Improvements in the Manufacture of Bifurcated Rivets or Two Pronged U-shaped Fasteners for Leather or other Substances, and in Apparatus therefor.
Year: 1892

page_text: Date of Application, 16th Mar., 1892
Complete Specification Left, 16th Dec., 1892-Accepted, 11th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Bifurcated Rivets or Two
Pronged U-shaped Fasteners for Leather or other Substances,
and in Apparatus therefor.
I, SAMUEL CLELAND DAVIDSON of Sirocco Works, Belfast, Ireland,
Merchant, do hereby declare the nature of this invention to be as follows :-
The object of my invention is to cheaply and expeditiously manufacture bifur-
cated rivets or two-pronged U-shaped fasteners in which the interior surfaces of
the prongs taper outwards towards the ends, so as to form cutting edges on the
points, which when driven into leather or other such substance make cuts in same
which are in line with the exterior surfaces of a cross section of the prongs, and
the outward tapering of the interior edges of the prongs towards the ends, causes
them to so diverge outwards on being driven through substances such as leather,
that when the points emerge on the underside, and are forced or driven against a
metal or other hard smooth surface, they will turn outwards and upwards so as to
form a very strong and binding clinch on the underside, without the leather or
material between the prongs being severed or weakened thereby.
My improvements consist in forcing wire, preferably of half round or retangular
cross section, and cut to suitable lengths, through a die corresponding in shape with
an exact cross section of the exterior surface of the prongs of the rivet which is
to be made, by means of a punch having the exact form of the space that is to be
left between the interior surfaces of said prongs. As this punch is gradually
widened out towards the butt, so as to be of the same size as the die passing over
it, it is obvious that as the die passes onto the thick part of the punch, it will draw
the points or ends of the wire up to a sharp edge at the end of each prong, at the
point where the butt end of the punch exactly fits the die, and that any superfluous
metal at the ends of the wire will there be taken off by the edge of the die acting
against the close fitting surface of the punch. The die is so constructed that when
passed sufficiently far along the butt of the punch, the rivet points are projected:
clear through the back of the die, and when so projected the slight back spring
that still exists in the bent over prongs causes them to open slightly so that the die
on returning back off the punch catches the points of the prongs and pushes the
rivet in front of it so that it falls off the punch and out of the machine and the
die on returning to its original position is again ready to receive and similarly deal
with another length of wire.
•
I preferably feed in the wire between the punch and the front of the die off a
continuous length of wire by rollers, which grip it between them, and which by
regulated intermittent movements bring the proper length of wire between the die
and punch, and I have a cutter carried forward at the side of the die to cut off the
proper length of the wire for making the rivet, just as the punch begins to bend and
force the wire into the die at the centre of the cut length.
Where it is desired to impress any form or device on the head of the rivet, I
preferably as the first operation, give a short forward motion to the punch, and so
press the centre of the length of wire against a stationary anvil with the required
device in it so as to impress the device upon the wire, and I then move the die.,
forward to bend the ends of the wire over the punch to form the prongs of the rivet. :
The movement of the die or punch may be given either by hydraulic pressure, or
by any suitable combination of cams or cranks

page_text: My invention also comprises the apparatus arranged and working as above
explained for manufacturing my rivets or fastenings.
Dated this 16th day of March 1892.
J. C. MEWBURN,
55 and 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Bifurcated Rivets or Two
Pronged U-shaped Fasteners for Leather or other Substances,
and in Apparatus therefor.
I, SAMUEL CLELAND DAVIDSON of Sirocco Works, Belfast, Ireland, Merchant,
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 manufacture of bifurcated rivets or two pronged
U-shaped fasteners for leather or other substances, in which the interior faces of
the prongs taper outwards towards the ends, and the object of my invention is tu
cheaply and expeditiously manufacture rivets or fasteners of this class of such form
or shape that the interior faces of their prongs so merge into the exterior faces of
same that at their point of intersection they form cutting edges on the points of the
prongs, which edges, when driven into leather or other such substance, make cuts
in same which are in corresponding line with the exterior edges of a cross section
of the prongs, and the outward tapering of the interior faces of the prongs towards
the ends is such that when hammered or otherwise driven through substances such
as leather, and the points emerge on the under or opposite side, and are driven or
forced against a metal or other hard smooth surface, the thin edges of the points
of the prongs turn outwards and upwards so as to form a very strong and binding
clinch on that side, without the leathor or material between the prongs being
severed or weakened thereby.
According to my invention wire preferably of half round or rectangular cross
section, and cut to suitable lengths, is forced through a die corresponding in shape
with an exact cross section of the exterior faces of the prongs of the rivet which
is to be made, by means of a punch having the exact form of the space that is to
be left between the interior faces of said prongs. As this punch is gradually
widened out towards the butt, so as thereat to be of the same size as the die passing
over it, the die in passing along the punch to the thick part of the butt, gradually
draws the points or ends of the wire up to a sharp edge at the end of each prong,
at the point where the butt end of the punch exactly fits the die, and it is obvious
that any superfluous metal at the ends of the wire will there be taken off by the
edge of the die acting against the close fitting surface of the punch. The die is so
constructed that when passed sufficiently far along the butt of the punch, the rivet-
points are projected clear through the back of the die, and when so projected the
slight back-spring that still exists in the bent over prongs causes them to open
slightly, so that the back of the die on returning off the punch catches the points
of the prongs and pushes the rivet in front of it, so that it falls off the punch and
out of the machine; and the die on returning to its original position is again ready
to receive and similarly deal with another length of wire.
Preferably the wire is fed in between the punch and the front of the die off a
continuous length of wire, by rollers which grip it between them, and which by
regular intermittent movements bring the proper length of wire between the die
and punch, and the die is so constructed that one side of it acts as a cutter against
the edge of an orifice in a cutter plate connected with the punch and through which
the wire is fed in between the die and punch so that as the die moves forward it

