Improvements in Tack-driving Mechanism for use in the Manufacture of Harvester-conveyers and for other purposes.
Year: 1892

page_text: Date of Application, 16th Apr., 1892-Accepted, 21st May, 1892
COMPLETE SPECIFICATION.
Improvements in Tack-driving Mechanism for use in the Manufacture
of Harvester-conveyers and for other purposes.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Chartered Patent Agent, do hereby declare
the nature of this invention (a communication to me from Cyrus H. McCormick, of
Chicago, in the County of Cook, State of Illinois, one of the United States of
America,) 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 primarily to mechanism for use in machines for applying
slats to canvas aprons for harvester-conveyers, and it will accordingly be described
in connection with certain features of such a machine; although the invention is
not limited to any such specific use, but may be employed for other purposes.
The invention consists, first, in a novel feed-device for bringing the tacks under
the operation of the drivers; secondly, in improvements in the drivers and in the
guides therefor; thirdly, in an improved mode of operating the drivers; and, lastly,
in various subordinate features and details of construction.
In the accompanying drawings, which serve to illustrate this invention,
Fig. 1 is a plan of part of a slat-tacking machine embodying the present
improvements.
Fig. 2 is a view partly in rear elevation and partly in section on the line 2, 2 in
Fig. 1.
Fig 3 is a longitudinal section on the line 3, 3 in Fig. 1.
Fig. 4 is a section, on the line 4, in Fig. 5, shewing a detail pertaining to the
tack-feeding and driving mechanisin. (Figs. 4 to 8 are drawn to a larger scale than
Figs. 1 to 3.)
Fig. 5 is a section on the line 5, 5 in Fig. 4.
Fig. 6 is a section on the line 6, 6 in Fig. 8, representing a tack-driver and its
guide.
Fig. 7 is a corresponding view on the line 7, 7 in Fig. 8.
Fig. 8 is a plan of the under side of the tack-driver and its guide.
Figs. 9, 10 and 11 are views (drawn to a larger scale than Figs. 4 to 8) of the
tack-driver and its guide, explaining the mode of releasing and driving the tacks.
The slat-conveyer comprises chains A led over sprocket-wheels at each end of the
machine; those at one end being driven. The chains are connected by slat-
carriers B, which extend across the machine from one side to the other at right
angles to the movement of the conveyer. Each has a longitudinal pocket to
receive a slat. The carrier is drawn by the chains over an anvil C, upon which it
temporarily rests while the tack-drivers descend and insert a gang of tacks.
Vertically or nearly so above the anvil is an intermittingly-driven plunger-shaft D
furnished with eccentrics D' turning in yokes or straps at the upper ends of
links D³ jointed at their lower ends to a plunger-head D³, which works between
guides D attached to the sides of the frame; the timing being such that, as the
slat or other article is brought to rest on the anvil, the plunger-head descends to
actuate the drivers and insert the tacks.
The tacks which it is preferred to use are double-pointed or staple tacks, and
therefore the feed and driving devices will be described in reference to such tacks,
but ordinary single-pointed tacks may be employed in the machine, as will be
presently explained.
From a point suitably elevated above the anvil and the receiving devices, there
commence a number of tack-ways E consisting of bars set edgewise and of sufficient
thickness to be properly straddled by and guide a staple-tack. There are as many

page_text: tack-ways as drivers, and they lead downward and separate from one another so
that each may conduct tacks to its respective driver. At the point whence they
start, however, they are massed together almost parallel and with only such inter-
stices as will allow tacks that fail to straddle them to fall through freely into the
hopper beneath. Along the massed length they are enclosed at the head and sides
by a hopper E, termed the "sorting hopper," which, together with the tack-ways,
has a slight vibratory or sidewise movement communicated to it. Located beneath
the sorting hopper, and extending some distance beyond it, is a "receiving
hopper", whence the tacks can be scooped or shovelled up and thrown into the
sorting hopper, each to straddle a tack-way or to fall through one of the interstices
back into the receiving hopper.
