Improvements in Percussive Apparatus for Riveting, Caulking, and like Operations.
Year: 1898

page_text: Improvements in Percussive Apparatus for Riveting, Caulking,
and like Operations.
I, JAMES MACEWAN Ross, of the Firm of R. G. Ross and Son, Engineers, Green-
head Works, Glasgow, in the County of Lanark, do hereby declare the nature
of this invention to be as follows:-
This invention relates to percussive apparatus of the kind described in the
Specification of Letters Patent granted to me No. 16355 of 1892, and it has for its
object to make provision whereby the vibration due to rapid reciprocation of
the pistons and compression of the motive fluid is diminished or eliminated, and
also to provide means for maintaining in the open or closed position the valve
controlling the admission or exhaust of the actuating fluid.
In order to reduce vibration by preventing sudden compression of the actuating
fluid confined in the cylinder at the rear of the reciprocating piston or plunger
of the apparatus, I form a short cylindrical cavity at the rear end of the casing
preferably of slightly greater diameter than the piston or the liner in which the
piston works and I fit therein a piston or plunger which by means of a spring or
of the actuating fluid admitted behind it through a port or passage open to the
pressure fluid, is maintained normally close up against the end of the liner so as
to form a movable cylinder end or cover. When, during the reciprocation of the
acting piston of the apparatus, the actuating, fluid confined at the rear of the
piston between the latter and the movable cvlinder cover is compressed, this
cover or piston vields or slides back in its cavity until the pressure on both sides
is equalized, and the shock of sudden compression is avoided. In lieu of a mov-
able piston I may employ a diaphragm of leather, sheet metal or other material
to the rear of which the actuating fluid is admitted, or which is maintained in
position to constitute the cylinder end by means of a spring.
The valve which serves to start and stop the apparatus and which may be fitted
in the inlet or exhaust branch but is preferably fitted in the latter instead of
being operated by a trigger as described in the specification before referred to
is adapted to be turned or partially rotated when opening or closing the passage
for the actuating fluid or exhaust and it is operated by means of a pin or stud
screwed into it and passing through a curved or inclined slot in the valve casing.
A spring or the fluid pressure or like means is emploved to press forward the
valve so that the pin is maintained at either end of the slot while the valve orifice
is onen or closed, and in moving the pin within the slot it is in riding over the
inclined edge of the latter forced towards one end or the other. This slot may be

page_text: provided with notches so that the inlet or exhaust from the tool may be so
regulated that the strength of blow of the working piston may be varied.
Dated this 23rd day of February 1898.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,"
i
62, Saint Vincent Street, Glasgow,
Agent for the Applicant.
Improvements in Percussive Apparatus for Riveting, Caulking,
and like Operations.
I, JAMES MACEWAN Ross, of the Firm of R. G. Ross and Son, Engineers, Green-
head Works, Glasgow, in the County of Lanark, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention relates to percussive apparatus of the kind described in the
Specification of Letters Patent granted to me No. 16355 of 1892, and it has for its
object to make provision whereby the vibration due to rapid reciprocation of
the pistons and compression of the motive fluid is diminished or eliminated and
also to provide means for maintaining in the open or closed position the valve
controlling the admission or exhaust of the actuating fluid.
The invention is illustrated by the accompanying drawings, Figure 1 being
a longitudinal vertical section of the improved apparatus and Figure 2 a part
plan of the same.
In order to reduce vibration by preventing sudden compression of the actuating
fluid confined in the cylinder A at the rear of the reciprocating piston or
plunger B of the apparatus, I form a short cylindrical cavity A' at the rear end
of the casing preferably of slightly greater diameter than the piston B or the
liner C in which the piston B works and I fit therein a piston or plunger D
which by means of a spring or of the actuating fluid admitted behind it through
a port or passage A2 open to the pressure fluid, is maintained normally close up
against the end of the liner C so as to form a movable cylinder end or cover
for said liner. When, during the reciprocation of the acting piston B of the
apparatus, the actuating fluid confined at the rear of the piston between the
latter and the movable cylinder cover or piston D is compressed this cover or
piston D yields or slides back in its cavity A' until the pressure on both sides of
it is equalized, and the shock of sudden compression is avoided. In lieu of a
movable piston D, I may employ a diaphragm of leather, sheet metal or other
material to the rear of which the actuating fluid is admitted, or which is main-
tained in position to constitute the cylinder end by means of a spring.
The valve E which serves to start and stop the apparatus and which may be
fitted in the inlet A³ or exhaust branch A but is preferably fitted in the latter
as shewn instead of being operated by a trigger as described in the specification
before referred to, is adapted to be turned or partially rotated when opening or
closing the passage A6 for the actuating fluid or exhaust; and it is operated
by means of a pin or stud E¹ screwed into it and passing through a curved or
inclined slot A³, shewn particularly at Figure 2, in the valve casing' A'. A

page_text: spring For the fluid pressure or like means is employed to press forward the
valve so that the pin E¹ is maintained at either end of the slot while the valve
orifice is open or closed, and in moving the pin E¹ within the slot A5 it is in
riding over the inclined edges of the latter, forced towards one end or the other.
This slot may be provided with notches so that the inlet or exhaust from the
tool may be so regulated that the strength of blow of the working piston may
be varied.
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. The improved percussive apparatus for riveting, caulking and like operations
constructed and arranged to operate substantially as described.
2. In percussive, caulking and like apparatus such as described, a movable
piston or cylinder end held normally so as to form the cylinder end by means
of the actuating fluid or a spring and adapted to yield on the compression of
the actuating fluid between it and the working plunger so as to diminish or
eliminate vibration substantially in the manner described.
3. In percussive, caulking and like apparatus such as described an actuating
valve having a pin working in a curved or inclined slot in the valve casing to
open or close the valve whereby the valve is maintained by fluid or spring pressure
in its open or closed position substantially as described.
Dated this 23rd day of November 1898.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicant.