Improvements in Portable Pneumatic Tools for Rivetting.
Year: 1899

page_text: Date of Application, 20th Nov., 1899-Accepted, 3rd Feb.,
1900
COMPLETE SPECIFICATION.
Improvements in Portable Pneumatic Tools for Rivetting.
I, HENRY JAMES KIMMAN, of 1235, Lawndale Avenue, Chicago, Cook County,
Illinois, United State of America, Machinist, 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:-
The invention relates principally to that class of portable pneumatic tools known
as rivetting machines in which there is a holder provided with clamping
mechanism and a direct acting engine to operate upon the heading tool, all of
which will more fully hereinafter appear.
The leading feature of my invention consists in so forming the yoke with the
ordinary air operated plunger on one side so as to provide a holding piece ou
the other side of the yoke for receiving an ordinary pneumatic hammer, such as
used for chipping, caulking, and the like, and I interpose between the supply
pipe of the plunger and the inlet pipe of the ordinary pneumatic hammer, a
throttle valve which controls the admission of air into the machine.
In pneumatic rivetters, where a power operated plunger is employed to hold
up the rivet an ordinary hammer or a hammer without a handle is employed on
the other side of the yoke permanently mounted herein and is employed to head
the rivet. In this case a disadvantage arises of the air being admitted to both
sides of the yoke at the same time and blows are struck by the hammer frequently
with the plunger not in proper position. However when a light blow is required
to be struck by the hammer, correspondingly light pressure only is put upon the
plunger and it will be readily understood that whatever the blow of the hammer
is required to be, that the plunger should receive the full force of the power
to bring it up to its position.
Referring to the drawings,
Figure 1 is an elevation of a tool constructed in accordance with my improve
ments shown partly in section: Figure 2 a detail view of a portion of the clamping
mechanism, and Figure 3 an enlarged sectional detail of the main throttle valve
hereinafter more fully described.
In constructing a tool in accordance with my improvements I provide a
bifurcated or C-shaped frame portion A of the desired size and strength to hold
tho operative and other parts in position. One end of this frame portion is
provided with a fluid pressure chamber B having a reciprocating plunger B¹
movably mounted therein so that motive fluid may be used to move the plunger
upward and against the headed end of the rivet. This plunger with its motive
fluid acts in a duel capacity, first as a clamp, and secondly, as a counter-weight,
as will more fully hereinafter appear. The other end of the C-shaped frame is
provided with a clamped portion C split at c and provided with a clamping bolt C¹.
In the cylindrical opening c¹ of this clamp portion I insert a pneumatic hammer D
of any of the usual forms of construction. I provide the usual means by which
the clamping plunger B¹ may be operated, a pipe or tube E being provided

page_text: connected with a passage e in the frame portion, which in turn connects with the
fluid chamber at or near its rear end and behind the head of the plunger so
that when fluid under pressure is admitted to this chamber the plunger is moved
forward against the tension of a helical spring b. When the supply of motive
fluid is shut off this helical spring bacts to return the clamping plunger to its
normal position and out of engagement with the rivet.
It is highly desirable that a main supply valve or throttle valve be provided in
combination with the mechanism shown by which a supply of motive fluid may
be furnished, preferably firstly to the clamping plunger, and then to the pneu-
matic hammer, although it will be seen from the drawing that it is supplied to
both ends simultaneously, but the hammer is not put into operation until its
own trigger is operated. This enables the operator to use one hand for the
purpose of guiding the tool in position, and the other hand for the purpose of
operating the pneumatic hammer. In order to accomplish this result, the frame
portion is provided with a main inlet chamber G which is connected with the
inlet and which in turn may be connected, in any suitable manner with the
source of motive fluid such as compressed air. Arranged in this inlet is a main
throttle valve II which is normally held in its seat by means of a helical spring h
shown particularly in Figure 3. A throttle lever H is provided and pivotally
secured at to the handle portion in the desired position, so that it may strike a
loose pin which in turn moves the main throttle valve and is held in contact
against the throttle valve by means of the helical spring which operates the main
throttle valve in one direction.
In operation the main throttle lever is pressed inwardly against the handle
which action opens the main throttle valve and admits a supply of motive fluid
to the inlet chamber G. This main inlet chamber is connected with the fluid
pressure chamber of the clamping plunger by means of the pipe E above described
and is also connected with the pressure chamber of the pneumatic hammer by
means of the pipe I as shown in Figure 1, which being of the usual construction
and provided with its own throttle valve and throttle lever i, shown in Figure
of the drawings, enables the operator to use one hand for operating the main
throttle and guiding the tool, and the other for controlling the hammer.
In operation as a single machine for the purpose of rivetting, the tool is grasped
in the usual manner by passing the fingers of the hand through the opening H
so that the operator can guide it to bring the clamping plunger to one end of the
rivet, namely, the headed portion, and the heating tool of the pneumatic hammer
opposite the unfinished end. The main throttle valve is then operated which
admits a supply of fluid under pressure into the clamping plunger pressure
chamber which action forces the plunger outwardly and clamps both ends of the
rivet between such plunger and the heading tool. The operator can then use
his other hand to open the throttle valve of the pneumatic hammer when he
desires. The action of the pneumatic hammer therefore can be used efficiently
and quickly to head the unfinished end of the rivet.
One of the principal advantages obtained by the use of a tool provided with
my improvements is that any size of pneumatic hammer can be used in connection
with the tool, for instance, in some boilers or tanks small rivets only are used,
consequently it is desirable to use a tool capable of delivering a great number of
light strokes per minute. In large structures, however, large rivets are used,
and as a consequence, it is desirable to use a heavy operating hammer, all of which
can be obtained by the use of my improvements.
In rivetters hitherto used, an air operated plunger has been used and a special
form of pneumatic hammer has also been used, but the operations of such
rivetters have been that one throttle valve operated the whole. In my invention
I have provided two throttle valves, one valve operating the hammer in one end
of the yoke, and I provide my improvements consisting of a throttle valve inter-
posed in the supply pipe between the plunger and the hammer.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I wish it to be
distinctly understood that I do not claim in pneumatic rivetters a yoke per se,
or a yoke provided with an air operated plunger, or even a yoke provided with an
air operated plunger at one end and a special permanently fixed form of pneumatic
hammer at the other end, as these features have been known and used before, but
what I do claim is:-
1. In a pneumatic rivetter, the combination of the usual air pressure
plunger at one end of the yoke, with an ordinary pneumatic hammer such as is
used for caulking chipping and the like, at the other end of the yoke and a main
throttle valve interposed between said plunger and the ordinary pneumatic
hammer, substantially as described and illustrated in the accompanying drawings.
2. In pneumatic rivetters, a frame or yoke having an air operated plunger at
one end, an adjustable bearing at the other end, and a main throttle valve sub-
stantially as described and for the purposes herein set forth.
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for Applicant,
70/1 Palace Chambers, Westminster, S.W.