The tack-ways are intercepted before they quite reach the gang-drivers by a
transverse shaft E³, which is intermittingly rocked (being rocked once to each
descent and rise of the plunger-head) by means of a rack E moving in a guide e
at one end of the machine, a pinion e with which the rack engages, and a connecting
rod e³ jointed to a crank e on the plunger-shaft. Any other suitable means may,
however, be employed for rocking the shaft. An intermittent feed-disc E' in
respect of each tack-way is carried by the shaft E. Each disc has a single notch e*,
so located that, as the shaft E' is turned on the descent of the plunger, the notch is
carried up, over and back to the terminus of the upper section of the corresponding
tack-way, which comes to a point near or is brought into contact with the periphery
of the disc. When, on the ascent of the plunger, the reverse movement of the
shaft Es takes place, such notch is carried up, over and down until it reaches the
upper end of the lower section of the tack-way, which also is in contact with
the periphery of the disc and is in line, or thereabouts, with the terminus of the
upper section, so that the notch when it arrives at the second section is considerable
lower than when it left the first.
As the upper portion of the feed-disc rises above the sloping line of the tack-
way, it serves as a cut-off between the two sections. To insure the cut-off action,
the disc is surmounted by a gravity-bar F, which is pivoted in a bracket f secured
to the under side of the tack-way. From the bracket to the terminus of the
upper section, the gravity-bar is parallel with the tack-way, but raised sufficiently
above it to permit the heads of the tacks to pass freely. The extremity of the
cut-off bar is curved over and rests upon the upper portion of the periphery of
the cut-off disc. Its lower end descends nearly to the lower section of the tack-
way being separated therefrom only by the width of the notch e. It may also
have a stop-finger f¹ playing in a slot in the cross-bar F', which serves to support
and direct the drivers and their guides and is termed the "cross-guide." This
finger serves to prevent the gravity-bar from sinking low enough to interfere with
the free feed of the tacks before they reach the disc. A spring-pressure device
may, however, be substituted for the gravity-bar.
The notch in the cut-off disc being of just sufficient depth and width to admit the
head of a single tack, it follows that, when the disc is so turned as to bring the
notch to the upper section, it receives a single tack from that section, which, on
the return movement, is carried beneath the gravity-bar (or spring-pressure device,
if used in lieu of the bar) and delivered to the lower section of the tack-way,
down which the said tack slides to take the place of the tack driven when the
plunger-head last descended.
To prevent the tack which, for the time being, rests against the cut-off disc from
being tipped too far, a bent wire or spring-stop F is attached to the bracket F³,
which supports the lower end of the tack-way from the cross-guide; the wire being
so arranged that its end comes against the side of the cut-off disc and controls the
point of the tack until the tack has been separated from the others and carried up
beneath the gravity-bar by the movement of the disc.
In driving staple-tacks to unite canvas aprons to their slats, it is important that,
when driven home, they shall lie diagonally across the slats. To accomplish this,
the lower section of the tack-way is curved beyond the cut-off disc, as shewn in

page_text: Fig. 5; the effect being that the tack is delivered at a suitable angle on to the
end of a spring F' secured at its upper end to the front of the cross-guide,
extending down along the face thereof, turned at f' to pass under the cross-guide,
and finally curved near f³, from which part the end 73 projects. The curved part
of the spring is struck by a cam or wedge, whereby the end f³ is pushed out of the
way at the proper moment, as hereinafter explained.
The driver-guides G, for preventing twist and for convenience of construction,
are rectangular in cross section. They are supported in oblique guides in the cross-
guide, wherein they play up and down, their normal position being somewhat above
the end of the spring F. The curved part of the spring F enters a cross-slot gl
in the lower end of the guide; its lower part f being brought adjacent to the
drive-way, as shewn in Fig. 10. The tack, as it rests upon the part ³, is located
immediately beneath the drive-way, in which, when the guide descends, it is received.