page_text: cuts off the proper length of wire for making the rivet, just as the punch by its
resistance against the die begins to bend the wire at the centre of the cut length,
and to force it into and through the die.
Where it is desired to impress any form or device on the head of the rivet,
preferably as the first operation, a short forward motion is given to the punch, to
press the centre of the length of wire against a stationary anvil with the required
device in it whereby the device is impressed upon the wire, and then the die is
moved forward to bend the ends of the wire over the punch to form the prongs of
the rivet, as herein before described. The movements of the die or punch may be
given either by hydraulic pressure, or by any suitable arrangement of cams or
cranks.
The invention also comprises the apparatus arranged and working as above
explained for manufacturing my improved bifurcated rivets or U-shaped fasteners.
The accompanying drawings represent several forms or designs of bifurcated
rivets or U-shaped fasteners made in the manner hereinbefore described and also
two constructions of apparatus of my invention for carrying out the said mode or
process of manufacture.
In these drawings
Figure 1 is a view of a bifurcated rivet or U-shaped fastener in which the
interior faces of the bifurcation gradually taper in a straight line from the top of
the bifurcation out to the point of each prong.
Figure 2 is a view of a rivet or fastener in which a portion of the top end of the
prongs of the rivet is of uniform section or thickness and the tapering of said
prongs is carried from said portion of uniform section in a straight line to the
points.
Figure 3 is a view of a rivet or fastener the same as that shown in Figure 2
except that the tapering of the prongs to a point is by a curved instead of a
straight line.
Figure 4 is a side elevation of a form of apparatus actuated mechanically for
making the bifurcated rivets or fastenings without impressing any device on their
heads.
Figure 5 is a front elevation and
Figure 6 a plan of the apparatus shown in Figure 4.
Figure 7 is a side elevation, of a form of apparatus actuated by hydraulic
pressure for making the bifurcated rivets or fastenings and also impressing a
special device on the head of same; the hydraulic cylinders being shewn in
longitudinal section and part of the cutter plate being shown broken away to allow
the anvil to be seen.
Figure 8 is an end elevation of the apparatus shown in Figure 7.
Figure 9 is a section of same on line 9-9 looking in the direction of the
arrow and
Figure 10 is a plan of the apparatus.
Referring first to the apparatus shown in Figures 4, 5 and 6 AA represent the
cast iron frame and body or bed plate. is the driving shaft, B the driving pulley
and C the fly wheel. D' is a pinion on the driving shaft gearing with the spur
wheel D³ on a shaft d. E is a cam on the shaft d for giving to and fro movement
to the lever G a projection on which works in the cam groove. The lower end
of the lever G is pivoted at 9' to the frame A and its upper end which is slotted is
connected with one end of the lever G' whose other end carries the pawl J' so
that this pawl participates in the to and fro motion imparted to the lever G' from
the lever G. The movement of the pawl and of the lever G¹ is controlled by the
link g' one end of which is pivoted to the upper roller shaft h and its other end to.
the pawl spindle J. The pawl J' imparts intermittent motion to the ratchet
wheel J which is keyed on the shaft h of the upper feed rollers K and these rollers
consequently move with the ratchet wheel J. is a shaft carrying the lower feed
rollers K' each of which has a circumferential groove to receive and guide the
continuous length of wire from which the rivets are to be formed. LL are

