Improvements in Percussive Apparatus for Rivetting, Caulking, and like Operations.
Year: 1890

page_text: Date of Application, 16th Sept., 1890
Complete Specification Left, 13th June, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Percussive Apparatus for Rivetting, Caulking,
and like Operations.
I, JAMES MCEWAN Ross of the firm of R. G. Ross & 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 mainly tofthat class of apparatus for rivetting caulking
and the like wherein a moving piston or striker is fitted to reciprocate and impart
a rapid succession of blows upon the end of a tool holder carrying a caulking or
other tool and the object of the improvements is to reduce the operating parts and
otherwise simplify such apparatus.
The improved apparatus comprises an outer casing between which and a
cylindrical liner are formed a series of inlet and exhaust passages having ports into
said liner for the passage of compressed air steam or other fluid actuating a piston
therein. To the outer casing the compressed air or other actuating fluid is admitted
first to an annular space across which is a dividing web or diaphragm to the farther
side of which the Huid can only pass through a tube having ports in it normally
closed by a piston valve held up by a spring but which is depressed by the hand of
the workman bearing on the end of the apparatus to make communication. through
the ports of the tube and thereby to admit the fluid to the inlet ports in the liner.
These inlet ports which are situated some distance apart serve to admit the fluid
alternately to either side of the piston which is an open ended cylinder with a
central web or piston proper i.e. in longitudinal section it is of H shape. The
piston shell is formed with inlet ports on each side of said partition these ports
being to about the extent of the stroke of the piston at less distance apart than
the inlet ports in the liner, so that when the upper ports are open to each other
and the fluid is admitted to the upper side of the piston, the piston is driven
down until the ports on the lower end are in line and the fluid enters at that end
to drive the piston up, the upper ports being then covered by the cylindrical
shell and an exhaust port being at the same time uncovered by the end of the
piston. On reaching the upper end of its stroke the upper inlet ports are again
open to each other the exhaust port at that end is covered and the exhaust port
at the lower end uncovered so that a fresh descent of the piston takes place
reciprocation of the piston being effected at an extremely rapid rate. On the
lower side of the piston proper is formed a long central boss or hammer the end of
which enters a guideway in an extension of which is fitted a tool holder or the
tool shank or spindle and at each downward stroke of the piston said boss or
hammer strikes the inner end of the tool holder or shank any yielding of which to
the blows of the hammer is counteracted by a spring packing or the admission of
part of the actuating fluid into an annular space in the guideway. The central boss
or striker may however be dispensed with by carrying the end of the tool holder
or the tool shank through the guideway so that it may be struck by the web or
partition of the piston. Also in lieu of the piston being of H-section a solid or
hollow cylindrical piston having closed ends may be employed the inlet ports in the
sides being carried up to the ends of the piston. In each case the piston is of
uniform diameter and acts as its own valve.
Dated thic Fifteenth day of September 1890.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Percussive Apparatus for Rivetting, Caulking,
and like Operations.
I, JAMES MCEWAN Ross of the firm of R. G. Ross & 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 particularly
described and ascertained in and by the following statement :-
This invention relates mainly to that class of apparatus for rivetting, caulking,
and the like wherein a moving piston or striker is fitted to reciprocate and impart
a rapid succession of blows upon the end of a tool holder carrying a caulking or
other tool and the object of the improvements is to reduce the operating parts and
otherwise simplify such apparatus.
In the accompanying drawings Figure 1 is a longitudinal vertical section of one
modification of the improved apparatus and Figures 2, 3 and 4 are transverse
vertical sections taken respectively at the lines 2-2, 3-3 and 4-4, of Figure 1.
Figures 5 and 6 are longitudinal vertical sections of other modifications of the
apparatus, Figures 7 and 8 are transverse vertical sections taken respectively at
the lines 7-7 and 8-8 of Figure 6, and Figure 9 is an elevation of the liner of
the apparatus shewn at Figure 6.
The improved apparatus comprises an outer casing A between which and a
cylindrical liner B are formed a series of inlet and exhaust passages a, a and b, b.
having ports a', a' and b¹, b' into said liner for the passage of compressed air steam
or other fluid actuating a piston therein.
As shewn at Figures 1, 2, 3 and 4 the compressed air or other actuating fluid is
admitted through an opening A' in the outer casing first to an annular space C
across which is a dividing web or diaphragm C' to the farther side of which the
fluid can only pass through a tube D having ports d in it normally closed by a
piston valve E held up by a spring F but which is depressed by the hand of the
workman bearing on the end of the apparatus to make communication through the
ports d of the tube D and thereby to admit the fluid to the passage a and inlet
ports a' in the liner B. These inlet ports a¹ which are situated some distance apart
serve to admit the fluid alternately to either side of the piston G which is an open.
ended cylinder with a central web or piston proper G₁ i.e. in longitudinal section it
is of shape. The piston shell G is formed with inlet ports g on each side of said!
partition these ports g, 9 being to about the extent of the stroke of the piston.at
less distance apart than the inlet ports a' a' in the liner, so that when the upper
ports a and g are open to each other and the fluid is admitted to the upper side of
the piston, the piston is driven down until the ports a¹ and g on the lower end are
in line and the fluid enters at that end to drive the piston up, the upper ports being
then covered by the cylindrical shell G and an exhaust port & being at the same
time uncovered by the end of the piston. On reaching the upper end of its stroke
the upper inlet ports a', g are again open to each other the exhaust port 61 at that
end is covered and the exhaust port 61 at the lower end uncovered so that a fresh
descent of the piston G takes place, reciprocation of the piston being effected at
an extremely rapid rate. On the lower side of the piston proper G₁ is formed a
long central boss or hammer G as is usual in such apparatus. The end of the
boss or hammer enters a guideway H in an extension of which is fitted a tool holder.
or the tool shank or spindle I, and at each downward stroke of the piston said boss
or hammer G2 strikes the inner end of the tool holder or shank I any yielding of
which to the blows of the hammer is counteracted. by a spring, packing, J or the
admission of part of the actuating fluid into an annular space in the guideway.
The central boss or striker may however be dispensed with by carrying the end of
the tool holder or the tool shank I through the guideway H so that it may be
struck by the web or partition G¹ of the piston as is represented at Figure 5.

page_text: In this modification Figure 5 the admission of the actuating fluid takes place
directly through the opening A¹ in the casing A to the inlet passage a the valve E
and accessories of the first modification being dispensed with and the operation of
the apparatus being controlled by a valve K fitted to close the exhaust outlet L
said valve K being operated against a spring K¹ by the thumb of the workman
who holds the apparatus by a handle M.
In lieu of the piston being of H-section a solid piston G as represented at
Figures 6, 7 and 8 or a hollow cylindrical piston having closed ends may be
employed the inlet ports g, g in the sides being carried up to the ends of the piston.
In this example also the operation of the tool is controlled by a valve K in the
exhaust passage the valve being worked by a trigger actuated by the finger of
the workman who grasps the apparatus by the handle M. In each case the piston
is of uniform diameter and acts as its own valve and the different forms of pistons
represented may be applied to any of the forms of casings shewn.
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. Apparatus for rivetting, caulking and like operations constructed substantially
as hereinbefore described.
2. In apparatus for rivetting, caulking and like operations a piston of uniform
diameter acting as the admission and exhaust valve for the actuating fluid sub-
stantially as described.
Dated this Eleventh day of June 1891.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.