The guide passes over and along the tack until it comes into contact with the
material resting on the anvil, when it stops and holds the tack in position for the
descent of the driver (see Figs. 9 to 11); the end of the spring remaining,
however, undisturbed for the moment. The driver H has a disc at its upper end
which enters a groove on the under face of the plunger-head and is secured therein
by a plate. It is connected with its guide by means of a pin h, which works in a
longitudinal slot ¹ in one side of the guide; this slot being of sufficient length to
allow the guide to descend over the tack and come to a stop before any relative
movement takes place between it and the driver. Between the head of the latter
and the head of the guide, there is a coiled spring H', which encircles the driver
and is of sufficient strength to force down the guide on the descent of the plunger-
head and bring it firmly against the object to be tacked before the driver itself
begins to move. This provides for the tack being received and supported in the
drive-way in the guide before the driver is carried down upon its head. The main
part of the driver is a flat bar 2, which, in thickness and width corresponds with
the head of the tack, just filling the drive-way. The bar is furnished with a central
longitudinal rib h³, which in the present design extends entirely through that side
of the guide entered by the spring F. The lower end of this rib is inclined, and,
as the driver continues to descend after the guide comes to a stop, this end strikes
against the curved part of the spring and withdraws the end ³ (Fig. 11) from
beneath the head of the tack before the latter is struck by the driver; the way
being then clear for the driver to force the tack home.
The specific construction herein described may be varied without departing from
the principle of the invention. For instance, the tack-guides and cut-off disc,
instead of being adapted only for staple-tacks, may be grooved or.channelled for
the purpose of feeding single-pointed tacks. The receiving guide need not
necessarily he rectangular in outline so long as it is prevented from twisting in the
cross-guide. The tacks need not be driven obliquely. The gravity-bar may, as
previously stated, be replaced by a suitable spring-device lying over the upper
part of the cut-off disc, and the latter may be rocked by mechanism different to that
shewn. A different method of delivering the tacks to the tack-ways may be
employed.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
1. In tack-driving mechanism, the combination, with a tack-way and a driver, of
a notched cut-off disc and a rocking shaft upon which the latter is mounted, substan-
tially as and for the purposes herein set forth.
2. In tack-driving mechanism, the combination, with a tack-way and a driver, of
a notched cut-off disc, a rocking shaft upon which the disc is mounted, and a
gravity-bar lying over the disc, substantially as and for the purposes herein set
forth.
3. In tack-driving mechanism, the combination, with a tack-way and a driver, of
a notched cut-off disc, a rocking shaft upon which the disc is mounted, a gravity-bar

page_text: lying over the disc, and a bracket to which the bar is pivoted and thereby
connected to the tack-way, substantially as and for the purposes herein set forth.
4. In tack-driving mechanism, the combination, with a tack-way, of a notched
cut-off disc located between the upper and lower sections of the tack-way, a
projection on a spring to which the lower section delivers, the spring by which the
projection is carried, a reciprocating driver-guide arranged to descend over the
tack carried by the projection, a driver playing through the guide and furnished
with a spring, and an incline on the driver whereby the projection on the spring is
withdrawn as the driver descends, substantially as and for the purposes herein set
forth.
5. In tack-driving mechanism, the combination, with a tack-way and a notched
cut-off disc vibrating therein, of a gravity-bar above the tack-way and the disc, and
a spring-stop resting against the side of the said disc at the lower end of the
first section of the tack-way, substantially as and for the purposes herein set
forth.
6. In tack-driving mechanism, the combination, with a plunger-shaft, a plunger-
head, a cross-guide and a driver-guide playing therein, of a driver connected to the
guide by a pin working in a vertical slot, and a spring interposed between the driver
and the guide, substantially as and for the purposes herein set forth.
7. In tack-driving mechanism, the combination, with tack-guides and cut-off
discs, of a rocking shaft upon which the latter are mounted, a pinion on the shaft,
a rack engaging with the pinion, a crank upon the plunger-shaft, and a pin
connecting the rack with the crank, substantially, as and for the purposes herein
set forth.
8. In tack-driving mechanism, the combination, with a notched cut-off disc, a
divided tack-way having its lower section curved to deliver the tack obliquely, and
a cross-guide, of a driver-guide arranged obliquely to the cross-guide and recipro-
cating therein, a driver playing through the driver-guide, and a spring whereby
that guide is carried down over the tack before the driver descends to force the
tack home, substantially as and for the purposes herein set forth.
Dated the 16th day of April 1892.
G. G. M. HARDINGHAM.