page_text: adjusting screws and bearings for regulating the degree of tightness with which
the feed rollers K K grip the wire. The feed rollers are supported by the
brackets HH. M is one of the dies the number of which will be equal to that of
the pairs of feed, rollers K.K' three of which are shown by way of example in the
drawings. The dies are held in a carrier slide M' to which an up and down motion
is imparted by means of the crank F on the shaft d. N represents one of the
punches which in this case are fixed; these punches have the exact form of the
space that is to be left between the interior faces of the prongs of the rivets
while the hole or aperture in the corresponding dies M corresponds in shape
exactly with a cross section of the exterior faces of the prongs. Q is a cutter
plate having orifices 0 one for each wire through which said wire passes from
the feed rollers to the die and punch.
It will be readily understood that at each revolution of the driving shaft the
feed rollers by their intermittent movement imparted by the pawl J' feed through
each hole O a sufficient length of wire for one rivet, that the dies M then rise and
in so doing they each first cut off the length of wire against the edge of the
corresponding orifice O this side of the die being formed to act as a cutter and
then by passing over the punch N. bend the wire at the centre of the cut length,
the wire shaped into the form of a rivet being forced through the die. The dies
then descend ready for the next action while the pawl J' moves back ready to give
the next intermittent motion to the feed rollers K K'.
Figure 11 represents two elevations on a larger scale than Figures 4, 5 and 6 of
a punch N provided with side guide legs nn not shown in the other figures. These
guide legs for the punch proper do not come out of the die and therefore ensure
accuracy for the punch entering into the die. They are however not essential but
in practice I have found them desirable.
Figure 12 represents several views of the die M on a larger scale. The inlet m
at the top is very slightly widened and the top corner slightly bevelled so as to
avoid a sharp edge. This widening and bevelling are however not essential. The
groove m¹ forms the guide for the wire. n'n' represent the openings into which the
guide legs of the punch fit. The die is preferably made in two parts as indicated
by the line m³ in order that the grooving may be cut out accurately with a
milling tool.
Referring now to the modification shown in Figures 7 to 10 the punch N (the
apparatus is shown as having only one but there may be more) is carried by a
ram R working in a hydraulic cylinder R' and the die M by a ram R² working in
a hydraulic cylinder R. S' is the hydraulic supply pipe from the accumulator
and leading to a valve V. SS are two pipes leading from the valve V to the
two cylinders R³ R respectively. S is a hydraulic supply pipe always communi-
cating between the accumulator and the cylinders RR to effect the back stroke
of the rams. T is the exhaust pipe. U is a lever for working the valve V, P is the
stationary anvil by means of which the required device is impressed on the head of
the rivet; this anvil carried by the piece A'; the die carrier M' is forked so as
to clear this piece. When the lever U is worked in the one direction the valve V
first opens the way for the water under pressure to the cylinder R³, the ram R¹
therefore makes its forward stroke and presses the punch Ñ upon the wire against
the stationary anvil P so that the device on the anvil becomes impressed upon that
part of the wire which will become the head of the rivet, the length of wire is at
same time severed by the cutter plate passing the cutting edge of the die M, then
the valve V by its further movement opens the way for the water under pressure
to the cylinder R; the ram R' therefore makes its forward stroke and forces
forward the die M which in this movement shapes the wire over the punch into
a rivet. The lever U is now moved in the reverse direction and in this movement
it opens the exhaust of both cylinders R R* simultaneously and the water under
pressure in the pipe S by then acting in the annular spaces rr in these cylinders
carries both rams back and the finished rivet drops off the end of the punch as it
is withdrawn from the anvil. The wire may be fed to the punch and die in the

page_text: apparatus shown in Figures 7 to 10 either by hand or by a suitable arrangement of
feed rollers such as those described with reference to Figures 4, 5 and 6.
The apparatus shown in Figures 4, 5 and 6 can be adapted to impress a device
upon the head of a rivet by means of a forward movement imparted to the punch N
as described with reference to Figures 7 to 10 before the die M begins its move-
ment. The necessary movement of the punch can be effected in many obvious ways
such for example as fixing it in a slide to which a reciprocating movement is
given by a crank on the shaft d that is to say in the same way as the reciprocating
movement is given to the die M.
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. The mode herein before described of manufacturing bifurcated rivets or two
pronged U-shaped fasteners for leather or other substances with the cutting edges
of the points or prongs in the line of the exterior surface of the prongs, which
consists in forcing suitable lengths of wire by means of a punch through a die
whereby the wire is bent into the required shape and its ends are sharpened or
drawn out to the required edge by the combined action of the die and punch
substantially as set forth.
2. The combination of parts substantially as hereinbefore described with reference
to Figures 4, 5 and 6 of the accompanying drawings forming an apparatus for the
manufacture of bifurcated rivets or two pronged U-shaped fasteners of the kind
herein referred to.
3. The combination of parts substantially as hereinbefore described with reference
to Figures 7 to 10 of the accompanying drawings forming an apparatus for the
manufacture of bifurcated rivets or two pronged U-shaped fasteners of the kind
herein referred to.
4. The bifurcated rivet or two pronged U-shaped fastener manufactured in the
manner herein before described.
Dated this 16th dow of Decemb-1000
J. C. MEWBURN,
55 and 56, Chancery Lane, London, Chartered Patent Agent.