Improvements in or applicable to Punching or the like Machines in which Intense Pressure is Concentrated upon the Operating Tool or Appliance.
Year: 1892

page_text: Date of Application, 13th Feb., 1892-Accepted, 19th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in or applicable to Punching or the like Machines in
which Intense Pressure is Concentrated upon the Operating Tool
or Appliance.
I, THOMAS SNAITH, of 20, Swarthmore Terrace South, Stockton-on-Tees, in
the County of York, Foreman Engineer, 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 :-
My invention relates to the leverage mechanism of punching or the like machines
in which intense pressure is applied with a slow motion to the operating tool or
appliance after the manner described in my previous Patent of the 4th of September
1890, No. 13866.
The essential feature of my invention consists in improvements which further
conduce to the perfecting of the mechanism from which the intense pressure to be
exerted upon the operating tool or appliance is derived and which constitute with
the lever and toggle motion described in the Specification of my said Letters Patent
a new combination of parts by which the requisite pressure and motion is more
advantageously applied to the operating tool or appliance.
My invention is applicable to the above described lever and toggle motion
whether as designed for punching machines in which the maximum of power is
required early in the stroke, or for rivetting machines in which the maximum of
power is required at the end of the stroke, or for other machines in which the
pressure applied is preferably uniform throughout the stroke.
And in order that my invention may be clearly understood and readily carried
into effect, I will now refer to the accompanying drawings which illustrate my
improvements as applied to a punching machine, from which their application to
rivetting or other machines will be readily understood without further illustration
or description.
In the drawings, Figures 1 and 2 illustrate modifications of my invention as
applied to a punching machine, in which the toggle levers are worked from the
thrust of a screw shaft, which may be furnished with a right or left hand thread.
Figure 3 illustrates to a larger scale an inverted position of the screw shaft by
which a tensile strain is applied to the toggle levers; and Figure 4 illustrates to
the same scale as Figure 3, a modification of my invention by which a tensile strain
is applied to the toggle levers by means of a bell crank lever and connecting rod.
In the figures, A is the screw shaft which is screwed into a nut B which serves
as the knuckle joint between the toggles C' C. The lower toggle lever C¹ works
on the fulcrum or pin D which fits into the frame of the machine in the manner
shown at a position near to the joint on pin E which connects the leverage mechanism
with the operating tool. The upper toggle lever C³ works from a corrugated head
and toggle teeth F which engage with or fit into other toggle teeth F in the frame
head of the machine, and which are designed and adjusted to suit the intended
action of the operating tool in the manner described in the Specification of my
Letters Patent No. 13866 of 1890.
The leverage mechanism is put in motion by the rotation of the screw A
which is furnished at its outer end with a hand lever G, working in combination
with a ratchet wheel I and pawl H, the ratchet wheel being rigidly fixed on the
end of the shaft A, or other equivalent mechanism may be used for this purpose.
A collar J is secured to or forms part of the shaft A to which a collar K is also
securely attached, between these collars is placed sandwich fashion the boss or
flange L which is part of the rigid frame of the machine. As the toggle levers
move in and out, the screw shaft A will correspondingly vibrate or change the

page_text: line of its axis; this is provided for by a sufficiently slack fit of the screw shaft
in the hole in the boss L through which it passes, the surfaces of the_said_boss
being curved on either side to fit the concave surface of the. collar J, and the
convex surface of the collar K, all of which surfaces are curved in the manner
shown to suit the vibration of the screw shaft.
Figure 2 illustrates a modification which differs from Figure 1 principally in the
substitution of a nut M which can move about its centre for the fixed boss or
flange L about which the collars J and K move or slide as hereinbefore described;
two sides of the nut M are flattened to accomodate the collars J and K which
move as one piece with the nut M so as to allow for the requisite vibration in the
screw shaft A in working the toggle levers C¹ C³. The lower toggle lever C¹
may either work on a knuckle D' as shown in Figure 1, or on a pin D³ as shown in
Figure 2, the pin being a slack fit to accomodate the straight line motion of the
pin E.
Figure 3 shows the screw shaft applied in the reversed position so that the
toggles are actuated by a tensile strain therefrom instead of a thrust during the
operating stroke of the tool or appliance of the machine to which my invention is
applied.
Figure 4 illustrates a further modification of my invention by which toggle levers
are actuated by a tensile strain from the connecting rod N which is secured to the
knuckle joint B and is actuated by the bell crank lever P' P', which bell crank
lever can obviously be adjusted to afford any required amount of mechanical
advantage according to the relative lengths of the arms P' and P'. In this case
as in the case of the screw shaft the relative positions of the toggles and the bell
crank leverage connected thereto can be reversed, and a thrust applied to the
toggle levers instead of a tensile strain, but this is not to be preferred as it is
thought that when a tensile strain is applied whether with a bell crank lever and
connecting rod as described with reference to Figure 4, or with a screw shaft as
described with reference to Figure 3, more toggle teeth are brought into use on the
upper toggle lever C' and a correspondingly longer stroke can be imparted to the
operating tool of the machine in question.
From the foregoing description taken in connection with the accompanying
drawings, it will be observed that I have combined with my improved lever and
toggle motion a screw shaft or bell crank leverage for operating the same, all com-
bined together and constituting a simple, compactly arranged and powerful leverage
mechanism which can be readily applied to the operating tools of punching, rivetting
or other machines in which intense pressure is to be similarly exerted on the
operating tool or appliance.
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: :-
Firstly-In combination with my improved toggle levers as described and illus-
trated in the Specification of my Letters Patent No. 13866 of 1890, the use of the
screw shaft A working in a nut B which serves as the knuckle joint of the said
toggle levers, all constructed, arranged and operating together, substantially as
described with reference to Figures 1, 2 and 3 of the accompanying drawings.
Secondly-In combination with my improved toggle levers as described and illus-
trated in the Specification of my Letters Patent No. 13866 of 1890, the use of the
bell crank lever P₁ P' connected to the knuckle joint B of the said toggle levers,
all constructed, arranged and operating together, substantially as described with
reference to Figure 4 of the accompanying drawings.
Dated this 10th 1
L
1000
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.