The holder or ram carrying both
punches is acted on by the usual moving lever framing through a tumbler piece,
which can be thrown out of gear or contact with the ram and stop the punching
without stopping the whole machine, while the plate is being adjusted in position
below the punches.
In carrying out the Invention machines may be used in which the framing and
actuating gear are of the ordinary construction; the ram or rams being preferably
connected to the lever arms which give them motion by a strong tumbler or
jointed link piece bearing over them, so that the rams may be thrown out of action
without entirely stopping the machine.
Two punches are fitted in the lower end of the ram, the one being held by a pin
much as usual in a hole or recess formed for it, while the other is fitted, in a
position to punch the holes at the desired distance apart, within a deeper hole or
recess with its upper end by preference bearing against a steel bolt within the
This hole or recess is of such a depth that when the punch and bolt are
fully entered within it, the cutting face of the punch is about flush or in a line
recess.

page_text: with the lower edge of the ram or punch holder. On a line with the upper end of
the hole or recess, a transverse slot is formed passing outside the ram, and a
moving steel bolt or stopper is fitted within it with a knob or handle outside.
This transverse bolt or stopper is pressed in to lio with its lower edge bearing over
the punch and vertical steel bolt, when the punch is projecting out from the face
of the ram, and in this position of the stopper the punch cannot move or give way
when the ram is depressed, but punches a hole through the plate.
When however it is desired to punch only the one row of holes, or when one or
more holes of the second row are to be omitted in punching, the transverse bolt or
stopper is withdrawn to a sufficient extent to allow the punch to rise in its recess
when it comes in contact with the plate being punched. The stopper is formed
with a bevilled edge so that if it should be imperfectly withdrawn, the punch or
bolt in rising will press it out.
Any other equivalent arrangement may be employed, for allowing one of the
punches to give way when it comes in contact with the plate being punched.
The punches and the dies through which the punched pieces are pressed, are
fitted so that different sizes of punches may be used, and so that the distance apart
of the punched holes may be reduced or increased according as smaller or larger
holes are punched.
For this purpose the larger sizes of punches are by preference made with the
cutting part or face slightly eccentric to the body of the punch, while the smaller
sizes may be concentric throughout, or formed in a similar manner, but with the
eccentricity of each punch towards the other, so that the holes may be punched a
little within the centre line of the punch body in this case, while in the first case the
holes will be a little without the centre line of the punches.
The punches may be fitted to punch the holes in line transversely, or at an angle-
to each other along-the-edge-of-the-plate.