Improvements in Percussive Apparatus for Riveting, Caulking, and like Operations.
Year: 1892

page_text: Date of Application, 13th Sept., 1892-Accepted, 15th Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Percussive Apparatus for Riveting, Caulking, and
like Operations.
I, JAMES MACEWAN 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 to portable percussive apparatus for riveting, chipping
caulking and like operations, and the present improvements have for objects to
ensure efficient working of the apparatus and to provide greater facilities in fitting
and changing the operating tool. As represented in the accompanying drawings
in longitudinal section at Figure 1 and in cross section at Figures 2 and 3, the
improved apparatus is composed of a casing A having fixed in it a cylindrical
liner wherein reciprocates a piston C C¹ arranged to act as a hammer. The
piston is duplex or formed with two cylindrical heads or portions CC' fitting
the internal diameter of the liner and having a recess or portion of reduced
diameter connecting these two, whilst on its end is a boss C³ working in a guide-
way D in which the end of the caulking or other tool T is inserted. The com-
pressed air or other fluid for operating the piston enters by an inlet E and passes
through a series of ports to the inside of the liner B and into the recess between
the heads C C¹ of the piston. It thence passes through ports or passages 6' to the
space B' behind the head C and acting on the greater area at the rear of the
piston drives the piston forward until the ports 6' are closed and exhaust ports 62
are uncovered. At the same time ports ³ are uncovered by the movement of the
piston head C' and the fluid passing behind said piston head drives it in the opposite
direction until exhaust ports 6 are uncovered and the ports 61 again opened when
the motion of the piston is reversed. The exhaust from the ports 26 is led by a
passage to an outlet 66 covered by a sliding spring-actuated piston valve F
operated by a trigger G which is drawn from the position shown in full lines to
that represented by dotted lines by the finger of the operator who holds the
apparatus by means of a handle H. Upon the opening of the exhaust valve the
reciprocating action of the piston hammer begins the movements being short and
extremely rapid. The boss C² however does not strike the end of the tool T until
by applying pressure on the handle the said tool is pushed up into its socket against
the action of a spring I which bears on a removable washer J fitted in the socket
piece K and which keeps the tool normally out of the range of the hammer.
When the tool is pushed up by applying it to effect such operations as caulking or
chipping, so that the washer is in contact with the end D' of the guideway D, it is
within range of the haminer and greater or less movement is imparted to the tool
by the blows of the hammer by varying the thickness of the removable washer J.
The tool is simply inserted in its socket without any retaining catch and is readily
removed and replaced.
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 caulking riveting and like operations the parts of which are
constructed, combined and arranged to operate substantially as described with
reference to the annexed drawings.
2. In apparatus for caulking riveting and like operations the combination with a
casing or liner having admission and exhaust ports of a duplex piston, operating as
a self acting valve and serving as a hammer substantially as described.

page_text: 3. In apparatus for caulking riveting & like operations the provision in the tool
socket of a spring and washer arranged to keep the tool normally out of range of
the hammer substantially as described.
Dated this Ninth day of September 1892.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.